4

Systematic Survey on 35 mm High End Camera– History from Leica to SLR –Kosho Miura Abstract
The history of photography spans almost 200 years, and the cameras which capture them have also beenaround just as long. However, early cameras were large wooden boxes in the style of furniture, not precision
instruments as are today’s cameras. Although they became smaller thereafter with the evolution ofphotosensitized material, the box shape was still the norm at the end of the 19th century. It took a certain amountof time since the invention of the photograph for the camera to break away from the box and become an object
which is all-metallic, compact, and precise.
The prototype built by the genius Oskar Barnack as a hobby using 35 mm film changed the course of camera
history. This report covers the history of camera before this event in chapter 2, and the sequence of events after
the birth of this camera prototype in chapter 3. This camera was put into mass market after World War I under
the name Leica. This small camera, with a feel of precision far from the norm of the day, became widely used as
people embraced its portability and ease of use. This innovation came to affect the design and the technology,
even of today, about 100 years since its birth.
Other companies followed with competing models. The field developed dramatically as Contax, a rival model
introduced by camera industry leader Zeiss Ikon, competed with Leica. Chapter 4 of this report covers thesequence of these events.
Competition in developing Leica and Contax was fierce. Meanwhile, the world was heading toward World War
II. Its dark shadow brought a major influence on the evolution of cameras as compact optical military weapons.
In Japan, as well, the foundation was laid for compact camera development, as Leica copies were produced as
required by the military or imitations were made out of curiosity. This came to be the budding of compact precision
cameras in Japan.
During the war, production of cameras for civilian use was interrupted. However, manufacturers appeared after
the war, resuming production or changing their course from the optical weapon industry, making use ofaccumulated technology. They were joined by those attempting camera production for the first time. Perhaps the
feeling of precision and the presence exuded by the camera touched the heartstrings of the Japanese. A
pragmatic aspect of this was that camera production, high in added value compared to the raw materials, wasperfect for Japan, a resource-poor country.
Aided by special demand generated by the Korean War, the Japanese companies were closing in on theGerman companies, which had been forging ahead at the forefront of compact precision cameras. However, they
were given a harsh awakening at Photokina 1954 with the release of Leica M3. Facing the reality that they were
outperformed by a few paces in almost all areas, Japan was given a great shock. Yet again, the Japanese camera
industry was saved by the changing times. As the photography culture diversified, the tide turned away fromrangefinder models like Leica toward single-lens reflex cameras (SLRs). 35 mm SLRs also originated in Europe,
however, since skillful mechanisms were required to overcome their shortcomings, development in Europe
progressed slowly. The outcome was that SLRs made great strides in Japan after the shock of Leica M3.
Conquering the various shortcomings of SLRs one by one with idea and effort and continuing to supply low-cost,high-quality product in harmony with the craftsmanship in their nature resulted in Japan gaining the top global
share of the camera industry by the 1960s, ahead of West Germany. However, it is also true that, during thatprocess, many manufacturers inferior in originality or development capability were eliminated. Such processesof migration to SLRs and the background of the times are covered in chapter 5.
Chapter 6 examines the evolution and development of the many SLR functions led by Japan, especially thepath to automation, from the viewpoint of functions. The original vertical-travel shutters, downsizing of cameras,
automatic exposure, autofocus technology—these were independently developed by Japan, solidifying its
position. This place has not changed in recent days since the times have moved on to digital cameras.
Of the long history of cameras, this report is restricted to the 35 mm focal-plane shutter models which started
with Leica. It was written avoiding a technical report format throughout, with the intention for it to be easy to readfor many people with an interest in cameras.

 Profile

Kosho Miura
Senior Researcher, Center of the History of Japanese Industrial Technology, National Museum of Nature and Science
1977
1979
1979
2004
2009
2017
2017

Bachelor of Science, Division of Precision Engineering, Hokkaido
University
Master of Science, Division of Precision Engineering, Graduate
School, Hokkaido University
Joined Nippon Kogaku Kogyo Co., Ltd. (currently Nikon
Corporation), assigned to Camera Design Division, mainly
engaged in mechanical design of SLR cameras
Temporarily transferred to Sendai Nikon Corporation, engaged in
SLR camera production technology
Returned to Nikon Corporation, assigned to Imaging Product R &D Laboratory, mainly engaged in planning and development ofdigital SLR cameras
Retired from Nikon Corporation
Joined the Camera & Imaging Products Association, continue as amember to date

 Contents
1 Introduction ..................................................................... 1
2 History of Photography – Overview.................................. 3
3 The Birth of the Leica .................................................... 11
4 Development of the 35 mm Compact Precision Camera 21
5 From Leica Copies to SLRs ........................................... 39
6 Development of SLR Camera and Evolution ofTechnology ................................................................... 67
7 In Lieu of an Afterword ................................................ 103

1

Introduction

From the end of 2016 to the following year, a special
exhibition “Lascaux: The Cave Paintings of the Ice Age” washeld at the National Museum of Nature and Science in Ueno,
Tokyo. The animal paintings on the walls of the Lascaux Cavein France, rendered by unknown Cro-Magnon artists withlimited rock paints and primitive tallow lamps, overwhelmed
the viewers with their vivid likenesses that looked as though
the depictions would start moving at any moment.
What inspired the artists to produce such imagery was their
passion for keeping a faithful record of what they saw before
them. About 20,000 years later, perhaps with that same passion,a Frenchman invented a means for automatically andpermanently recording images, and the images taken remain as
the oldest photographs in the world. Over the course of thenext 190 years, the camera developed as a tool for capturing
images of equal fidelity.
Looking back at the history of the camera, in the early days,
large box-shaped cameras were used by professional
photographers. The equipment set was large and heavy, andtaking photographs was also an ambitious task, and hence, outof reach of the general public. As the handling ofphotosensitive materials became easier and sensitivity
improved, cameras gradually became smaller. It was aroundthe end of the 19th century that Kodak popularized small box
cameras at low prices for the purpose of popularizing
photography. As the culture of photography permeated thegeneral public, folding cameras evolved to increase portability.
These cameras differentiated into various types as the varietyof photosensitive materials increased.
In the first half of the 20th century, new trends such ascompact precision cameras that use 35 mm film such as the
Leica, twin-lens reflex (TLR) cameras that use medium format
film such as 120, and spring cameras emerged, and cameras
evolved into high-precision machines. Around this time,
Germany, with its cutting-edge optical and precision
processing technologies, emerged as a world leader in thecamera industry.
The most notable in this period of history is the Leica.
About 100 years ago, a camera handcrafted by Oskar Barnack,who worked for Ernst Leitz in Germany, using parts on handin the corner of his own laboratory for developing cine-camera
technology was, at the beginning, used by Barnack as a hobby,
but in 1925 was released as the compact precision Leicacamera in the wake of the recession after World War I.
The camera, featuring such a strange and unique style to theeyes of the people of that time, gradually gained acceptanceand positioned itself as the compact precision machine thatwould usher in the present age. Following the Leica, manycamera manufacturers began to manufacture cameras
emulating its style. The industry giant Zeiss Ikon competed forthe title with the Contax and, with these as inspiration, theemergence of compact precision cameras began in Japan. The
Japanese set about on a program of acquiring andaccumulating knowledge of Western technology and, with aspirit of ingenuity, dexterity, and perhaps a natural aptitude forcamera production, brought about the blossoming of thecamera industry in the desolate post-war environment.
At first, the cameras of Japan were nothing more thanimitations of German cameras represented by the Leica. But,
while following Germany’s lead, Japan soon found a way into
the single-lens reflex (SLR) genre and, in the 1960s, turned thetables on Germany in terms of production volume, and jumped
to top global market share holder in the camera industry. In the
1980s, the production volume of 35 mm cameras with focalplane shutters, mainly domestically produced SLR cameras,
reached as high as about 75% of the global market share1) and,while the automobile and other industries suffered from trade
friction between Japan and the United States, export barriers
were nonexistent due to the lack of rivals, and the industry
grew to the point of being called an ideal model for exported
industrial products. That trend continues to this day and, evenafter camera technology transitioned from silver halide todigital, Japan continues to dominate the global market share.
This paper first touches on the history of the camera, thenfocuses on the process of the birth of the Leica, the archetypeof modern compact precision cameras, and describes
important aspects of its innovative technology. Next, the paper
attempts a bird’s-eye-view systematic analysis of the Contax,
which made its debut following the Leica, and the blossomingof prewar domestic compact precision cameras, the camera
industry launched after the war and, starting from Chapter 5,
the transition to and progress in the development of SLR
cameras, mainly in terms of technical aspects.
The passion of the Cro-Magnons in Lascaux Cave, whose
artistry vividly portrayed animals with rock paints and tallow
lamps, must have been passed down to their descendants
through their DNA. Niépce of France left the first photographof mankind, Barnack of Germany gave birth to the Leica and,triggered by these, the manufacturing power of Japaneseengineers developed the compact precision camera.
The development of compact precision cameras lies in the
pursuit of automation, high speed, and high accuracy in order
to increase the size of the imaging area and improve
convenience. The developers solved problems gradually, butwith steady efforts. I would like to describe the technologicaldevelopment process of these developers in terms of not only
technical aspects but also the historical context and various
human narratives. It is my hope that these descriptions willserve as inspiration for future camera development.
There are various forms of cameras, and it would be very
interesting to add the 35 mm lens shutter (diaphragm shutter)camera, TLR camera, spring camera, and the like to thissystematic analysis, but such an endeavor would be a huge task.
This paper, therefore, focuses on rangefinder cameras and SLR
cameras that use 35 mm film as per the Leica, and those
History of Cement Manufacturing Technology

1equipped with focal-plane shutters. However, this paper also,
as an exception, touches on the lens shutter-equipped cameras
found in early SLR cameras. As for digital camera technology,
a technology systematization survey2) has already been
completed and is available for your reference.

2

References and citations
1) Japan Camera Industry Association, Nippon Kamera
Kōgyōshi [The History of the Camera in Japan], (Japan
Camera Industry Association, 1987), p.386.
2) Ōkawa, Motokazu. “Historical Development on Digital
Still Cameras” in Heisei 19-Nendo Gijutsu no Keitō-ka
Chōsa Hōkoku [2007 Survey Reports on the
Systemization of Technologies] (Tokyo: National
Museum of Nature and Science, 2008).

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March2

History of Photography – Overview

2.1 Birth and Development of Photography
In ancient times there must have been a strong human desire
to devise methods for retaining images projected on the humanretina that would last far into the future. One answer to thisdesire is painting. Eventually, humans noticed that a small holein the wall of a dark room projected a bright outdoor image on
the opposite side. Furthermore, it must have been a short timeafter the invention of the lens itself that humans realized thatusing a convex lens instead of a hole would give a brighter andclearer image. Based on this principle, a device for producing
a painting in sketch form was born. This is the camera obscura,which refers to a “dark room.”

Figure 2-1

Collaborator Louis Jacques Mandé Daguerre, who replaced
Niépce following Niépce’s unexpected death in 1833, devised
a new method and published it in August 1839. In this method,a sharp image is recorded by depositing iodine on a silverplated copper plate and forming an image of the subject
projected by a lens on the plate. The camera used by Daguerre
is called the daguerreotype after his name, and was released asa set of Giroux Daguerreotype cameras by Alphonse Giroux &Cie. of France. This huge “box” was the first camera on themarket. Daguerreotype photography spread throughout theworld in an instant, was introduced to Nagasaki in 1848, andthe photograph of Lord Shimazu Nariakira taken in 1861
remains the oldest daguerreotype image in Japan.

Sketch of Camera Obscura1)

As a development of this, it is natural to want toautomatically record a projected image as is. Attempts toward
this end were made and, in 1825, it was the French inventor
Joseph Nicéphore Niépce who succeeded in leaving behind an
optical image as a record. This involved thinly applying a layerof asphalt to a polished metal plate and recording the image
via the hardening action of the asphalt. This technique is called
heliography and, although it seems somewhat strange to equate
it to photography which is a recording of light, his photographcalled “View from the Window at Le Gras” remains the oldest
photograph known to history.

Photograph 2-2

Giroux Daguerreotype Camera(Provided by JCII Camera Museum)In 1841, William Henry Fox Talbot of England announced
a negative-positive method called calotype, which made it
possible to duplicate many photographs from a single originalplate. This is the basic method of the current silver halide
photography system.
The calotype was inferior in sharpness because it used paper
as the negative of the original plate, but in 1851 Frederick
Scott Archer of England developed a collodion wet plate
photography method of applying collodion (viscous liquid) to
glass and adhering silver nitrate, which is a photoconductor,
thereto. This method, which is less expensive than silver plateand offers better image quality than calotype, was widely
accepted, but had a drawback in that the wet plate had to bemade at the photoshoot site, and many techniques were sought
to overcome this drawback. Among these, the most practical
was the dry plate.
The dry plate was obtained by applying a gelatin silver
bromide emulsion to glass and drying the application, andPhotograph 2-1

View from the Window at Le Gras 2)offers good storability and relatively high sensitivity.
Improved storability led to industrialization and increased
availability, driving the dry plate’s popularity. Even now, thedry plate is used not only for recorded photographs but also,

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –3because it can realize complicated patterns in detail and has

wet plate and dry plate, finally reaching the 35 mm film. That

good flatness, is utilized for industrial applications such as theis the fertile soil that would produce the Leica and subsequent

manufacture of electronic parts.
Attempts were also made to apply the emulsion to a flexible
substrate rather than glass to improve portability. While
research on roll film based on synthetic resin celluloid had
been promoted since the 1880s, it was paper-based roll filmthat was put to practical use first. The Kodak, a box camera
released by Eastman Dry Plate & Film Company in 1888, wassold with a pre-loaded 100-exposure roll of paper-based film.
After taking photographs, the user would send the camera backto the company and later receive the developed photos and thecamera refilled with new film. Along with the catch phrase of
the time, “You press the button – we do the rest,” this box
camera concept was well-suited for the social situation at thattime when, unlike the present, a proper infrastructure was not
yet in place, and was a big hit. The Kodak represented anepoch-making business model that led to the modern, onetime-use camera represented by “QuickSnap.”

SLR cameras. In the following sections, I would like to look at

Photograph 2-3

The Kodak(Provided by JCII Camera Museum)

The Eastman Dry Plate & Film Company released the No.
1 Kodak following the Kodak, and subsequently
commercialized a series of variant models from the 1890s to
the 1910s featuring improvements such as a film celluloid baseand a better loading method, picture size, and shutter
mechanism.
The company, which was renamed Eastman Kodak
Company in 1892, diversified its roll film as its achievements
in breakthrough performance increased. A number was
assigned to each type of photosensitive material and, while thecompany started with type 101, there are now more than 30
different types. Of these, type 135 is the type with the 35 mm
film loaded in a predetermined cartridge, which is still used
today.
Originally, the 35 mm film was developed for movies and,as the name implies, has a width of 35 mm and perforations(feed holes) on both edges. The film was put to practical useon Thomas Edison's kinetoscope in 1891, which subsequently
became widely accepted for entertainment purposes andspread throughout the world, bringing the 35 mm film much
popularity as well.
Starting from the primitive heliography of Niépce,photography transitioned through the daguerreotype, calotype,4

the process of evolution of the camera as a photography tool,
staying close to the historical flow of photography
development.

2.2

Development of Camera Equipmentwith the Evolution of Photography

2.2.1
Evolution of the Box Camera
Cameras similar to the Giroux Daguerreotype camera
described above are called box cameras because of their large
wooden box shape, and are more like furniture than precision
machinery. In fact, furniture craftsmen often made them using
walnut wood used for furniture construction.
The sensitivity of the silver plate, which is a photosensitive
material, is extremely low, and requires several tens of minutesof exposure even in fine weather. The shutter, therefore, wassimply the opening and closing of the lens cap. To make one,a craftsman would simply fabricate a wooden box that does notleak light, attach a lens to the side of it, and provide a slide
mechanism for focusing and a silver plate holding mechanismon the opposite side. Then, similar to the camera obscura, thecraftsman would prepare a mirror tilted at 45 degrees to guidethe light beam to the focusing screen, which is on the upperside, for checking the focus. This is already the principle of the
SLR camera.
The silver plate itself after a photo was taken was forornamental use, making it necessary to use a somewhat large
silver plate from the start, which inevitably made the size ofthe camera exceptionally large. The Giroux Daguerreotype
camera, while having a picture size of 162 x 216 mm3), whichis almost the same as the current full-plate format used on fieldor studio cameras, involved a substantially large physicalcamera equipment setup.
In the era of wet plate photography, the number of users
increased, the photo-shooting area gradually expanded, and theequipment became smaller and lighter for outdoor
photography expeditions. In fact, it was around this time thatphotographs were actually taken at the summit of Mont Blanc,
Yosemite and the Grand Canyon4).
With the advent of the era of dry plates, resolution andsensitivity improved dramatically, and mobility further
increased. This is because the dry plate, which offers goodstorage stability, is suitable for carrying around, and allows
selection of various sizes as needed. In addition, the improved
resolution gave way to sufficient endurance for recording
keeping and ornamental use, even if the captured image was
not so large, and the improved sensitivity helped facilitate
handheld photography.
2.2.2

Eastman Kodak's Success and the Spread of
Small Box Cameras

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchWith the success of the Kodak, small box cameras and rollfilms became widespread, and Eastman Kodak continued to
expand its variations of film. At the same time, with thedevelopment and sale of new products, various models
emerged. For example, Eastman Kodak released the Pocket
Kodak in 1895, successfully downsizing the camera by
reducing the film and picture size. The picture size isapproximately 4 x 5 cm.
In 1900, the Brownie camera was released for only $1. The
picture size employed in this camera of approximately 6 x 6
cm is the so-called 6 x 6 format still widely used today.

be taken in sequence while replacing the dry plates. Because it
was small and lightweight, records indicate that, together with
the quarter-sized format released the following year, about 100
units were sold per month6).
2.2.3

Debut of the Folding Camera

The definition of a folding camera is somewhat ambiguous
due to its many variations. From a structural point of view,
some sources classify such cameras as clap cameras, selferecting cameras, spring cameras, view cameras and fieldcameras, but the precise boundaries are not clear and this paper
does not aim to redefine them. Herein, a camera that can bemade smaller than the size during use by employing a bellows
or something similar is called a folding camera, and among thefolding cameras, a camera that can be transformed from afolded state to a shooting state with a single touch is called aspring camera.
Starting from the “furniture-like” camera era, cameras weremade into a foldable type using the elasticity of a bellows orinto disassembly type called an Assembly Dark Box in order

Photograph 2-4

to reduce both size and weight. Yet, even after the emergence

Brownie Model B (First model)(Provided by JCII Camera Museum)of the roll film, the box camera represented by the Kodak

The trend of box cameras for amateurs, which originated in
the Kodak, also affected Japan, and in 1889 Arita Shokai
released the domestic box camera “Keiben Shashinki (Lightand Convenient Camera).” This camera used a quarter-sized(83 x 108 mm) dry plate.
The No. 1 Kodak, a roll film-type box camera, was imported
by Asanuma & Co., Ltd., a long-established photographic
material specialty store, in 1890, and production of Japanmade cameras (with imported lenses and dry plates) beganaround this time. The camera recognized as the first domestic
mass-produced camera for amateurs was the Cherry Hand
Camera released by Konishi Honten (later Konishiroku
Honten, Konishiroku Photo Industry, Co., Ltd., Konica andcurrently Konica Minolta) in 19035).

continued its unaesthetic box-shaped design. This seemingly
stemmed from both Eastman Kodak's policy that, rather thandevotion to the camera for its own sake, low cost is the shortcut
to making photography popular among the general public, andthe national character of the American people, the main market,
who valued practicality over aesthetic considerations.
That said, a type more portable than the box type also
emerged, and the No. 5 Folding Kodak released in 1890 and
the Folding Pocket Kodak released in 1897 were morecompact in size through the use of folding mechanisms thatutilized a bellows.

Photograph 2-6

Folding Pocket Kodak(Provided by JCII Camera Museum)

Photograph 2-5

Cherry Hand Camera(Provided by JCII Camera Museum)This camera is a cartridge type that is pre-loaded with six
small-sized (54 x 83 mm) dry plates, allowing photographs to
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –5

The resolution and sensitivity of photosensitive materials
gradually improved, driving picture size and lens size
reduction and hence camera miniaturization and weight
reduction. The blockbuster in this line was the Vest Pocket
Kodak, released in 1912.

Photograph 2-7

Vest Pocket Kodak(Provided by JCII Camera Museum)The so-called vest picture size of 4 x 6.5 cm that used
Eastman Kodak's 127 type film made exclusively for thiscamera is a size that can tolerate contact printing, and above
all fits inside the pocket of a vest as the name suggests when
the camera is folded. With the success of the Vest Pocket
Kodak, this camera form and the 127 type film enjoyed aworldwide boom, and similar cameras were produced in eachcountry.
As an aside, the early Vest Pocket Kodak used a single-lens(two lenses per group) meniscus lens, which required a lens
hood due to spherical aberration. However, photos taken
purposefully with the hood removed produced a soft focus
effect, and this photography method became famous in Japan.
In response to the success of Vest Pocket Kodak, in Japan,
the long-established Konishi Honten released the Pearlette, theJapanese version of this camera, made by its own
manufacturing factory, Rokuosha, in 1925. The Pearlettesubsequently became a long-selling product provided with
continuous improvements for over 20 years.

2.2.4

Spring Camera

1925 is the year the first 35 mm compact precision camera,
the Leica, was released. While this paper focuses on thesystematization of compact precision cameras that originatedin the Leica, the period from the 1910s to the late 1940s, thatis, from World War I to the end of World War II, was a periodof remarkable development for other camera types as well.
With this in mind, I will address the main subject in thefollowing chapters and momentarily touch on cameras offorms different from the Leica. In fact, in terms of sales
volume, this was an era when other camera types
overwhelmingly boasted higher figures than the expensive 35
mm compact precision camera. In addition, looking at thehistory of camera development in Japan, while there weremany manufacturers that launched cameras modeled after the
Leica, some manufacturers accumulated experience withpopular lens shutter cameras, spring cameras or TLR cameras
and then entered the SLR camera market without ever pursuingthe Leica form, including manufacturers that abruptly started
production with the SLR camera. From this point of view, it ismeaningful to discuss matters such as the historical context
and sequence of events.
In Germany, Carl Zeiss merged four leading German
camera manufacturers and established Zeiss Ikon in 1926 tocounter the recession after World War I, and in 1929 released
the Ikonta, the original spring camera. This release sparked thesignificant boom of the spring camera, a type of folding
camera.

Photograph 2-9

Ikonta I(Provided by JCII Camera Museum)

Photograph 2-8

Pearlette(Provided by JCII Camera Museum)6

As the name suggests, the spring camera utilizes a spring to
make it possible to open and close the camera with a single
touch and immediately start shooting. Note, however, that thename of “spring camera” is used mainly in Japan and is notcommon in foreign countries.
In the early days, this type of spring camera was often a 6 x
9 format camera like the Ikonta in the early days, but 6 x 6format and 6 x 4.5 format cameras gradually became
mainstream in Japan.
Domestic manufacturers that entered the market with the

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

spring camera include Takachiho Seisakusho (later Olympus
Optical Co., Ltd., currently Olympus), which was founded in
1919 with the manufacture of microscopes and started camera
production with the Semi-Olympus I in 1936, and Mamiya
Kōki Seisakusho(later Mamiya Optical, Mamiya-OP, Mamiya
Digital Imaging and currently Phase One Japan), which
simultaneously entered the camera business and released
Mamiya Six in 1940 with funding from the manufacture ofmoney registration machines.
Also, as the name implies, the Nichi-Doku Shashinki
Shoten (Japan-Germany Camera Company), which launched
operations in 1931 with the cooperation of German engineers,
commercialized models such as the Arcadia and Minolta Vest
after being renamed to Mechanismus Optik und Linsen vonTashima (later Chiyoda Kogaku Seiko Co., Ltd., Minolta
Camera, Minolta, and currently Konica Minolta), and released
the first domestic 6 x 4.5 format camera, the Semi-Minolta I,
in 1935.

Photograph 2-11

Rolleiflex(Provided by JCII Camera Museum)The upper lens of the TLR camera is used for the viewfinder,
and the lower lens is used for photography. The waist-level
finder offered the advantage of allowing the photographer toobserve an image from a favorable perspective, and thestructure, which utilized ample metal, conveyed a highprecision feel and won great popularity. While the frame wasa 6 x 6 format and initially used 117 film with six frames on aroll, soon 120 film with 12 frames on a roll became available.
The features of the TLR camera are utilized in portrait
Photograph 2-10

photography. With the waist-level finder, the photographer

Semi-Minolta I

assumes a posture of slightly bowing to the person who is the(Provided by JCII Camera Museum)

Many manufacturers entered the spring camera market
during this period for the reason that the lens and the camera
body where film is loaded are mechanically separated bymerely the bellows, making the camera easy to make, and the
body structure offers the manufacturing advantage of requiring
only the stamping of sheet metal.
In addition, from around 1930, manufacturers specializingin shutter manufacture emerged in Japan, and the purchase of
these shutters further facilitated camera manufacture and led
to the breakthrough of the spring camera.
In this way, the prewar to postwar period was a period of
increase in the number of domestic manufacturers entering thecamera industry from various backgrounds and, with theaddition of newly established manufacturers, a period ofaccumulation in development and production technology forlater rangefinder and SLR camera development.
2.2.5
Emergence of the TLR Camera
In 1929, Germany's Franke & Heidecke released theRolleiflex Original, a TLR camera with lenses having thesame focal length on the top and bottom.

subject, which is perceived as less aggressive.
After the release of the Rolleiflex, the Rolleicord, a lowpriced version, was released in 1933, ushering in the TLR
boom. The Minolta Flex Automat was released in Japan in1941 and, after the war, due to the simplicity of the structureof the TLR, the number of manufacturers entering the market
increased rapidly and an uneven mixture of brilliant andmediocre cameras came and went. There is even a famous
anecdote that “J, U and X are the only acronyms for TLR
camera names not used among the 26 letters of the alphabet.”
In 1948, the Mamiyaflex Junior, the longest domestic series,
was released.
There was a notable movement in domestic cameras. The
Ricohflex III, a TLR camera released by Riken Optical(currently Ricoh) in 1950, was released at an ultra-low price of
5,800 yen, compared to the general camera price of tens of
thousands of yen at that time. On the day of release, customers
seeking this camera queued up, surrounding the Ginza San-ai
Building of the distributor.7)

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –7

miniaturization, a roller blind type shutter was devised byreplacing the plate with a flexible curtain and winding theflexible curtain to improve space efficiency. In addition, arotary shutter also emerged in which, instead of operating
linearly like a guillotine shutter, a fixed shaft was provided
with a light-shielding plate that rotated around it. From thenon, the roller blind shutter was developed individually as a
focal-plane shutter via a cloth curtain retractable Thornton
shutter, and the rotary shutter was developed individually as alater lens shutter. Figure 2-2 shows the transition of shutter
development.

Photograph 2-12

Ricohflex III

Around 1845
Drop shutter(Guillotine shutter)(Provided by JCII Camera Museum)The domestic TLR camera had shortcomings and, while
efforts were continually made to address them, including the
introduction of new mechanisms such as lens interchange by
Mamiya Optical, the production of the Mamiya C330S in 1994
was virtually the last to be discontinued. Ten years after theend of the war, spring cameras and TLR cameras, which

Around 1853
Roller blind
shutter

1885
Thornton Shutter
Kershaw (UK)

Developed into a
focal-plane shutter

Around 1856
Rotary shutter

1881
Double-blade shutter
Zschskke (Germany)

Developed into alens shutter

Figure 2-2 Transition of Shutter Development

enjoyed such incredible success, gradually saw a downward

The development of the focal-plane shutter will be

trend. The instigator of this trend was the rapid entry of a group

described in subsequent chapters, and here, in this section, theof compact precision cameras that used the 35 mm film

lens shutter widely used in spring cameras and TLR cameras

originating from the Leica into the market.

will be briefly described.

2.3 Advances in Mechanisms in Modern
Cameras
While the previous sections have described the evolution
from the box camera to the folding camera and the emergence

The rotary shutter is a shutter that uses a spring or the liketo rotate a disc provided with a hole, momentarily allowing
imaging light to pass through the hole. The shutter that consistsof two blades, rather than one disc, that open and close on bothsides at the same time was invented by Zschskke in Germany
in 1881.8)of the spring camera and the TLR camera with the advent ofThis form of shutter in which multiple blades open andthe roll film and improvements in sensitivity and resolution,

close in coordination evolved into the lens shutter of today.

the following sections touch on the technological evolution ofDuring this time, companies such as Bausch & Lomb andvarious mechanisms inside the camera, from prewar to postwar,

Wollensak of the United States and Deckel and Gauthier ofwhich is closely related to discussions on the 35 mm compact

Germany competed to make technological improvements such

precision camera, the theme of this paper.

as extension of the shutter time, installation of a self-timer, acombined shutter blade and aperture, and a more compact andLens Shutter and Focal-Plane Shutter

thin size, releasing improved lens shutters one after another,

While daguerreotype photography takes several tens ofwhich greatly contributed to the development of shutter-minutes of exposure even during the day, deeming a shutter

equipped folding cameras, spring cameras and TLR cameras.

such as that of a modern camera unnecessary and the opening

It should be noted that lens shutters can be classified intoand closing of the cap in front of the lens sufficient for picture

before-the-lens shutters placed in front, behind-the-lenstaking, the increasing sensitivity of the wet plate and dry plate

shutters placed behind and between-the-lens shutters placed

made dedicated shutters necessary.

between a group of lenses, depending on the installation

2.3.1

In the early days when cameras such as the Kodak started

position with respect to the shooting lens. The current

to become popular, a plate with slits was simply driven in aconvention is the between-the-lens shutter because it enjoys

guillotine manner with springs or rubber. This form of shutter

the great advantage of being able to double as an aperture, andis called a guillotine shutter or a drop shutter. This shuttera regular lens shutter refers to this type.
In Japan, K. Hattori & Co., Ltd. instructed its affiliate
Seikosha (currently Seiko Precision) to manufacture shutters

involves a long travel distance, so the camera itself has to belarge. For this reason, in response to the demand for camera

8

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchby utilizing its watch manufacturing technology. In 1930, thecompany succeeded in developing the Magna, the first
domestically produced lens shutter modeled after a German
shutter.

Photograph 2-13 Magna9)

The Magna was incorporated into the Toko anastigmat lensmanufactured by Tokyo Optical Co., Ltd. (currently Topcon
Corporation, hereinafter referred to as Tokyo Optical) and,after being installed in the First hand camera of Minagawa
Shōten, was employed in many domestic cameras. Seikosha
continued to accumulate capabilities while releasing different
types of shutters, and in 1958 escaped the confines of being amere imitator of Germany, developed the #00SEIKOSHASLV based on its own technology, and contributed to thecommercialization

of

many

domestic

SLR

camerasincorporating lens shutters.

the camera, making the marks visible. The user would thenwind the film to a position where he or she could see the markon the back of the film. This back window is often red and istherefore called a “red window” in Japan. This is because film
is practically insensitive to the color red, and utilizing thisquality of film prevents light leakage. This principle is still in
use today, and the active international standard ISO 1203
defines the dimensions of the back-window position of
medium format cameras.
Instead of such a primitive principle, the automatic winding
stop mechanism automatically prevents further winding whena predetermined amount of winding is performed via theoperation of a knob or lever for winding. In this method, theamount of movement of the film is measured with a roller orthe like, and when the film is moved by a predeterminedamount, the winding stop is applied.
While the rise of the so-called spring camera is largely due
to the success of the Ikonta series, which was first released in
1929 by Zeiss Ikon, the automatic winding stop mechanism
was already employed in the 1930s. In Japan, in 1933, Konishi
Honten released the Pearl that adopted the same mechanism.
Of note is the Mamiya Six, released by Mamiya Kōki
Seisakusho in 1940. In addition to its automatic winding, thiscamera was also famous for its back-focusing mechanism,
which showed much originality in that focus adjustment wasby moving the film plane of the camera in and out. With theemployment of back-focusing, a coupled rangefinder can beeasily realized, which is proof that Japanese camera
development technology was already trying to break awayfrom mere overseas imitation at this time.

A division of Kobayashi Seiki Seisakusho in Nagasaki,
Toshima-ku also started to develop shutters and completed a
prototype in 1946, which was first installed in the Olympus Six
I. This shutter division was spun off as Copal Koki Co., Ltd.
(later Copal Co., Ltd, and currently Nidec Copal Corporation),and became a shutter manufacturer that greatly contributed not
only to the development of lens shutters but also to thedevelopment of focal-plane shutters.
In addition, Citizen Watch Co., Ltd, has been developing
lens shutters since around 1950. It is remarkably interesting tonote that, in terms of the concurrent development of industrial
structure, the watch industry utilized its specialty of precision
machining technology to embark on the development of
shutters, giving a strong boost to the camera industry.
Photograph 2-14 Mamiya Six

2.3.2
Automatic Winding Stop Mechanism
In a camera that uses roll film, it is necessary to wind thefilm to the next shooting position every time a photograph istaken. If the film is wound too much, a useless interval results
and the user can no longer take the predetermined number ofphotographs. If the film is insufficiently wound, the frame
overlaps with the previous frame. In early cameras such as the
Kodak, the backside of the roll film was marked at regularintervals, and a small back window was placed on the back of(Provided by JCII Camera Museum)2.3.3

Self-Cocking Mechanism

Self-cocking is a technology related to the interlocking offilm winding and shutter charge. In early roll film cameras, theshutter was charged and the film was wound independently,
but this independent method results in the risk of the film being
wound without the shutter being released and thus the waste ofa frame or, the reverse, the shutter being operated without the

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –9film being wound and thus a double image. The self-cocking
mechanism eliminates these dangers by charging the shutter
together with the winding of the film.
While the self-cocking mechanism was already employedin models such as the Leica I released in 1925 and theRolleiflex – the original TLR camera released in 1929, such amechanism could be relatively easily installed in thesecameras since the camera bodies had an integrated structure,making it easy to interlock the winding mechanism andshutter charge mechanism.
On the other hand, in a spring camera, due to its folding
structure, the lens, that is, the lens shutter and the film winding
mechanism are separated, which makes interlocking difficult.
Self-cocking with a medium format spring camera wasrealized for the first time with the Mamiya Six mentioned in
the previous section. In other words, the Mamiya Six is the
one-and-only camera that realized it all: automatic winding,back-focusing and self-cocking. Mamiya Seiichi, thedeveloper of the Mamiya Six, was an engineer involved in thedevelopment and trial production of cash registers, and was
also a photo enthusiast. Lamenting that many domestic
cameras at that time lacked durability, Mamiya Seiichi
designed the Mamiya Six by himself, and his originality andpassion are something to be remembered.

10

References and citations
1) JCII Camera Museum, Kamera Q&A Kamera ga
Wakaruten [Camera Q&A Understanding the Camera],
Pictorial Record (JC11 Camera Museum, 2013), p.2.
2) JCII Camera Museum, Shashin Gekijō Firumu to
Kamera no Monogatariten [Phototheatre: The Story
Behind Film and the Camera], Pictorial Record (JCII
Camera Museum, 1994), p.3.
3) JCII Camera Museum, Kaku Jidai ni Miru Gamen Saizu[Picture Sizes Viewed Era by Era], Pictorial Record(JCII Camera Museum, 1999), p.8.
4) JCII Camera Museum, Shashin Gekijō Firumu to
Kamera no Monogatariten [Phototheatre: The Story
Behind Film and the Camera], Pictorial Record p.6.
5) JCII Camera Museum, Nihon Kamera Souseiten[Creation of the Japanese Camera], Pictorial Record(JCII Camera Museum, 2003), p.4.
6) Kamei, Takeshi (Ed.). Nihon Shashinshi heno Shōgen(Ge) [Testimony to the History of Japanese Photography(Volume II)] (Tankosha, 1997), pp.163-164.
7) Kurashikku Kamera Senka No. 3 [All about Historical
Cameras No. 3], Sengo Kokusan Kamera no Ayumi[History of Domestic Cameras After the War], (Asahi
Sonorama, 1983), p.155.
8) JCII Camera Museum, “Hai Chīzu” Shunkan wo
Toraeru Shattāten [Shutters that Capture that “Say,Cheese!" Moment], Pictorial Record (JCII Camera
Museum, 2002), p.4.
9) Nakagawa, Tadashi. Seikosha Shattā Monogatari [TheSeikosha Shutter Story], (Asahi Sonorama, 1998), p.9.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

3

The Birth of the Leica

3.1 Oskar Barnack

Camera AG, hereinafter Leitz). The business at Leitz was

Oskar Barnack was born in Germany on November 1, 1879.
After completing compulsory education in Germany, Barnack
worked in various factories and continued his career within theapprenticeship system, which was a common practice at thetime, in order to develop his specialty in mechanicaltechnology. In later years, Barnack won second place in a local
chess tournament, so he undoubtedly had a knack for scienceand mathematics. His hobby was photography. With his heart
set on becoming a landscape painter as a child, Barnack
enjoyed a strong artistic sense, and his extraordinary talent inlandscape photography is evident from the work he left behind.
Being a photography-loving mechanical engineer, he musthave felt a great sense of accomplishment when he landed a
job at Carl Zeiss at the age of 22. However, Barnack could not
become a full-time employee at Zeiss. While normally talent
breeds success, his frail health held him back. One or twomonths out of the year, he had to rest to treat his chronic
bronchial catarrh1).

Photograph 3-1

projector-related development, and seemingly close to trial
production. There is no doubt that Leitz had high expectations
as they arranged, at the time of Barnack's transfer, a home withgood environment near his workplace and took care to ensure
he would return home and rest during lunch breaks2).
After transferring to Leitz, Barnack's talent blossomed. He
developed a prototype of the Ur-Leica (meaning the prototypeof the Leica) described later, which was commercialized afterWorld War I and generated a lot of buzz at the time. This
product saved Leitz from the hyperinflation that hit Germany
and the subsequent Great Depression, and was continually
improved, establishing a solid genre of compact precision
cameras.

3.2 Ur-Leica
Barnack, whose hobby was taking landscape photographs,
experienced physical difficulties on shooting expeditions. This
was an era when a large camera and its supporting tripod wererequired for a large, beautiful photo with high resolution, andthis equipment was difficult to carry for Barnack who lacked
physical strength. In the back of his mind, perhaps there wasalways an image of a compact camera completely different
from the conventional camera. After transferring to Leitz,
Barnack was fortunate to be in an environment where 35 mm
film was used, and soon a prototype materialized that would
later be called the Ur-Leica. At the same time, he came up withideas for getting big prints from small negative films, andstarted taking advantage of these innovations in his hobbies.

Oskar Barnack(Provided by Leica Camera Japan Co., Ltd.)In 1909, ICA AG was founded by the merger of leading
German camera manufacturers Huttig, Wünsche, Krugener
and Carl Zeiss Palmos, led by Carl Zeiss. Barnack was
temporarily transferred to ICA AG for a period of about twomonths in 1910. Barnack presented Mengel, who was the
director of ICA AG at that time, with the idea of a compact
camera that used 35 mm film, but Mengel was not interested.
It was in the spring of 1910 that Barnack was temporarily

Photograph 3-2 Ur-Leica3)

transferred to ICA AG and the fact that he retired within the

While this is the story that is commonly told today, somedisagree. Barnack is said to have developed a cine-camera forin-house use in the creation of test film for projectors, but thesensitivity of the 35 mm film at that time was unstable, andwhether or not the exposure was suitable was not known until
the image was taken. For this reason, a portion of the film toyear may be due to his disappointment that this project was not
adopted.
Barnack was invited to join Leitz on January 1, 1911, partly
because he was recommended by his Zeiss-era friend Mechau,
who had previously transferred to Ernst Leitz (currently Leica

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –11

be used needed to be cut out and exposed in advance to gauge
the sensitivity. With the sensitivity known in advance,development conditions and the like could be changed andfailures in production avoided. The theory is that a “filmsensitivity confirmation device” prototyped for that purpose
evolved into the Ur-Leica.
The fact that the shutter time of the Ur-Leica is only a single
speed of 1/40 of a second works in favor of this theory. This isbecause the cine-camera is single speed. Further, the magazine“Die Leica,” published in 1931, also mentions “for test
shooting of film” in Barnack's own recollection4), thereby
perhaps supporting this theory of the film sensitivity
confirmation device.
However, this theory contradicts the fact that Barnackpresented Mengel with the idea of a compact camera at ICA
AG before joining Leica. Further, to check the film sensitivity
for a cine-camera, it would be natural to make the picture size
the same as the 17 x 24 mm size of the cine-camera, but oddly
the size of the Ur-Leica is 24 x 36 mm.
Ultimately, perhaps the only conclusion that can be drawn
is that there were various ideas and prototypes before the UrLeica. While there may have been a 17 x 24 mm format, in
consideration of resolution, the format was probably 24 x 36
mm to enable use with hobby photography as well. While theoriginal idea may be backdated to the idea presented earlier by
Barnack at ICA AG and, after Barnack's transfer to Leitz,
could have been used for business purposes to confirm film
sensitivity in advance, the outcome of the various
improvements made to ensure availability for personal use as
well was most likely the Ur-Leica.
In any case, the Ur-Leica was completed by the hands ofBarnack in 1914 (there are various theories about the year
being another year, 1913 also being likely). There were two
Ur-Leica prototypes made by Barnack. One source indicates
three prototypes, but the third one was made after the decision
to put the product on the market, and is fairly advanced. Oneof the two Ur-Leica was given to Ernst Leitz, the President of
the company, and the other was used by Barnack himself forphotography.

3.3 Ur-Leica Features
The question, “What kind of camera was the Ur-Leica?”
gives us a glance into Barnack, “the mechanical engineer wholoves photography” and, with deep interest, I will consider thisquestion below.
3.3.1

Outer Appearance and Design

The outer appearance of the Ur-Leica is amazingly simple.
The housing is horizontally long and, when viewed from above,is an oval extended into a long circular shape. Modern film
cameras have a back cover (rear cover) that opens and closes

12

to make it easier to load the film, but the Ur-Leica is a closed
oval, and thus the film must be inserted from the bottom. In
return, the camera, not requiring a large opening, is durable.
Barnack most likely thought that bottom film loading was
acceptable as long as he could get used to it, and prioritizedstrength and ease of manufacture. At this time, there was nofilm cartridge yet, and the film required for photography wasloaded in a dark room.
In a cross-sectional view, the body is simple and can be
drawn by connecting left and right semicircles with two
straight lines, one above and one below, something an ordinary
designer could draw in ten seconds. It is amazing that this basic
design has been handed down as far as the modern Leica
successor group (including digital cameras). While today's
cameras are designed with ergonomics and the like in mind
and thus have a complex outer appearance that cannot be handdrawn and is defined by three-dimensional data, theuniversality of the outer design of the Leica, which can be
drawn with paper and pencil in minutes, is nothing but
impressive.
The housing having an oval shape is said to have been madeby crushing an aluminum pipe. Perhaps two round bars of apredetermined diameter and a block of that same thickness
were placed inside the pipe, and the aluminum pipe wascrushed with a hand press machine provided at a prototype site.
Calculating from the size of the Ur-Leica, it seems that a pipewith a diameter of about 100 mm was used. If a thicker pipe
were used, the housing of the Ur-Leica would also be larger,
which could have influenced the size of the camera to thepresent day. Or, conversely, was the thickness calculated first
and then a pipe chosen accordingly?
The housing was completed simply by providing holes forlenses and the film counter, holes for screws to support otherinternal mechanisms, and the like. It seems as if Barnack, who
was not good with drawings, made the camera effortlessly
through an intuitive process of physical manipulation.
A removable bottom lid was prepared for the bottom of the
housing, and the upper side was closed with the upper coverafter the mechanical parts were inserted. The layout was suchthat a knob for adjusting the driving speed (curtain speed) of
the shutter to some extent and a shutter release button wereplaced on the upper cover, but that was it. The reason why theoutside is blackened as a whole is probably to prevent the
influence of reflection since the device is basically a test
device related to light.
It should be noted that the position of the lens is shifted to
the right when facing the front. This is because the winding
shaft of the shutter curtain is placed on the left side as
described later, which proved successful in improving the holdfeeling with the right hand, and this asymmetry became thebasis of the camera design that continues to the present day.
This is proof of Barnack's true sense of taste.
This design and layout by Barnack seem to be a product of

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchcreative inspiration, but there is a theory that there may be aprecedent for these attributes. Carl Zeiss Palmos, a company
that merged with ICA AG, launched the Palmos RollfilmCamera in 1901 around the time of its predecessor, the Palmos.
This camera was the world's first focal-plane shutter roll film
camera, and offered a self-cocking mechanism as well. While,
above all, the size was different, the appearance, except for thelens part, was similar to that of the Ur-Leica.

used, which has the effect of improving the transmission
efficiency of the mechanical system. This arrangement also
made it possible to reduce the number of parts of theinterlocking mechanism, and thus perhaps can even be said tokill four birds with one stone.
The shutter speed is basically a single speed of 1/40 second,
but can be changed slightly by turning the adjustment knob on
top to change the tension of the shutter operating spring. Thisis most likely a specification made by Barnack with his
photography expeditions in mind.
When the decision was made to commercialize the camera
as the Leica I after World War I, the shutter was improved
from the primitive standard of the Ur-Leica to a more practicalone, providing various shutter speeds, a self-capping
mechanism (mechanism in which the shutter slit isautomatically closed during charging) and the like.

Photograph 3-3

Palmos Rollfilm-Camera

5)

Barnack, during the Carl Zeiss era, seems to have been
temporarily affiliated with the former Palmos factory6), and it
is possible that he saw the Palmos Rollfilm-Camera at thattime. Perhaps it was this camera that inspired the evolution of
the Ur-Leica.
As a mechanical designer involved in camera development,
I can agree with this theory. Personally, when I was struggling
to come up with an idea, a mentor told me that a good idea israrely something that strikes you like lightning, rather it issomething that is wrung out after accumulating knowledge andexperience, and thinking about and agonizing over a problem
day and night. Perhaps, for Barnack as well, the Palmos
Rollfilm-Camera existed as a latent, subliminal image in acorner of his mind filled with the experience and knowledge
he had acquired as a mechanical engineer, and the idea
naturally emerged like beads of sweat, organically manifesting
itself in the compact camera. Even the talented Barnack could
not create a masterpiece out of nothing.
3.3.2

Shutter

The structure of the focal-plane shutter mounted on the UrLeica is simply a slit in a yet primitive rubberized cloth curtain.
The arrangement is something to behold. As mentioned above,the shaft around which the shutter curtain is wound andremains in standby mode is positioned on the film windingknob side, thereby improving the holding feel of the right hand,
and the film winding shaft and the shutter are close to each

3.3.3

Film Winding Mechanism

The Ur-Leica required that the film be put in and taken out
in a dark room since the film magazine had not yet been
adopted, but included a combination of a sprocket and a spool,which was subsequently adopted by most cameras, as the film
winding mechanism. A sprocket is a gear in which teeth are
cut in correspondence with the perforations of the film, and aspool winds up the film fed out by the sprocket.
The film perforation has a pitch of 4.75 mm, and the film ispulled out 38 mm when fed in an amount equivalent to eightpitches, resulting in a picture frame width of 36 mm after
subtracting the interval of 2 mm between adjacent images. The
Ur-Leica is provided with an eight-tooth sprocket, making it
possible to wind one picture frame in a single rotation. A single
operation of the shutter winding shaft is substantiallyequivalent to one rotation, making interlocking extremely
simple. Barnack's rationality is demonstrated here as well.
3.3.4
Shutter Release Button
The shutter release button, which causes the shutter to travelin order to take a picture, is provided coaxially with thewinding knob. In subsequent commercial Leica models, theshutter release button is provided coaxially with the sprocket
shaft. These “coaxial” designs seemed to be Barnack's
preference, helping to simplify operating parts and offering
space-efficiency and rationality as internal mechanisms,
thereby here again confirming Barnack’s aptitude for designand his good sense of taste.

other, making interlocked charging possible. This is truly an
arrangement that kills two birds with one stone.
In addition, the so-called horizontal travel method in which
the shutter travels in the direction of the long side of the picture
frame was adopted so that, with the shutter winding shaft andfilm winding shaft arranged in parallel, a spur gear could be

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –13

3.3.5

Accessory Shoe and Eyelets for the Strap

The top cover of the Ur-Leica has a shoe seat for attachingaccessories. Barnack had installed a sports viewfinder here forchecking composition, but as the times progressed, optical
viewfinders and flash devices were also mounted here. Alongwith these developments, shoe seat dimensions werestandardized (ISO 518), and the latest digital cameras today
also have a shoe seat with substantially the same dimensions.
Eyelets for the strap can be seen on the left and right ends ofthe camera, but the idea of attaching a strap here is a modern
one and the result appears quite natural, without a sense ofincongruity even in modern camera designs. These eyelets
were omitted in the early days of commercial models, but wererevived with a more modern design with the Type III andsubsequent models.
Barnack's foresight, apparent in the fact that these
specifications are used in many cameras even today, more than
100 years after the design of the Ur-Leica, takes my breath
away.

3.4

in Barnack's camera, and was preoccupied with the war effort,
hurriedly producing military optical devices and the like.
In 1918, the war ended with Germany's defeat. Due to thesignificant depreciation of the mark, German camera products,
which were originally highly acclaimed for their good quality,
became easy to buy in other countries, and exports greatly
increased. The German camera industry developed rapidly,companies were pressed to increase production, andcompetition intensified between emerging manufacturers.
Nevertheless, clouds always follow sunshine, and thedepreciation of the mark was sharply resolved by Germany's
drastic monetary policy, causing the bubble of the German
export industry to burst as if all was a dream in the night, andthe number of camera sales plummeted, leaving thewarehouses of each company piled high with inventory.
At this point, Carl Zeiss Foundation made a bold move. It
merged ICA AG, Contessa-Nettel AG, Ernemann and Goerz
to create Zeiss Ikon. ICA AG itself was originally a merger ofseveral leading camera manufacturers as mentioned above, so
Zeiss Ikon was an immensely powerful camera manufacturer

Camera Industry after World War

indeed. Such a merger was at a level that would most likely be
stopped by the Antimonopoly Act of Japan if existent, but

One of the two produced Ur-Leica prototypes was used bybeing a turbulent period, was unproblematic.

Barnack, and the other was given to Ernst Leitz I, the President

On the other hand, Leitz faced adverse circumstances. The

of Leitz, but he was not very interested. Barnack himself seems

company was not a camera manufacturer and so did not benefit

to have used the camera on a daily basis, and various

much from the increase in exports due to the depreciation ofphotographs have been left behind. The famous ones include

the mark, and its sales of other optical products were sluggish.

“Flood in Wetzlar,” a series of photographs taken in 1920.

Layoffs was one path to survival, but the second generation
who succeeded Ernst Leitz I, either through sympathy orforesight (probably both), did not dismiss the company’s
talented workers, including field workers, and tried to survive
the crisis by launching something new to create work. One newpotential product that was selected was the Ur-Leica, also
called the “Barnack camera” within the company.
In 1920, the Ur-Leica No. 3 was completed and featured avariable shutter speed, making the product more commercially
viable. Then, in 1923, approximately 30 monitor samples(there are various theories on the quantity), which were later
referred to as the Null Leica series (also known as the 0 series

Photograph 3-4

Flood in Wetzlar(Provided by Leica Camera Japan Co., Ltd.)

since null means zero in German), were built at the so-called
mass production prototype level.

These photographs of the city of Wetzlar, home to the Leitz,
when damaged by the flooding of the Lahn, look like normal
photos to the modern eye. Yet, given that the general camera
at that time was large in size, these immersive photographs,
most likely taken in situations where a tripod could not be set,
were clearly innovative. It truly is proof of the high mobilityof the Leica.
World War I broke out in 1914 when the Ur-Leica was used
habitually by Barnack. Leitz no longer had time to be involved

14

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchPhotograph 3-5

Null Leica(Provided by JCII Camera Museum)The reputation of the Null Leica, both inside and outside thecompany, was not good. In the era of large-format
photography, no one thought that a camera that takes picturesslightly larger than a stamp would sell. However, a word from
Ernst Leitz II settled the course of action. It was decided at thispoint that the “Barnack camera” would be released onto theworld stage. It is an unwavering historical fact that thisdecision was a major turning point for Leitz and thesubsequent global camera industry.

3.5

Max Berek Lens

No matter how good the Leica camera is, the camera would
not sell if the shooting lens performance was poor. Moreover,
the Leica concept of making large prints from small negative
film required a lens having an extremely high resolution. It was
optical designer Max Berek who rose to meet this challenge.

Photograph 3-6 Max Berek(Provided by Leica Camera Japan Co., Ltd.)Even the mechanical design genius Barnack found opticaldesign beyond his reach. If you trace the history of the camera,
it is evident that there is a pattern of collaboration between
excellent mechanical designers and optical designers in thecreation of famous cameras. For example, the Olympus XA
was developed by the duo Maitani Yoshihisa and Hayamizu
Yoshisada. It was fortunate for Barnack that Berek spent about
the same time at Leitz as Barnack.
Berek joined Leitz in 1912, the year after Barnack joined.
He was seven years younger than Barnack, but his hobbies ofplaying chess and mountaineering were the same, making thetwo a good match from the beginning. Most likely, Berek
understood Barnack's requirements and offered the bestsolutions.

The first Leica on the market was initially equipped with thesame Leica Anastigmat as the Null Leica, but since anastigmat
is a general noun for an aberration-corrected lens, the lens was
soon renamed to Elmax, a Leitz proprietary lens. EL is anacronym for Ernst Leitz, MAX is taken from Berek’s name.
Comprising five elements in three groups, the Elmax was an
excellent lens. However, the productivity of the rear group,
which required the bonding of three elements, was not so good,
and thus a new design, the Elmar, with four elements in threegroups emerged. The Elmar name is said to be a combinationof Elmax and the ending of the mainstream Tessar used at thattime. All of these were designed by Berek and have a focal
length and open aperture of 50 mm and F3.5, respectively.
Berek subsequently continued to provide guidance on
optical design and optical designers for Leica lenses, andlaunched treasures such as the Hektor, Summicron and Telyt.
Without the Berek lenses, no matter how good the Leica was
as a camera, it would never have been able to compete with“the great” Carl Zeiss. It should be noted that Hektor seems to
be derived from the name of Berek's pet dog, delightfully
revealing his playful side.

3.6

Names and Classifications of
the Leica Models

The Leica I, released in 1925, has such a number ofvariations to the extent that each could be called a different
camera. These variations were given different model numbers
in Japan and the United States. Japanese A, B and C types
correspond to the I type in Germany. The A type is a fixed lens
type, the B type uses a lens shutter instead of a focal plane, andthe C type is an interchangeable lens type, all with completely
different specifications. In this paper, we will distinguish thesemodels as I(A), I(B) and I(C), which are relatively wellestablished as general names. Note that the design and concept
up to the IIIg, which follows the style of the early Leica, iscalled the Barnack Leica, and the 1954 M3 and later models
are called the M-type Leica. There is, however, a period of
overlap between the two, with the release of the IIIg being in
1957 after the M3.
Barnack Leica is classified into Type I, Type II and TypeIII. Roughly speaking, the classification depends on thepresence or absence of a rangefinder-coupled viewfinder andthe presence or absence of a low shutter speed. Type I hasneither, Type II has only the former, and Type III has both(with exceptions; for example, Type Ig does not have theformer but has the latter).

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –15

Each type has been improved, with Type III including
models III and IIIa to IIIg, each reflecting some form of modelchange. Even for cameras of the same type number, an attempt
to describe the variations in detail, such as the presence orabsence of the famous IIIf self-timer, would be an endless task,
and thus this paper describes the typical and characteristic
specifications, technologies and functions of each model andtouches on the scale of improvement as needed.

3.7 Emergence of the Leica I

3.8 Leica Shutter Mechanism
The most innovative part of the Leica I(A) is the shutter
mechanism. The model offered a variable shutter speed andself-capping during shutter charging, which was not possible
with the mass-produced prototype Null Leica. Of course, a
self-cocking mechanism was also installed.
The Barnack Leica, excluding the Leica I(B), a lens shutter
type, uses a horizontal focal-plane shutter. As shown in Figure
3-2, the shutter is equipped with a front curtain and a rearcurtain that operate independently.
Rear curtain drum
Rear curtain
winding shaft

In 1925, the Leica I(A) was released. This first commercial
Leica, without interchangeable lenses yet and without a built-

Front curtain
winding
shaft

in rangefinder, was not exactly a rangefinder model, but could
be provided as a set with a rangefinder as an accessory.

Front curtain ribbon
Rear curtain ribbon
Rear curtain
Front curtain
drum

Rear curtain
springFront curtain ribbon
Rear curtain ribbon
Front curtain

Figure 3-2

Photograph 3-7

Leica I(A)(Provided by JCII Camera Museum)

In consideration that this was an era in which rangefinders
as well as the 35 mm film itself were not common in the world
and prints were contact prints, Leitz was prudent tosimultaneously release film-developers and simple enlargers.
At first, the Leica, with all of its innovation, made the public
take a step back and view it at a distance, but there is adocument7) indicating that the camera became profitable in
1928, a few years after its release, revealing favorable sailing.
In fact, looking at the trends in sales (Figure 3-1), the numberof sales doubled from 1928 to 1929. Note that the slowdown
in 1930 is thought to be due to the Great Depression, theimpact of the launch of the rival Contax in 1933, and the war
situation after 1937.

Figure 3-1

16

In the charged state, the rear curtain is wound around therear curtain drum, and the upper and lower ribbons of the front
curtain are wound around the front curtain drum. The front
curtain and the rear curtain are pulled to the left (shutter travel
direction) by a torsion spring of the winding shaft on the left
side in the figure and, although not shown, travel when theirrespective locking hooks are released.
The shutter speed can be changed by shifting the timing at
which the hooks are released. The principle behind theoperation is explained in Figure 3-3. This figure shows theprinciple behind a slightly advanced focal-plane shutter, notthe focal-plane shutter in the early stages.
Governor

Rear curtain
drive spring

Front curtain

Year

Transition in Unit Sales of the Leica8)

Shutter release button

Rear curtain

Aperture
Front curtain drive spring

Inertial plate drive
springFigure 3-3
Trend in Unit Sales

Structure of Focal-Plane Shutter

Inertial plate
Release hook
Front curtain lock
Rear curtain control pin
hookFront curtain
Rear curtain lockcontrol pin
hookOperation Principle Diagram of Focal-Plane
Shutter

The aperture (opening) is the picture frame, which is
closed by the front curtain when the shutter is charged.
When the shutter release button is pressed down, the releasehook and the inertial plate are unlocked, and the inertial platestarts to travel to the left by the force of the inertial plate drive
spring. Two pins are provided on the inertial plate, and thefront curtain control pin on the left side first unlocks the front
curtain lock hook, causing the front curtain to travel to the left
and the shutter to open. Subsequently, the rear curtain control
pin on the inertial plate unlocks the rear curtain lock hook andcloses the shutter. This completes the exposure.
By shifting the position of the rear curtain control pin on the

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchinertial plate, it is possible to change the timing at which therear curtain is unlocked. For example, the timing at which therear curtain starts to travel is slightly delayed when the pin is
at position A, and further delayed when the pin is at position
B. That is, the shutter speed can be changed according to theposition of the rear curtain control pin. Turning the shutter dialis equivalent to changing the position of this rear curtain
control pin. As an aside, there are various ways to call thisinertial plate, and one shutter manufacturer called it the “drive
control cam.” My co-workers called the inertial plate “kanseitai” in Japanese. The Japanese word “kansei” has twomeanings: “control” or “inertia.” I recall when I was a new
employee, perplexed on whether the Japanese characters usedwere those for “control system” or for “inertial body,” asked
my boss which characters to use. His response was that bothare correct in meaning, thus at one's discretion, leaving mecompletely bemused.
The governor in the figure is for low shutter speeds and, by
varying the insertion amount, hinders the travel of the rearcurtain even after the rear current lock hook is unlocked,
making it possible to delay the timing at which the rear curtain
starts to travel in a stepwise manner. This made it possible toextend the low shutter speed, which was up to 1/25 throughType II, to 1 second in Type III and subsequent models.
However, in the case of the Leica, it was necessary to set
the low-speed shutter with the low-speed shutter dial provided
on the front of the camera, a shutter dial different from the
shutter dial on the top of the camera. Since the shutter speed is
set in two locations, this type is sometimes called a biaxial type.
However, this name can be easily mistaken for two winding
shafts of the shutter structure, so caution is required.
Also, with the Barnack Leica, a pin for changing the shutter
speed is provided directly on the shutter dial (though it issimple), so when the pin is released and the shutter travels, theshutter dial also rotates. If a finger by chance touched the
shutter dial during shooting, shutter unevenness would occur.
A “uniaxial non-rotating equidistant shutter” in which the
shutter dial does not rotate (non-rotating), high speed and low
speed are set with a single dial (uniaxial), and the spaces
between shutter speeds are equidistant was non-existent in theera of the Barnack Leica and, for such a feature, we would haveto wait for the Leica M3 in 1954.

available as an accessory. The range scale of the lens isadjusted to the distance to the subject read by the rangefinder.
Rangefinders were used by battleships to measure the distanceto enemy ships, and this principle was applied to cameras.

Photograph 3-8

Leica with Rangefinder(Provided by JCII Camera Museum)

Nippon Kogaku Kogyo Co., Ltd. (currently Nikon
Corporation, hereinafter Nippon Kogaku), which later becamea leading camera manufacturer, is also famous for its
rangefinders. At the time of the Russo-Japanese War, therangefinder was not yet domestically produced and was madein Britain. However, naturally, during World War II, orders
were given for domestic production. Since the rangefinder uses
the principle of triangulation, the longer the distance between
the left and right lenses (this is called the baseline length), thehigher the accuracy. The rangefinders mounted on thebattleships Yamato and Musashi were the largest in the world
at that time with a baseline length exceeding 15 m, while thebaseline length of the rangefinder mounted on the battleshipMikasa, which was used in the Russo-Japanese war, wasaround 1.5 m. The rangefinder protruding to the left and rightat the top of the bridge in Photograph 3-9 is that rangefinder.

3.9 Coupled Rangefinder Mechanism with
Leica II and Subsequent Models
The Leica I was not equipped with a rangefinder, but arangefinder that would attach to the top of the camera was
Photograph 3-9

Battleship Musashi Rangefinder(Provided by Yamato Museum)

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –17

While an external rangefinder was prepared for the Leica I,
the possibility existed that the rod-shaped object wouldinterfere with the operation dial when placed horizontally, or
hit something when placed vertically as shown in Photograph3-8. For this reason, the Type II released in 1932 had arangefinder built into the camera. This is a true “rangefinder”
camera. However, due to restrictions on the location of the
optical system, the baseline length became as short as about 38
mm. This shortness would prove to be a weak point incomparison to the rival Contax later, but this design thatcoexists well with operation systems such as the shutter dial
and winding knob is superior to the rugged Contax. Above all,the structure in which the rangefinder optical system forverifying composition is arranged between the rangefinder left
and right lenses is truly rational in terms of space efficiency,
design and functionality. Although rights for this invention of“installing a rangefinder between the rangefinder left and right
optical systems” could not be granted in Germany due to
Zeiss's prior application, the invention was registered in Japanas a utility model with a wide range of rights, causing muchtrouble for manufacturers in Japan when dealing with it.
This rangefinder is linked to distance adjustment of the lens.
The principle is illustrated in Figure 3-4.

due to the rotation of the ring is used for distance adjustment,
and the movement of the rear end due to one helicoid is used
for the rangefinder.
The basic principle of the coupled rangefinder mounted on
the Leica II is an extremely long-lived technology that has
been adopted even in the Leica M-A (typ127; released in 2014),
which is a remote descendant.

3.10 Destination of the Barnack Leica andFeatures of the Type III
In 1933, the Leica III featuring, for the first time in Leica
history, a low shutter speed of up to 1 second was released.
The Type II was released the previous year, so it was most
likely a marketing strategy to release the cameras together, onewith and one without a low speed range. Since then, sales
formats that respond to user needs continued, such as, forexample, the release of the IIIc followed by market
introduction of the competitively priced IIc and the Ic models
reflecting IIIc improvements, and are still relevant today.

Movable prism stand
Adjustment
screw

Movable prism

Photograph 3-10

Leica II

(Provided by JCII Camera Museum)Interlocking
lever

Fixed prism

Figure 3-4

Rotating shaft
Lens frame rear end

Roller

Coupled Rangefinder

When the distance ring of the lens is turned, the lens frame
rear end moves back and forth. The amount of displacement isthen read by a roller provided inside the lens mount on thecamera side, the movement is reduced by the coupling lever,and the movable prism of the rangefinder is slightly rotated.
The movable prism moves in the order of the arrows A to D in
the figure, and the distance ring of the lens and the movableprism are coupled. Since the shooting distance of the lens isrelated to the amount of change in the angle of the movableprism, all a user has to do is turn the distance ring of the lens
while looking through the rangefinder and take a photo at theposition where the left and right images align.
While it may seem difficult to replace the lens with a lenshaving a different focal length, this is non-problematic because
the displacement of the rear end of each lens coincides withthe shooting distance. Simply put, there are helicoids (screws)
in two places on the distance ring (this configuration is calleda double helicoid), the combined movement of both helicoids18

As explained in Figure 3-3, the low-speed shutter is realized
by delaying the start timing of the rear curtain using a slowspeed mechanism called a governor. Since the governor issimply an addition without requiring a change in the shutter
mechanism itself, the effort required for development was
minimal. In addition, although it is a minor improvement, theType III has a safety mechanism that prevents shutter
operation during rewinding and a diopter adjustment
mechanism in the finder. The Type III series started with the
IIIa and reached the IIIg released in 1957 (e is non-existent),
seven model numbers in total, and a very wide variety of
improved versions including variations within each model
were released. However, none of the models reflect a fullmodel change and, just like the addition of a low-speed shutter,each feature partial improvements and/or mechanism additions.
Here as well are glimpses of Barnack's development
philosophy.
The main improvements in the Type III series are briefly
described below. In the Type IIIa, the high-speed shutter was
reduced to 1/1000. This would be a rival to the Contax. From
the IIIc on, aluminum die-casting was adopted for the bodychassis. While aluminum die-casting was adopted from thestart with the Contax and was the standard for compact

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchprecision cameras even in later cameras, the Leica had a sheet
metal stamped chassis through the IIIb.
The adoption of sheet metal also seems to be a product ofBarnack's rationality. While aluminum die-casting allows
complex shapes, which increases the degree of freedom indesign, the mold is expensive and, once made, difficult tomodify. In that respect, sheet metal stamping offered a
relatively inexpensive mold that was easy to make small-scalecorrections to, and thus fitted Barnack’s way of camera
improvement, which was through a series of small
modifications.
The IIIc was released in 1940 and, with Barnack no longer
among the living, the successor designer chose die-casting,which can be more productive and stronger, but the size of thecamera slightly increased in width and height. Since the IIIc
was produced during the tumultuous postwar period, thequality of the parts was not consistent, causing many
individual products to be somewhat problematic. Yet, thismodel boasts the second largest production numbers following
the IIIf. The IIId, while produced in small numbers, is simply
the IIIc equipped with a self-timer.
The IIIf was the highest seller among the Barnack Leicas,
and is still a popular model today. For the first time in Leica
history, a synchro terminal was installed and a flash device
could be used. Each specification was refined, such as the
adoption of ball bearings in the internal mechanism. The IIIf
was released in 1950 and, having overcome the turmoil after
the war, the quality of the parts was more consistent, so theoverall quality of the camera was also higher. A model with aself-timer was also introduced midway through the series, andis still treated symbolically as a Barnack Leica.

Photograph 3-11

3.11 Death of Barnack
Barnack seems to have been involved in the development of
all models ranging from the first commercial Type I, of course,
to the Type III series. Naturally, it is clear that Barnack was
deeply involved in the development and design of various
mechanisms that were pioneering for the time, such as lensinterchange, rangefinder coupling and low shutter speed,
because his name is listed as the inventor in patents.
With the Ur-Leica, at the beginning of the 20th century,
having laid the foundation for compact precision cameras andsince then having been at the forefront of the times for morethan 20 years ... No, on the contrary ... With Barnack having
continued to influence the design, internal layout andmechanisms leading up to the current camera, Barnack's
passion and gifted talent should be considered immeasurable.
Barnack, the father of the modern compact precision camera,died of pneumonia in 1936 at the age of 56. Even in his later
years, when he was in good health, he would suddenly appear
at work and present new ideas. Leitz completed the trial
production of the Type IV in 1935 after the Type III, and thisprototype was partially equipped with the innovative
specifications and mechanisms of the M3 to be released after
the war. Meanwhile, in the early 1930s, the Nazis led by Hitler
took the stage, and war clouds loomed on the horizon. In this
disturbing atmosphere, the Type IV lost the opportunity to hit
the market, and the release of the M3 was delayed until 1954.
How would the camera have evolved if Barnack enjoyed along life and there was no war?
A photograph of Barnack taken at work in 1934 remains tothis day. He exhibits a firm gaze that makes it difficult toimagine that he would pass away just two years later, but thephoto being tinged with melancholy is impressive.

Leica IIIf

(Provided by JCII Camera Museum)The IIIg was the last Barnack Leica. The IIIg was released
in 1957, three years after the release of the innovative Leica
M3. The IIIg appears to be an effort to rescue those Leica fansthat could not keep up with the Barnack Leica and its bold
improvements such as a change in the lens mount with the M3,
and reflects ambitious improvements, such as the mounting ofa parallax correction mechanism and a viewfinder with a brightframe compatible with two types of lenses. In addition, it is the
IIIg that established the precedent of the shutter dialmagnification increments used today. Looking at the IIIg, it isunderstood that Leitz continued to develop the Barnack Leica
without cutting corners to the end.

Photograph 3-12Barnack in the Lab(Provided by Leica Camera Japan Co., Ltd.)

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –19

References and citations
1) Kondō, Hideki. Daremo Kakanakatta Raika Monogatari[The Untold Leica Story], (Shashin Kōgyō Shuppansha,
2001), p.66.
2) Keller, Emil G. Raika Monogatari: Daremo Shiranakatta
Raika no Himitsu [Leica im Spiegel der Erinnerungen],(Kojinsha, 2008), pp.44-45.
3) JCII Camera Museum, THE LEICA - Raika no Hyakunen[THE LEICA – One Hundred Years of The Leica],
Pictorial Record (JC11 Camera Museum, 2013), p.4.
4) Laney, Dennis. Raika Korekutāzu Gaido [The Leica

5)
6)
7)
8)

Collector's Guide], (Alpha Beta Publishing, 2000), p.16.
75 Jahre Photo und Kino Technik [75 Years of Photo andCinema Technology] (Zeiss Ikon), p.42.
Shōichirō, Takeda. Twuaisu Ikon Monogatari [The Zeiss
Ikon Story], (Kojinsha, 2010), pp.36-37.
Shōichirō, Takeda. Twuaisu Ikon Monogatari [The Zeiss
Ikon Story], p.105.
Laney, Dennis. Raika Korekutāzu Gaido [The Leica
Collector's Guide], p.12.

Why 36 Exposures?
Currently, for 35 mm cartridge film, 36 exposures is the standard, but this also originates with Barnack. Still image
cameras that used 35 mm film existed, but all of them were capable of a significantly higher number of exposures. The
reason for this is probably because of the prejudice that, if the camera is to use long movie film, it would be a loss to nothave a high number of exposures.
Barnack, without thinking much about stinginess, first determined the size of the camera based on portability and thenpacked the camera with an amount of film that would fit inside. The number of exposures was probably more than 40 andless than 50. The fact that the total number of Ur-Leica exposures is 50 at maximum confirms this.
However, with the commercialized Leica, it became necessary to put the film in a magazine and the size of the magazine
was determined based on an eyepiece case of a microscope that was lying around, making the number of exposures not ashigh as that of the Ur-Leica. Furthermore, unlike the Ur-Leica which was premised on dark room loading, the camera
required a blank feed, which further decreased the number of exposures.
An early pamphlet on how to use the camera included an honest note: "The film used is a 1.6 m negative film forcinematography offering 36 exposures.... We had initially planned to provide 40 exposures with 1.75 m of film, but this wasfound to be impossible, and thus settled on 36 exposures.” The thickness of the film at the time sometimes caused problems
when the film was rolled, which probably led to the writing of this explanation (Note 1).
In fact, in the 1980s, when I examined thicknesses of film for reference for camera design, there was information thatsome products of film manufacturers in the eastern Europe countries that used old equipment were thick, making it easy tosuppose that the thickness variations in the 1920s were even larger.
In the end, the truth is most likely that when the approximate 138 cm available for photo shooting after subtracting theapproximate 11 cm length of the leader part, the approximate 8 cm of the two exposures of blank feed, and the approximate
3 cm of the rear end from the 1.6 m was divided by the pitch 3.8 cm corresponding to one exposure, 36 exposures became
the standard.
It seems from a picture taken with his wife that Barnack was of small stature and probably not even 165 cm tall. Since
the arm span of a person is almost the same as his or her height, the theory is widely disseminated that Barnack pulled out
an amount for the Ur-Leica from a long roll film equivalent to his arm span in the dark room and used it, making the numberof exposures 36. In fact, I, being 165 cm tall, appreciated its easy-to-handle length when I developed 36-exposure film forthe first time myself over 40 years ago, and have always believed this theory.
The circumstances of camera development just happened to result in 36 exposures, and the fact that the length was easy
to handle in a dark room was also truly fortuitous.
The George Smith camera, which was prototyped in 1912, earlier than the Ur-Leica, using 35 mm film, was a very
complete camera, with a maximum of 100 exposures. While it is said that this camera ended with only trial production due
to insufficient funds, perhaps 36 exposures would not be the industry standard for the camera today if the George Smith had
made it to the market.
(Note 1) Kondō, Hideki. Daremo Kakanakatta Raika Monogatari [The Untold Leica Story], (Shashin Kōgyō Shuppansha, 2001), pp.89-91.

20

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

4

Development of the 35 mm Compact Precision
Camera

4.1 The Contax, Leica’s Rival

Leica's strongest rival, the Contax, is a masterpiece
produced by Zeiss Ikon. As mentioned earlier, Zeiss Ikon was
created in 1926 through the merger of four leading companies,
led by Carl Zeiss, in order to escape the post-World War I
recession. Since the Leica I came out in 1925 and the merger
occurred the following year, it is easy to conclude that Zeiss
Ikon was founded to compete with the Leica, but that is not thecase.
In fact, Zeiss did not even glance at the Leica for the firstfew years following the release of the Leica onto the worldstage. It is also clear that the masterpiece of the spring camera,
the Ikonta, was released in 1929 and gained much popularity,and the subsequent hit products of this series, such as the Baby
Ikonta and the Semi Ikonta, were launched in rapid succession
to survive the rough waves of the Great Depression. With newseries being developed one after another while consolidating
the pre-merger products of the four companies, the eccentric
Leitz compact camera was of no particular concern.
However, at about the same time as the breakthrough of the
Ikonta, the popularity of the Leica was increasing, and the“eccentric compact camera” gradually became a presence that
could not be ignored. The creator of the Contax, Heinz
Kueppenbender, was born in 1901 and joined Carl Zeiss in1927 after graduating from RWTH Aachen University. In
1929, he received his PhD in research on rotating disc shuttersfor large cameras at Stuttgart University of Applied Sciences,and was sent from Carl Zeiss to Zeiss Ikon in the same year.

Photograph 4-1

Heinz Kueppenbender1)

Kueppenbender was chosen to head the company at the
young age of 31 and, in 1941, was recalled to Carl Zeiss toserve on the Board of Directors and became the western leaderof Zeiss, which was divided into East and West divisions afterWorld War II, and thus had a reputation for excellence.
The first camera designed by Kueppenbender after moving
to Zeiss Ikon was the Contax I (the Contax when first released,
but for the sake of distinction, is now called the Type I after
the release of the Type II).

Photograph 4-2

Contax I(Provided by JCII Camera Museum)

There is a myth that the Contax I was developed as anantithesis to the Leica. Certainly, the Contax I has a strong
technical and structural contrast with the Leica, such as its
vertically traveling metal shutter curtains to Leica’s
horizontally traveling cloth shutter curtains, its removableback cover to Leica’s non-existent back cover, its focus
adjustment on the body side to Leica’s focus adjustment on thelens side, and its bayonet mount to Leica’s screw mount.
However, there seems to be a strong implication that thesedifferences are the result of Kueppenbender pursuing an ideal
compact camera, and that these features differ from those of
the Leica by chance. Of course, the Contax I had to adopt a
different structure to avoid patent infringement and certainchanges were most likely consciously made based on theidentity of the engineer, but if the Leica were nonexistent,
would the compact Contax camera made by Kueppenbender
be any different?
For example, when considering the shutter, the Leica has its
shortcomings, such as malfunctions at low temperatures due tothe stickiness of the rubberized cloth curtains in early products,
risk of pinholes when accidentally facing the sun, and longexposure time from start to end due to travel in the longitudinal
direction of the picture frame.
As a result of pondering the ideal shutter structure,
Kueppenbender most likely concluded on vertical travel andthe use of metal. Modern focal-plane shutters, while having
different structures and shapes, are constituted by rigid metal
blades that travel vertically, and so it is not impossible to saythat Kueppenbender had foresight. Yet, the main reason
behind the design of the modern shutter is unitization andsynchronized speed when using a flash device.
The Contax I represented the culmination of

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –21

Kueppenbender pursuing the ideal camera while being
cognizant of the Leica. As a result of the pursuit of the ideal,
the design was more elaborate, but Zeiss Ikon had the
production technology for mass production.
The metal curtain of the shutter is a “louver type” thatcombines thin plates of duralumin, which was the mostadvanced alloy at that time, and the body is constructed of diecast aluminum alloy silumin all the way to the back cover,making a blockbuster with as many as 650 parts. The large
number of parts can be contextualized from the fact that many
SLR cameras of later years would be constituted by less than
1,000 parts even with full additions of a mirror drive
mechanism and the like.
The Contax I was released in 1932, and the Leica II was
released in the same year followed by the Leica III in thefollowing year. The two great rivals of the 35 mm format
compact precision focal-plane shutter camera stood theirrespective grounds and, without anyone capable of following
their lead, enthusiastic camera fans watched the battle unfold
between the two strongholds with deep interest. The Japanese,in particular, who may have a national character that enjoys
lionizing confrontations between two powerful forces, such as
Tochinishiki-Wakanohana (sumo-match), Waseda-Keio(university) and Giants-Tigers, were divided into the Leica
camp and the Contax camp.
The confrontation came to the forefront in the famous 1935
Leica-Contax controversy. In the August issue of Asahi
Camera of that year, the article “Which Is Better, the Leica or
the Contax?” written under the pseudonym KKK, ignited thesmoldering Leica-Contax controversy.

4.2 Contax I Technology in the Leica-Contax
Controversy

published a brochure entitled “Furikakaru hinoko wa
harawaneba naranu” [Brushing Off the Falling Sparks] andoffered a counterargument.
The superiority or inferiority of a camera depends on thevalues of the user and the subject to be photographed, and thequality of being “beautiful in appearance” mentioned in thearticle should not be easily scored in view of the diversity ofaesthetic consciousness. However, since the scheme of thearticle itself reflects an extremely interesting point of view, in
this paper, I would like to follow this article and touch on thecharacteristics of the Contax I while comparing the Contax I
with the Leica IIIa.
The article rates twelve specifications and technologies. In
the words of the author KKK, “Criticizing superiority or
inferiority vaguely lacks clarity. Performance and other main
points were therefore separated out into twelve items, andsuperiority and inferiority were compared by a scoring method
based on a scale of 100 points, giving 100 points to the superior
camera ... “ The following considers the technical features of,among the 12 items, the shutter, rangefinder, viewfinder andlens, as well as the operation system and lens mount whichwere not among the 12 items.
4.2.1
Shutter Mechanism of the Contax I
As mentioned above, the Contax I uses a vertically traveling
focal-plane shutter made of metal. The shutter curtain is madein a louver style by combining strip-shaped duralumin toprevent light leakage, and is supported by cloth ribbons on
both sides. The structure that drives the front curtain and therear curtain independently in a retractable manner is similar tothat of the Leica.

The Asahi Camera article created a big stir. Although theauthor claimed to be fair, the fact that he was in the Contax
camp is clear since all attached examples were indoor
photographs advantageous to the Contax, and the total score
given when the cameras were rated by specification andfunction was higher for the Contax. This no doubt incensed the
Leica camp.

Photograph 4-4

Shutter of the Contax

Given the series of problems of stickiness at low
temperatures with the rubberized cloth shutter curtains in theearly days of the Leica, the use of metal made sense. However,Leica had claimed to have already solved the problem byreplacing the shutter with a better one (but honestly admitted
that the shutter had had some problems).
Photograph 4-3

Leica-Contax Controversy2)

The Leica import shop, Schmidt Shōten, responded
immediately. In March of the following year, Schmidt Shōten

22National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

The reason for changing to vertical travel is probably thedesire to shorten the travel distance more than to compete with
the Leica as mentioned above. While certainly there is ajustification in this regard, the axis of rotation of the shutter
curtain became perpendicular to the axis of rotation of thewinding knob on the front side of the camera. Therefore, inorder to transmit the rotation operation of the winding knob tocharge the shutter, right angle conversion by a bevel gear was
required. The knob on the right in Photograph 4-5 is forwinding, and there are two bevel gears on the back (left side),
the right being for shutter charge and the left being for film
winding.

camera, and it is a fact that the Leica IIIc was unavailable tothe private sector because most were for military use.
According to the book by Sanuki Matao, an aviation critic who
lived in Germany around 1940 and has a deep knowledge ofGerman cameras, Sanuki could not get the Leica IIIc in
Germany and finally bought a second-hand one in Switzerland.
When the shutter of the Contax II that he had purchased earlier
broke down, he wrote, “The plates of the shutter are made ofmetal, but cloth strings are what binds them together. It wassaid that this string is destined to break, but undoubtedly it
broke quickly due to harsh use. This is not very suitable formilitary use.”3) So, it seems that the Contax shutter was more
likely to break down than the Leica shutter and, at least for
military use, the reliability of the Leica shutter was higher.
4.2.2

Operation System

As mentioned above, the rotation axis of the Contax I
winding knob is parallel to the optical axis of the lens, but thisalso requires right-angle conversion for film winding. In otherwords, the axis of the winding knob, the winding axis of the
shutter curtain and the winding axis of the film intersect three
Photograph 4-5

times, like each axis in an XYZ space, as shown in Photograph

Structure of the Contax (1)As understood by mechanical engineers, regardless ofwhether we are talking about a camera or not, a power sourceof a rotating system transmits power more efficiently with theaxes parallel to the extent possible. This is because spur gears
can generally be designed with higher transmission efficiency
than bevel gears. While the bevel gear is also theoreticallyhighly efficient, the axes intersect, making it difficult, as apractical matter, to arrange bearings efficiently. Further, thebevel gear is exceedingly sensitive to machining accuracy andassembly accuracy, causing a drop in efficiency even with theslightest error. In view of the production technology at thattime, the rationality of the Leica, with the shutter, spool andwinding knob all designed with parallel axes, is appreciatedhere again.
However, Zeiss Ikon designed such a shutter because thecompany was confident in the high production technology formass production that supported it. Production technology anddesign level should always be considered together, and thepoint is that the shutters of the Leica and the Contax are
fundamentally different in their position in terms of thecompany, product development concept, and design concept,
and should not be easily labeled superior or inferior since thevalue judgment varies depending on the individual who uses it.
Perhaps the point that the Leica camp found mostunforgivable was that KKK rated the Contax shutter 100 points
and the Leica shutter 60 points. As for the superiority andinferiority of functions, there are advantages anddisadvantages as mentioned above, but KKK’s comment, “TheContax ..., as it stands today, appears to be without fault” issomewhat of an overreach. From the latter half of the 1930s to
wartime, the German army adopted the Leica as a military

4-6. For this reason, the power of the winding knob istransmitted to the film winding system and the shutter charge
system via a complicated transmission system, causing thepower to be extremely torqued. To begin with, the windingknob is on the front of the camera, which is not a position foreasy operation.

Photograph 4-6

Structure of the Contax (2)The reason that the winding knob is on the front is probablythat it was difficult to install with a horizontally longrangefinder provided on the upper side of the camera. The
winding knob was installed coaxially with the shutter dial. The
shutter dial was placed on the front because Kueppenbender
was contemplating installing an exposure meter in the future.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –23

Of course, it is better to place the exposure meter on the subject
side (that is, on the front side of the camera). At that time, it
was easier to link the exposure meter and the shutter dial.
Kueppenbender was convinced that the exposure meter would
be an important specification in the future, which was correct
in consideration of later camera transitions, but this windingknob was problematic with its operation surface and hightorque, and he conceded a point to the Leica, which prioritized
operability.
The Asahi Camera article makes no mention of operability.
The only item related to operability is film loading, where
Leica scores 90 points against the 100 points for Contax. The
Contax is viewed as having an advantage because the backcover can be removed, which is understandable, but the Leica
camp most likely found it hard to understand the omission ofother aspects of operability.

Figure 4-1

Drehkeil Rangefinder

There is a theory that the Contax I changed the position of
the viewfinder from the middle of the series because it violateda Leica patent, but this is incorrect. Zeiss has the right to place
the viewfinder between the left and right rangefinder windows
in Germany. Nevertheless, the Leitz patent, which was filed
about nine months behind Zeiss, was granted overseas,

4.2.3

Rangefinder and Viewfinder

including Japan, prior to Zeiss. In other words, Zeiss had

The Leica IIIc rangefinder was designed with an external

preferential rights in Germany and Leitz had preferential rights

horizontal rangefinder built into the camera, but the baseline

overseas. It is not public how the two companies resolved thislength was about 38 mm due to the arrangement of thetwisted state of affairs, but presumably they exchanged license

operation system. On the other hand, the Contax I has aagreements with each other4).

baseline length over 100 mm by fully using the width of the

The Contax drehkeil rangefinder is an exceptionally goodcamera at the beginning of its release, and 93 mm with the newrangefinder in itself, and its performance as a rangefinder

optical system installed midway through the series. The

surpasses that of the Leica. Nevertheless, the viewfinder was

accuracy of the rangefinder is determined by the effective

pushed to one corner of the camera to avoid the long bar-baseline length, which takes into account not only the baseline

shaped prism. In this regard, the Leica, making effective use

length but also the magnification and, although the Leicaof space, places the viewfinder close to the shooting lens,increased the magnification of the rangefinder midway

making it possible to reduce the distance between optical axes

through the series against the Contax, the Leica could notof the viewfinder and the shooting lens and reduce the parallax,

match the Contax.

which is a shortcoming of rangefinder cameras. The Contax

The reason that the Contax I rangefinder changed midway

had to compromise on this point. Nevertheless, with athrough the series was that it changed from the initiallytelephoto lens for which a rangefinder with a long baseline

mounted orthodox type, which has a movable mirror, to thelength is effective, the parallax problem is alleviated, making

drehkeil type, Zeiss's specialty. The drehkeil (meaning to twist

this is a strong telephoto policy. In short, this is also aa wedge) type is a combination of two wedge-shaped circulardifference in product concept, and should not be labeledlenses as shown in Figure 4-1, and the deviation angle issimply either superior or inferior.

changed by rotating each in the opposite direction. The stablestructure has more redundancy than moving a mirror and is

4.2.4

Lenses and Lens Mountresistant to shock and aging. In addition, since the rear bar-

In a sense, what made the Leica camp grit their teeth theshaped prism and the drehkeil can be separated, the drehkeil

most when the Contax I was released may have been the

can also be used for spring cameras where the lens and bodyContax lens lineup. When the Type I was released, six

are mechanically separated, and is an excellent method utilizedinterchangeable lenses were prepared. Each one was a highly

in many Zeiss cameras such as the Ikonta series. However, theacclaimed lens for posterity and showcased Carl Zeiss's opticaladoption of a bar-shaped prism made it impossible to place atechnology to its fullest. Among them, the Sonnar 50 mm F1.5

viewfinder between the left and right rangefinder windows.

boasted epoch-making brightness at that time, and the 50 mm
F2 boasted the highest F value in the focal length range, greatly
surpassing the Leica. The brightness of a lens is an
irreplaceable property and, with only low-sensitivity films at
the time, such brightness was a great advantage especiallywhen shooting indoors. It seems that there were many
photographers and enthusiasts devoted to the Contax I because

24

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchof the existence of this lens.

Leica (II-IIId) units, a figure more than double the Contax’s5),

The lens mount also was a big advantage for the Contax side,and the Leica had the marketing battle advantage in Japan aseven though, for some reason, it was not addressed in thewell. So, there was probably no need for the Leica camp to

Leica-Contax controversy. Leica screw mounts had features

aggravate the face-off after all.

such as ease of standardization, wear resistance and excellent

In any case, the development competition between the Leica

workability, and later many third-party Leica mountand the Contax was fierce, and as a result, new technologies(hereinafter “L mount”) lenses and cameras appeared, forming

were introduced with each model change, honing thethe L mount family. On the other hand, the Contax bayonet

specifications and functions. Given that it is an undeniable fact

mount was modern in terms of quick attachment/detachmentthat this rivalry contributed significantly to the development ofand easy radial positioning. In fact, the fact that Leica also

the 35 mm focal-plane shutter market, I would like to once

adopted a bayonet mount when transitioning to the Type M,

again pay tribute to the passion and talent of Barnack andand that most of the later SLR systems of each company ended

Kueppenbender, the creators, and to Leitz and Zeiss Ikon, theup using the bayonet mount format is proof of this.

companies that produced such wonderful products.

4.4 The Contax II
In contrast to the Leica, which evolved through acumulative process of frequent minor changes, the Contax
exhibited a full model change with the Type II released in 1936.
This is probably because it was necessary to improve theelaborate parts seen in the Type I and to incorporate requests
probably received from inside and outside the company.

Photograph 4-7

Lens Mount of the Contax

In the Asahi Camera article, KKK gave Leica 75 points forthe lens against Contax's 100 points, but regardless of thequantitative validity, the Leica camp had to admit that Contax
was the winnerinthe lens department.

However,photographers who do not need a bright lens may well feel thatthe score difference should not be so high. The lens also is an
aspect that depends largely on subjective values.
On the whole, clearly it is quite unreasonable to judge
everything as superior or inferior based on a quantitative score.
KKK also understood this as he wrote, “When you score thecameras based on 12 items, the result is as described above.
The scores, however, are not absolutely reflective, and theimportance of each item varies from person to person,”slinking away in the end.

4.3

Photograph 4-8

Contax II(Provided by JCII Camera Museum)First, improvements were made to the film winding knob.
The position of the film winding knob provided on the front of
the Type I was problematic in operability and, due to theinternal structure, the torque was high and the feel was not
good. The knob was moved to the upper surface of the camera,significantly enhancing the transmission efficiency andimproving the winding feel.

Achievements of the Leica

The shutter dial, which was complicated to set, was also

and the Contax

improved to a uniaxial type, that is, a type that allowed the

The Leica-Contax controversy in Japan was a mudslinging
match and, although the article by the instigator KKK cancertainly be described as somewhat unfair, the Leica campalready enjoyed a big difference in sales and perhaps shouldhave tried to look undaunted and not have made such a battle
cry.
Looking at the production volume of each from 1932 to
1945, to the Contax’s (I-III) 134,200 units, there were 317,385

shutter speed, even a low shutter speed, to be set with one dial,ahead of the Leica. While the war may partially account for it,
the Leica did not adopt the uniaxial design until the M3 in 1954,
so the Contax was a pioneer in this regard.
Furthermore, the viewfinder also improved to a single-lens
type integrated with the rangefinder, and the rangefinder alsochanged to a schwenkkeil type, which is a further
improvement of the drehkeil type. Schwenkkeil means a

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –25swinging wedge and, as shown in Figure 4-2, is a combination

retired because he was Jewish, and was replaced byof two cylindrical lenses, one of which is “swung” to change

Kueppenbender. On the other hand, Leitz also transferred

the wedge angle and alter the optical path.

many Jewish employees to Leitz New York in the UnitedStates as a humanitarian move. Despite this chaos, the compact
35 mm camera proved especially useful for military use. As acold climate specification, a special Leica IIIc military modelwith ball bearings built into the shutter drive shaft was madeand delivered to the German Air Force.
As mentioned above, most of the Leica IIIb and IIIc, except
the post-war versions, were devoted to military or government
agencies. This is because the 35 mm camera, which islightweight, durable, provided with interchangeable lenses

Figure 4-2

Schwenkkeil TypeThe design was also updated and, as indicated by thenickname Chrome Contax that set it apart from the blackpainted Type I, its appearance with beautiful chrome plating
has that camera-like look when viewed from a modern
perspective.

4.5 Compact Camera Under Wartime Regime
Occasionally I have mentioned that compact cameras
played a military role. As Nikon (Nippon Kogaku Kogyo Co.,
Ltd. at the time of establishment), which celebrated its 100th
anniversary in 2017, is well known as a Mitsubishi-affiliatedoptical weapons manufacturer that developed rangefinders forbattleships, sights for bombers and fire control systems forballistic calculation (mechanical calculators), optics and themilitary are closely linked. Various industries were deployed
for military purposes, and the optics field is no exception. Here,I will describe the trends of compact cameras under thewartime regime, which triggered the development of cameras
after World War II.
4.5.1
Military Use of Compact Precision Cameras
I think 1936 (Showa 11) was a milestone year in the long
history of the camera. Shortly before Schmidt Shōtenpublished the brochure entitled “Brushing Off...” during theLeica-Contax controversy in March of 1936, the February 26
Incident occurred and a disturbing air was beginning to drift inJapan.

depending on the situation, and known to deliver surprisingly
good images, was indispensable for reconnaissance andintelligence activities.
While, due to the nature of the matter, the 35 mm camera
was not showcased in this role, an example that supports theabove is that, in the Sorge incident in 1941, which isconsidered to be Japan's largest espionage incident, the Leicaand the Contax were found among seized goods. Richard
Sorge, the main criminal, favored the Leica, and Branko
Vukelić, who was in charge of photography, favored theContax I and II. The Type II reportedly had the Sonnar 50
mm F1.5 mounted thereon6). These 35 mm cameras werepurchased as general commercial products and did not undergo
any special modifications for espionage, providing a glimpseof their overall excellence.
4.5.2

Penetration of Compact Precision Camera into
News Media

Although not intelligence activity per se, another exampleof the 35 mm camera playing an active role in a similar
situation is the February 26 Incident. On the early dawn of
February 26, 1936, an army infantry regiment, having left the
Roppongi barracks, divided into several groups, attacked andassassinated leading officials, and subsequently occupied
various locations. Japan was shaken from the attempted coupd'etat that caused many injuries and nine deaths, including thedeaths of two ministers, but surprisingly the event in various
parts of Tokyo are recorded in a number of vivid photographs.
The rebels attacked the Asahi Shimbun and Tokyo Nichi Nichi

Overseas, Hitler became the chancellor of Germany in 1933,

Shimbun, and were also strongly hostile to a number of media

and the largest piece of propaganda, the Berlin Olympics, wasoutlets, so why were the rebel soldiers so easily photographed?

held in 1936. In that corner of Germany, Oskar Barnack

The answer lies in the compact precision camera.

embarked on his eternal journey on January 16 of the same
year. Then, as described later, the full-scale sale of the Hansa
Canon, Japan's first 35 mm focal-plane shutter camera, began
in 1936 and, in this same year, the photo magazine LIFE,
which brought about a major turning point for later Japanesecameras, debuted in the United States.
In this dark era, at Zeiss Ikon, the president, Goldberg,

26

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

The Asahi Shimbun, which detected signs of a major
incident, kept all six Leica III models at the photo-related
distribution trading company Konishiroku Honten that day,and started using them the next. Other companies perhaps also
pulled out in-house compact cameras that had been rarely useduntil then. On the other hand, when looking at this from therebel soldier side, there is the stereotype of the news
photographers at that time having a big clap camera (folding
cameras used for news at that time), and the crowd of people
wearing coats and wandering around appeared only to be thegeneral public. The rebels, first off, could not afford to makeenemies of the general public, and so could not reproach them.
They did not realize, it seems, that they were having theirphotos taken by photographers who were sticking out just the
tip of a small lens from behind their coats, and thephotographers were able to take advantage of the situation andget closer.

Photograph 4-9

limited.
If importation proved difficult, domestic production was the
only answer, and so each country sought to produce a 35 mm
compact camera by respective methods. The result? The birthof a large number of Leica copies.
The term Leica copy is now common, but its definition is
ambiguous. This is because, even given the definition that
Leica copy is a rangefinder camera that uses 35 mm film, isequipped with a focal-plane shutter, and is similar in exterior
design to the Leica, to what degree the design is similar or not
is a subjective assessment.
I have two books, “LEICA COPIES” and “300 Leica
copies.” If you look at the number of models, the former lists
about 230, and the latter lists about 300 as the title suggests, so
you can see that the number depends on the definition. For
example, each model of Nikon manufacture, which is a typicalrangefinder camera in Japan, is not listed in the former but islisted in the latter. This is because the former defined a Leica
copy as having a “lens mount compatible with that of the
Leica,” therefore removed a Nikon camera that had a Leica
type shutter but a lens mount conforming to (but notcompletely compatible with) that of the Contax.

Asahi Shimbun Relaying February 26
Incident7)

In this way, a number of powerful, compelling photographs
coupled with scenes of unmelted snow that had fallen on thecity a few day earlier made their debut, and represent a turning
point for the news media as they realized the usefulness of thecompact camera.

4.6 Leica Copy GenreWith the gradual recognition that the 35 mm compact
camera is suitable for various activities under the wartime
regime, the demand in the military and national institutions ofeach country increased. On the other hand, production
restrictions also increased, making it difficult to increase thenumber of shipments. In Germany, although domestic sales
were secured with priority, the hostile Allies put a halt toimporting the excellent German camera.
Japan also entered a state of war starting with the Marco
Polo Bridge Incident in 1937, and the Trade and Related
Industry Coordination Law and the Temporary Measures Law
on Imports and Exports were proclaimed in August and
September, respectively. This made it difficult to import
cameras from abroad for virtually non-military purposes. Even
securing the required import quantities for military purposes
was difficult due to geographical problems and, while there
seemed to be a back route via Manchuria, the quantity was

Photograph 4-10

Leica Copy Reference Books

In any case, it is surprising that so many Leica copies were
produced in countries all over the world. Among thesecountries, Japan enthusiastically produced many copies. Somewere made for military purposes in a manner close to national
policy, while others were made out of personal passion. One
thing that can be said is that the development of the compact
precision camera, whatever the purpose, attracted the hearts of
the Japanese people. The national character reflected in thequest, playfulness and hand dexterity in the creation ofelaborate mechanical dolls may have constituted a perfectprerequisite for the embrace of a compact precision camerathat requires minimal resources and materials and has
reasonable hobby-like characteristics that satisfy the joy of
personal ownership.
Above all, the Leica served as a great exemplar. Whendisassembling the Leica, the hobbyist is charmed by its direct
simplicity and cannot help but feel that, even for him, it may
be easy to make. The Contax, however, does not even begin tostir a feeling of wanting to make a dead copy to thatcomplexity; it would actually be impossible. This is the reason
why, compared to the abundant number of Leica copies,

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –27

Contax copies are virtually non-existent.
4.6.1

Leica Copies Made in the United States

In this section, I will take a momentary sidestep away fromthe topic of Japanese Leica copies and briefly touch on thesituation of the 35 mm compact camera in the United Statesand, in the next section, in the Soviet Union.
When the importation of the Leica ceased, there was a
movement to develop a Leica type camera in the United States.
New York Leitz, the US base of Leitz, actively cooperated
with the US military and, unusual for its national character thatemphasizes originality and dislikes imitation, developed the
Kardon, a Leica copy. With a late start, the Kardon was
actually delivered to the military in 1943, but this camera isvery well made and showcases the industrial strength of theUnited States at the time. The Kardon also included, as acomplete military model, a model called the Military Kardon
which featured a larger winding knob and the like to improve
operability when wearing gloves and is now a collector's item
due to the limited number produced.

Photograph 4-11

Military Kardon

Photograph 4-12

Ektra

(Provided by JCII Camera Museum)4.6.2
Leica Copies Made in the Soviet Union
The Soviet Union was a country that produced Leica copies
much earlier than Japan. Since there was no partner company
such as New York Leitz in the United States and the country
was completely hostile to Germany, the Soviet Union ignored
patent rights and proceeded to produce dead copies.
The FED has many variations as Leica copies, but reportedly
its first trial was completed in 1932. Then, in 1934, mass
production of the FED, almost a perfect copy of the Leica II,
began. FED is an acronym for Felix Edmundovich
Dzerzhinsky, the founder of the KGB. These cameras wereapparently used for both civilian and military purposes. The
FED brand copies were conscientious replicas, some evenwith the Leica stamp, resulting in the speculation that they
were made on a national scale to earn foreign currency. Many
Soviet Leica copies, such as the FED and the subsequent
Zorki, were manufactured for a long time after the collapse of
the Soviet Union, and many remain in the used camera
market to this day.

(Provided by JCII Camera Museum)

In connection with the development of the compact 35 mm
camera in the United States, the Kodak Ektra deserves to bementioned, although it is not a copy. Kodak, being a film
manufacturer, had felt that the camera need only be a tool that
consumes film, that is, a tool having the bare minimum fortaking photographs, and hence produced products that were afar cry from a camera designed as a precision machine. Yet, in
1941, Kodak, out of the blue, released the Ektra. This camera

Zorki

was equipped with epoch-making specifications and functions,

Leica copies are thought to have been produced in almost

such as a rangefinder with a long baseline length, a zoom

all countries that had even the slightest experience in camera

finder, and film back replacement, and partly outperformed the

manufacture, and yet, upon closer observation, reveal the

Leica and the Contax. The Ektra was the result of Kodak

particular national character and national strengths of eachtapping into its technical capabilities while making reference

country, making them very interesting as a research theme onto the German camera, but was a failure that sold only about

technological cultures.

2,500 units in eight years. It was much larger and heavier thanthe Contax. The Ektra was a concrete example of the fact thatthe philosophy that performance matters most, regardless ofheaviness and length - as was the case with American cars in
the past - did not apply at all to the camera.

28

Photograph 4-13

(Provided by JCII Camera Museum)

4.7 Leica Copies and Development ofCompact Precision Cameras in Japan
Many Leica copies emerged in Japan as well. The definitionof a Leica copy is ambiguous, but herein a Leica copy isdefined as a 35 mm film-compatible camera equipped with a
focal-plane shutter, provided with a Leica-like internal layout

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchand exterior design, and capable of lens interchange. In thissection, we will consider the background, technical featuresand subsequent developments of each manufacturer.
4.7.1

Precision Optical Instruments Laboratory(Currently Canon)
While I have emphasized that the main purpose of a Leica
copy was military use, the first Leica copy in Japan, the Hansa
Canon, was not for military use, and there is some resistanceto lumping it together with the other copies.
Yoshida Gorō, who had a career in repairing motion picture
cameras, came up with the idea of developing a camera when
his business partner in Shanghai told him that if Japan can
produce such excellent battleships, there is no reason why
Japan cannot make its own cameras. An experienced camera
repairman, looking at a disassembled Leica, would most likely
believe that he could do it himself. Yoshida immediately
brought in his brother-in-law, Uchida Saburō, who worked fora securities company, and established Precision Optical
Instruments Laboratory (later Japan Precision Optical
Instruments Laboratory, Precision Optical Industry, Co., Ltd.,
Canon Camera Co., Ltd., and now Canon Inc., hereinafterreferred to as Precision Optical), and starting producing
mockups and various prototypes. An advertisement using a
mockup appeared in an issue of Asahi Camera at that time.
Yoshida's enthusiasm inspired in Shanghai is evident in theadvertisement, “The best submarine is the I-go. The best
airplane is the Army Type 92. The best camera is the Kwanon.
They are all the best in the world.” Yoshida made detailedadvances with the Kwanon in the Takekawaya Building near
the Roppongi Intersection, but development did not progress
as expected. A camera such as the Leica looks easy to make,but in fact is not.

Photograph 4-14

Kwanon Camera Advertisement8)

There is an interesting story. On the west side of the
Roppongi Intersection, near what is now Tokyo Midtown,
there was a barracks for the Army Infantry Regiment. Captain
Yamaguchi Ichitarō, who was there, was ideologically close to
Captain Andō Teruzō, the mastermind of the February 26
Incident, and allowed the removal of firearms and bullets fromthe warehouse on the day of the incident. Yamaguchi was abright light in the field of optical equipment and, in Matsumoto
Seichō’s exploration into Showa history, it is stated,“Yamaguchi was quite an engineer in measurement
instruments that measure the impact distance of guns, and hecontributed to a number of developments in coincidence-type
rangefinders. That is why he had contact with Nippon Kogaku,
Nippon Kokan, Kayaba Manufacturing, etc., and ... seems tohave earned a bit of pocket money.”9)
In addition, it seems that he was also in and out of Precision
Optical, which was a few minutes' walk away, and his
autographed resume states, “In 1935, ... I personally provided
guidance for Canon, which established a research institute in
Roppongi.” Further, it seems that he also pursued a rubberized
cloth curtain for Konishiroku’s aerial cameras10).
While the details are unknown, there are signs that showthat military personnel proficient in technology moved behindthe scenes between companies, eventually complementing
each other's technical and material shortfalls, which lead to thedevelopment of the Japanese optical industry. There is asimilar story about the mounting of the Nikkor lens in earlyPrecision Optical cameras.
Kwanon, the brand in the advertisement, is named after
Yoshida's Kannon faith. In addition, the advertisement states“Kasyapa” as the lens name, which is also a religious namederived from Buddha's disciple Mahākassapa. Reportedly,
because either the eccentricity of Yoshida was not in line withthat of Uchida or Yamaguchi or he was suspected (yet falsely
accused) of unaccounted-for expenditures, Yoshida left the
research institute less than a year after the institute wasestablished. Looking at overseas documents, one document
describes Yoshida as the catalyst of Canon. Since the term
catalyst means inspirator, it is indeed strange to say that therole of Yoshida was to encourage others and trigger
development.
Although Yoshida's camera was modeled after the Leica, it
seems to be the result of pursuing his idealized form rather thansimply making a Leica copy. Adopting a brand name reflecting
one’s faith perhaps implies that he held some sort of belief inthe technical aspects as well. However, he had a tendency topursue the ideal to an excessive degree.
Looking at the advertisement in Asahi Camera and thesketches of the prototype that Yoshida drew based on his
memory in his later years, there is one in which the windingknob is placed on the front of the camera following the Contax
I. However, in Japan at that time, it was not possible to achieveprecision part machining at the level of Zeiss, and successremained elusive. It seems that Uchida completely corrected
the trajectory after Yoshida’s departure, and although thecamera gradually came to resemble the Leica, the fact that afilm counter was placed in front was novel. Uchida also
wanted to bring out originality.
Speaking of originality of Precision Optical, there is theshape of the camera when viewed from above. The Leica has
an oval shape and the Contax has a rectangular shape, but

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –29

Precision Optical used an octagon to differentiate the camera
from others. This octagonal design has long been used in later
Canon cameras and is a distinctive exterior feature.
What Uchida had trouble with were the rangefinder andviewfinder. Even if he could manage to achieve themechanical design, the more specialized optical design was outof reach. The solution to the dilemma came in the form of apartnership with Nippon Kogaku. Uchida consulted with his
second oldest brother, who was a supervisor there, about
optical design. At that time, Nippon Kogaku was amanufacturer of optical weapons for suppliers to the Navy, andalthough it seemed strange to lend a hand to consumer cameras,
the company was interested in and enthusiastic about
consumer products that would enjoy a stable demand.
In any case, a good prospect for optical design was found.
The scope of intellectual property rights of Leitz for its utility
model of “placing the viewfinder between the two windows of
the rangefinder” was very wide, and designers had a hard time
avoiding it, but Uchida came up with a tricky “jack-in-the-box”
solution in which the viewfinder pops up at the time of use.
Compared to the subsequent Leotax which avoided the patentrights by shortening the baseline length, resulting in asignificant loss in ranging performance, the camera was muchsmarter. A utility model for this “jack-in-the-box” is registeredwith Uchida named as the inventor.
The mechanism of the coupled rangefinder, similar to thatof the Contax, rotates the distance ring of the lens from thecamera side, and seems to have been designed by Yamanaka
Eiichi at Nippon Kogaku, as the utility model (Registration No.
229211) was registered under his name11). Due to the adoptionof this coupled rangefinder, the mount was unique, differingfrom the Leica, but was changed to the L mount in successor
models after the war. Perhaps it would have been moreadvantageous to make a universal Leica-compatible camera.
The decision was made that Nippon Kogaku would also
supply standard lenses and that Omiya Shashin Yohin(currently Hansa Co., Ltd.), which enjoyed huge sales
channels for photographic supplies, would be the dealer. In thefall of 1935, more than a year after the camera was advertisedin Asahi Camera, its release was finally officially announced.
This camera was the Hansa Canon, Japan's first 35 mm
compact precision camera with a focal-plane shutter. The
Hansa is a brand name of Omiya Shashin Yohin and it was
equipped with the Nikkor 50 mm F3.5 of Nippon Kogaku as astandard lens. The form crowned by each of the three major
brands still in existence today - the Canon, the Nikkor and theHansa - is spectacular even to this day and, as a camera thatmakes full use of each company’s specialty, is fitting as Japan's
first 35 mm camera with a focal-plane shutter.
The selling price was either 270 yen or 275 yen, dependingon the literature, but the difference of five yen seems to bewhether or not the sales staff received a commission.

30

Photograph 4-15

Hansa Canon(Provided by Canon Camera Museum)

Although there is evidence that a small number were sold in
1935, full-scale sales began in early 1936. The beginning of1936, as you recall, was the time of the February 26 Incident.
In connection with this, there was an episode that showcases
the scale of Precision Optical at that time. In the early days of
the incident, a part of the infantry regiment that left the Army
garrison made a left turn at the Roppongi Intersection where
Precision Optical was located, and headed for Nagatacho
where the Prime Minister’s Office was located. Uchida and hiscolleagues, frightened by the unusual atmosphere, decided toevacuate, gathered together the work-in-progress and otherparts of the camera, which amounted to only two wicker trunks,
and were able to escape immediately. Even though this wasjust after the release of the first domestically produced 35 mm
rangefinder camera, that was all they had.
The Hansa Canon was a product that brilliantly shined in
the history of the Japanese camera industry and was highly
praised at that time, but productivity became a problem as the
Sino-Japanese War bogged down into a stalemate. The
cameras relied on Nippon Kogaku for the coupled rangefinders,lenses and mounts, but Nippon Kogaku began to prioritize
munitions products, leaving little room for the consumer
camera. Among the cameras, in 1939, Canon’s standard type(also called Type S), popular type (also called Type J), newstandard type and popular type with a slow shutter werecommercialized in small numbers, and this small-scale
production of consumer cameras led to success after the end of
the war.
When Japan entered the Pacific War, the country had nochoice but to focus on the production of munitions products.
According to company history, the company produced
binoculars, range meters and the like12), and most likely thesewere requested by Nippon Kogaku. The range meter was the
Army’s term for the Navy’s rangefinder, and is mounted on atank or the like to measure the distance to the target.
In March 1944, Nippon Kogaku formed the Japan OpticalIndustry Corporate, an organization of 108 partnercompanies13), and there is information indicating that thedirector general was Precision Optical14).
Precision Optical temporarily dissolved in the burnt fields
immediately after the end of the war, but revived with 156
employees on October 1 and, even in the midst of scarce
supplies immediately after the end of the war, collected parts
from before and during the war, and launched production
quickly, bringing a total of about 500 postwar popular type(Type JII) cameras to the market15). Then, in the fall of 1946,
the newly designed SII was released, which became theblockbuster that led to the company’s rebirth.
Precision Optical got this far with the cooperation of

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchNippon Kogaku in personnel transfers, equipment transfers
and the like, but in the years after the war, developed their own
lens, Serenar, ridding themselves of dependence. Even after
being hit by the “M3 Shock” later, the company continued todevelop and improve the rangefinder camera and, having
released various models through the latter half of the 1960s, isthe authority with regard to the rangefinder camera equippedwith a 35 mm focal-plane shutter in Japan.
The Hansa Canon, which is not an L-mount, is, at the very
least, not a Leica dead copy, and its originality is largely
evident. This originality is what draws the line between the
Hansa Canon and dead copies such as the Leotax, the Nicca
and the Melcon described later, and it seems that the early
independent spirit of this camera is what led to later
development. In a sense, it is truly moving to think that the
maker, in a small room with two wicker trunks of work-inprogress at the time of the camera’s launch, is now a corporate
giant with annual sales of about 4 trillion yen.
4.7.2

Kyōei-sha (later Showa Kōgaku, Showa
Optical Works Ltd., Leotax Camera)
With the ambition to make a 35 mm film camera after
learning about the Leica, several engineers left Rokuosha, thecamera manufacturing division of the long-establishedphotographic supplies company Konishi Honten, and created
Kyōei-sha in 1938. Minagawa Shōten, which was amanufacturer of First brand cameras, and San-ei-sha, a sales
company, invested in it, and a sales channel was establishedthrough Misuzu Shōkai (later Misuzu Sangyō), a major
photographic supplies sales company. Well aware of the
difficulty of obtaining German products and the success of the
Hansa Canon, the manufacturing and sales departments, seeing
the future of the 35 mm camera, had an intense, passionatebond.
The company name was changed to Showa Kogaku
immediately, and the Leotax original was released thefollowing year. The Leotax was the second domestically
produced 35 mm compact precision camera with a focal-plane
shutter following the Hansa Canon. With the brand name being
a compound word combining Leica and Contax and theexterior design being virtually identical to that of the Leica II,
the camera lacks the originality of the Hansa Canon. Theinternal structure is almost a dead copy of the Leica, but therangefinder and the viewfinder periphery are different from theLeica. In order to avoid the utility model intellectual property
rights of Leitz, the viewfinder had to be placed outside the left
and right rangefinder windows instead of between them. For
this reason, the baseline length was inevitably extremely short.
Even the Leica's 38 mm was short, so 27 mm, which is about
30% shorter, was problematic in terms of performance.

Photograph 4-16 Leotax (Original)(Provided by JCII Camera Museum)In addition, the rangefinder was a stand-alone type that did
not couple with the lens distance ring, and so was not as usefulas that of the Leica. Thinking about it now, perhaps a little
more ingenuity was required in the utility model workaround.
Priority was given to achieving an exterior appearance like theLeica, but in doing so essential performance was sacrificed.
Still, Leotax products were relatively good in other respects
and sold reasonably well, so the company was able to release
improved models one after another. In 1942, when therangefinder-coupled Special A and the Leica utility model
became available after the war, Showa Optical made a goodshowing with the release of the Special DII and Special DIII,
which boast a performance close to that of the Leica. The factthat the cameras were equipped with Simlar and Topcor lenses
made by Tokyo Optical was also highly praised. Like Nippon
Kogaku, Tokyo Optical was an optical weapons manufacturer
with close ties to the military, and also worked extensively on
camera lenses.
Leotax continued to make constant model changes andstood shoulder to shoulder with other rangefinder cameras, but
after the 1954 “M3 Shock,” was unable to switch to a SLR
camera like other manufacturers, broke away from the Leica
copies, and bet on the Leotax G, which featured a design closer
to the M3. This model was well thought out and developed,
and had the potential to be the first step in recovery. However,
because the company had stopped production of products
made to date and at the same time focused its efforts on thisnew product alone, it didn’t manage to survive even as far as
the date of release. At last, the subcontractors were able tohand over the parts and the assembled products were released,
but it was too late and Leotax's good fortune completely ran
out. The final product, the Leotax G, is ironically unbelievably
valuable in the current collector's market, partly due to the low
production volume.
4.7.3

Kōgaku Seikisha (Optical Precision Instrument
Company)
Precision Optical, which set sail on the compact precision
camera ocean with the Hansa Canon, left the cramped
Roppongi quarters four months after the February 26 Incident
and moved to a new factory in Meguro, where production
continued and developed steadily. By 1938, the number of
employees, which was less than 10 at the time of its founding,

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –31

had increased to nearly 100. From there, a few engineers withaspirations founded the spinoff Kōgaku Seikisha (later
absorbed by Yashica via Nippon Camera, Nicca, and Taiho
Optical) in 1940. From the company name (meaning “Optical
Precision Instrument Company” in English), one gets a senseof the motivation and ambition of the founders, believing thatthey too could make a similar camera.
Initially, the company worked on remodeling the Leica anddomestic cameras, but then decided to make a Leica copy
based on an offer from the military, which was suffering fromdifficulty in obtaining compact cameras. As mentioned above,
the United States started developing the Leica dead copy called
the Kardon for the same reason, so Japan and the United States
faced the same situation, craving the Leica in the face of the
Pacific War. In that sense, in contrast to the Kardon whose
commercialization was delayed in 1943 despite its high quality,
the technology of Kōgaku Seikisha, which was easily
commercialized in 1942 (although an imitation), is quite
skillful. It was also a big deal that the company was allowed toignore the Leica utility model with the approval of the military.
The result of this effort was the Nippon. In the UK, there is aremarkably high quality Leica dead copy called the Reid. The
Reid was produced in the UK based on drawings of the Leicathat the British army requisitioned after the war due to thedifficulty in obtaining the Leica, but took more than three years
to complete and, when compared to the Reid, the ease ofhandling of Kōgaku Seikisha’s product stands out.

In 1959, the company changed its name to Taiho Opticaland became a subsidiary of Yashica as a mid-sized camera
manufacturer, and soon was completely absorbed and merged.
Yashica was founded as Yashima Seiki in 1949 and, in 1953,
changed its name to Yashima Kōgaku Seiki. and started
mainly producing the 6 x 6 format camera. Almost at the sametime as the merger of Nicca, Yashica also incorporated Zunow
Opt., which developed an advanced single-lens reflex camera,
and strengthened its technological capabilities for the compact
precision camera. As a 35 mm focal-plane camera, the last
Leica copy of the Nicca brand (copy of the Leica M3), theNicca IIIL, was released in 1958, and the same model was
released as the Yashica YF the following year. This camera isa rare model that features both the Yashica and Nicca logos.
Yashica's specialty was mainly compact cameras with lens
shutters, and the company subsequently achieved ablockbuster hit with the Yashica Electro 35 series and also
entered into production of popular price range SLR cameras.
In the 1970s, the Contax RTS, an ultra-luxury SLR camera that
revived the Contax brand in partnership with Carl Zeiss,suddenly appeared on the market, astonishing the world.
However, due to the failure of new business and the oil crisis,business deteriorated, and the company was absorbed by andmerged with Kyocera at a humiliating share ratio of 1:13. Afterthe Nippon camera, which started from a Leica dead copy,
finally reached, through twists and turns, Leica’s rival, theContax brand, what was it that caused the company toultimately withdraw from the camera market? An explanationof SLR cameras, such as the Contax RTS, will be given in alater chapter.
4.7.4

Photograph 4-17

Nippon(Provided by JCII Camera Museum)

The Nippon was immediately delivered to the military. The
number delivered is said to be about 300, and apparently somewere installed in the night fighter, the Gekkō (Moonlight)16).
Considering that there was no leakage of information related
to complaints from the military, most likely the Nippon wasused as a substitute for the Leica without much problem.
After the war, the Nippon was launched as a consumer
camera under the Nicca (abbreviation for Nippon Camera)brand. The company name was changed to Nicca Camera in1950, and the Nikkor lens supplied by Nippon Kogaku wasmade their standard, causing the company to be relatively wellreceived. Focusing on exports, the company expanded its sales
channels and made cameras for Sears Roebuck under the
Tower brand, Peerless under the Peerless brand, and Australia
under the Snider brand, but could not escape the Leica deadcopy impression and gradually business deteriorated.

32

Nippon Kogaku Kogyo Co., Ltd. (currently
Nikon Corporation)
There is considerable resistance to classifying Nippon
Kogaku as a Leica copy manufacturer. This is because the lensinterchange is almost compatible with the Contax, not the
Leica, and the exterior design is similar to that of the Contax
II. However, features such as the shutter structure and layout
are similar to those of the Leica, so it can be said that it is a“best of both worlds” camera.
Nippon Kogaku was founded in 1917 by Mitsubishi

Zaibatsu who, sensing the need for an optical weapons
manufacturer, merged a part of Iwaki Glass and a part ofTokyo Keiki Company, and immediately after that, Fujii Lens
Manufacturing. In line with its stated reason for being, thecompany was engaged in the production of military optical
weapons such as periscopes and rangefinders until the end of
the war, but after the end of the war, the number of employees,
which had been as many as about 25,000 until then, wasreduced to 1,724 and the company made a fresh start17). A
camera was one of the candidates for advancement into
consumer products. Initially, priority was given to the twinlens reflex camera, but development of the lens shutter did not
go well and so resources were concentrated on the 35 mm

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchfocal-plane camera. Thus, in 1948, the Nikon I (the originalframes to 38 mm, which is the same as the Leica, whilename was the Nikon Camera, but later was changed to thechanging the picture size to 24 x 34 mm.

Nikon I to distinguish it from its successor) was released. Even

The Nikon M was internally treated as a corrected drawing

Nippon Kogaku, which boasted some of the most advanced

version of the Type I, and came to be called the Type M later

technologies in military optical weapons, struggled withby adding the letter M to the serial number for distinction.

consumer products, and the camera was released after a

Furthermore, the same camera with a synchro terminal added

difficult delivery due to schedule delays and quality problems.

was released in late 1950 and was called the Type S.

Photograph 4-18

Nikon I

Photograph 4-19

(Provided by JCII Camera Museum)

Nikon S

(Provided by JCII Camera Museum)

The Nikon I is equipped with a horizontal focal-plane
shutter similar to the Leica, but the lens mount used is theContax bayonet type. The reason for this is that, from before
the war when the lens was delivered to Precision Optical toafter the war when the lens was delivered to Nicca, there wassome reluctance to make a camera that used the same L-mountlens.
Although the company had experience in camera lens
production, the Nikon I, the first compact consumer camera
from Nippon Kogaku, exhibited originality in its internalmechanism that makes the camera not just a copy, adopted aball bearing for the shutter bearing, and incorporated ingenuity
such as coaxially arranging the shutter speed setting dials forhigh speed and low speed, which are separately arranged on
the top and front of the camera on the Leica, on the top of thecamera. In addition, the picture size is 24 x 32 mm, the socalled Japanese format. The Nikon I was not the first to adopt
the Japanese format. The format was adopted earlier incameras such as the Minolta 35I, the lens shutter camera the
Olympus 35, and the Mignon of Tokyo Optical, and was seenin overseas cameras as well. However, there is no evidence ofuse of the Japanese format being planned together among thecompanies. The Nikon I is the result of selection of an aspectratio that felt well-balanced, and it seems that the company
considered this 3:4 ratio as more suitable for humansensibilities than the Leica's 2:3 and prioritized the economic
efficiency of taking 40 pictures.
However, because this Japanese format did not match theautomatic cutter for slides, complaints were made by the US
military stationed in Japan, and thus, in the next Nikon M, thecompany was compelled to correct the pitch between picture

In the same year, photojournalist David Douglas Duncan,
who was sent to Japan to shoot antique art by LIFE magazine,
was surprised at the sharpness of a photo taken of him by hiscolleague, Miki Jun, at his office in Tokyo and learned about
the excellence of the Nikkor lens. The Korean War broke out
on June 25, and Duncan flew to the Korean Peninsula with two
Leica IIICs and a Nikkor 50 mm F1.5 and a Nikkor 135 mm
F4 converted to L mounts. Also, a few days later, LIFE
magazine photojournalist Carl Mydans headed to the Korean
Peninsula with the Contax and a Nikkor in hand.
Hank Walker, who took the place of Duncan, headed for the
frigid Korean Peninsula with the Nikon M. While othercameras stopped working, the Nikon M seemed to workwithout fault. The excellence of these Nikon cameras andNikkor lenses became a hot topic in a New York Times article
published on December 10 of the same year. The number of
Nikon cameras sold increased about five-fold from 2,533 in1950 to 12,873 in 195318).
The Nikon S got on track and gained confidence as well as
development investment, and full improvements were realized
in its successor, the S2. The S2 camera was to be the first
Nikon to have a picture size of 24 x 36 mm, and a system was
set up to pursue the Leica in earnest, but the innovative Leica
M3 was released in April 1954, just before the release of theS2, causing confusion in urgent improvement work anddelaying the release until the end of the year. The
improvements made were reportedly to the winding lever, therewinding knob and the viewfinder magnification, but were
not made public.
The features of the S2 include the 24 x 36 mm size, a onetime winding lever (the Leica M3 is a two-time winding lever),

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –33

a crank-type rewinding knob, an equal-magnification albadatype viewfinder with a bright frame, a high speed shutter timeof 1/1000 second and an aluminum die-cast body (until then it
was a sand molding). The S2 is a camera having extremely
good balance in terms of performance, quality and price, andbecame a best-selling rangefinder camera of Nikon.
Nippon Kogaku subsequently released the S3, the S4 andthe SP. The SP released in 1957 boasted the highest
performance among the Nikon rangefinder cameras, and iscomparable to the Leica M3 with its universal viewfinder that
supports lenses with six focal lengths and an evenly spaced
uniaxial non-rotating shutter dial. Nevertheless, at this time,
the Contax S, a SLR camera with a pentaprism, and the
Asahiflex, Japan's first 35 mm SLR camera, were alreadyavailable, and the design and development team of Nippon
Kogaku was strongly aware of the SLR camera.
4.7.5
Chiyoda Kogaku Seiko Co., Ltd.
Chiyoda Kogaku Seiko was founded in 1928 as Nichi-Doku
Shashinki Shoten (Japan-Germany Camera Company), waslater renamed through Mechanismus Optik und Linsen vonTashima (MOLTA) and, in 1947, shortly after the war,
released the Minolta 35I, a 35 mm focal-plane camera. Thiscamera is considered to be the fourth Leica copy in Japan andis listed in the previous two Leica copy books, but hasoriginality and personality that set it apart from a simple Leica
copy. The designer was the company's Miyabe Hajimu, whoused the Leica before the war, identified its strengths andweaknesses, and developed the camera based on the designconcept of “More is luxury, less is out of the question.”

Photograph 4-20

Minolta 35I(Provided by JCII Camera Museum)and is an excellent mechanism that has been adopted in many
SLR cameras since then. The concept appears to be one of
reducing the horizontal width of the camera and prioritizing
the miniaturization in the horizontal direction as well as
adoption of the Japanese format.
The company also showcased its ingenuity in the way thefilm is loaded, and adopted a hinged back cover that is neither
the Leica bottom lid type nor the Contax back cover removable
type. This method was also advanced as evident from the factthat it was subsequently adopted in most cameras.
Chiyoda Kogaku Seiko manufactured 6 x 4.5 format
cameras before the war and released products in a wide rangeof fields such as twin-lens reflex cameras and lens shuttersafter the war, expanded into single-lens reflex cameras in 1958,
was renamed Minolta Camera in 1962, and grew into one ofJapan's leading SLR manufacturers. Yet, it seems that its
ingenious development capabilities originated with the
Minolta 35I.
It should be noted that Miyabe subsequently transferred to
Mamiya Optical and demonstrated his talents in, for example,
making a prototype Prismflex equipped with a pentaprism, andlater worked as a professor at Chiba Institute of Technology
and developed camera-related standards.
4.7.6
Other Manufacturers
After World War II ended, many Leica copies came to themarket. This was because after Germany’s defeat all German
patents related to cameras and the like became available basedon the Berlin Declaration. As a result, the 35 mm cartridge film
became widespread, expanding the user base, and, above all,cameras offered a large margin of added value to resources andmany found it incredibly attractive that, with little skill andknowledge, it was possible to make a reasonably profitableproduct with small-scale equipment and minimal materials.
The Leica copy brands in Japan, in a broad sense, are listed
below, each with a brief explanation. The phrase “in a broad
sense” encompasses cameras that use 35 mm film, are lensinterchangeable, equipped with a focal-plane shutter andprovided with a rangefinder, and have an overall design similar
to that of the Leica. These descriptions hopefully convey theenthusiasm and vibrancy of the camera engineers who longed
for the Leica and desperately pursued it in the short period
immediately after the war, even though the manufacturers
were not up to the standard of those described in the previous
section.

As you can see in the picture, the Minolta 35I is different
from the Leica in terms of appearance. As for the mechanisms
as well, the specifications are a bit different from the Leica,
including adoption of the Japanese format, installation of aself-timer, adoption of a single-lens finder (the rangefinder andthe viewfinder for composition share the same window), a
unique design called “Umebachi (a plum blossom crest) type”
of the lens distance ring, a 4-axis focal shutter, a 45 mm F2.8
as the standard lens and a synchro contact on the accessory
shoe. The 4-axis shutter replaced the thick shaft on the feeding
side, which is the basic form of the Leica, with two thin shafts,

34

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

(1)The Melcon(3)

The Melcon is a Leica copy released by Meguro Kōgaku
Kōgyō in 1955. It is almost a dead copy of the Leica, but ischaracterized by a back cover that opens and closes. The
Nikkor was mounted on the Melcon, making the Melcon quite
popular. While it seems that the mounting of the Nikkor
stemmed from the sales company of the Melcon being thesame “Hinomaruya” as the Nicca, the camera apparently
caused a complaint from Nippon Kogaku. From the successor,
the Melcon II, the Leica copy was eliminated and the camera
became a Nikon S2 copy, but the mount remained the L mountinstead of the Nikon S mount. Meguro Kōgaku Kōgyō
continued production until 1958, but went bankrupt due to ashortage of capital and its lack of prowess from a technicalpoint of view.

Photograph 4-21

MelconThe Chiyoca/Chiyotax

The Chiyoca 35 was released in 1951, which is relatively
early compared to other Leica copies, and is the only Leica
Standard (a popular version of the Leica II with the rangefinder
removed) copy in Japan. This camera was made by Reise
Kōgaku (later Reise Camera) and sold by the trading company
Chiyoda Shōkai. Note that Chiyoda Shōkai has nothing to dowith Chiyoda Kogaku Seiko Co., Ltd., mentioned above. Afterreleasing several successors, including Leica II copies, for its
Leica III copies the company changed the brand name to
Chiyotax IIF. This is because Chiyoda Kogaku Seikoregistered the name of Chiyoca as a trademark, so the namecould no longer be used. The Chiyotax IIIF included a modelwith the Hexar 50 mm F1.9 lens from Konishi Honten.
Unable to increase production scale and with thewithdrawal of Chiyoda Shōkai midway through development,
Reise Camera released the product leaving the brand name asis. Subsequently, in 1957, the Alta was released that was
remarkably similar to the Chiyotax IIIF, but it is said that the
major trading company Misuzu Shōkai acquired Reise Camera,
renamed it Misuzu Kōgaku Kōgyō, and released the cameras
under a new brand19). The attached lens, the Altanon 50 mm
F2, is similar to the Tanar 50 mm F2 made by Tanaka Opticalmentioned above, so it seems that this lens was also made bysimply changing the brand name.

(Provided by JCII Camera Museum)(2)

The Tanack

The Tanack is a Leica copy sold by Tanaka Optical since
1953, a company that made motion picture lenses, Leica
accessories and the like. Although the camera is almost a deadcopy, the back cover opens and closes like the Melcon. The
Tanack featured its own lens brand, the Tanar, and continued
to release successor models to 1959. The company showed its
ambition, particularly in the later period, with its release of the
Tanack 35 V3, featuring a change from the L mount to an
original bayonet mount, but apparently ran into a lack of
capital as lenses for that mount were never released, causing
the camera to require attachment of an L mount lens via an
adapter. Subsequently, the VP, which reverted back to the L
mount, was the last model.

Photograph 4-22

Tanack IIC(Provided by JCII Camera Museum)

Photograph 4-23

Chiyoca IIF(Provided by JCII Camera Museum)(4)

The Ichicon, Honor and Jeicy

Only a small number of cameras with the Ichicon, Honor
and Jeicy brand names remain in the current used camera
market, and the details of these cameras are not wellunderstood. The singularly famous book “Maboroshi no
Kamera wo Otte [Chasing the Phantom Camera]” left by Shirai
Tatsuo has an interesting description of an interview with
Kumagai Genji, the founder of Kōgaku Seikisha, and isreferenced herein.
Kumagai, the designer of the Nippon Camera, resigned
from Nicca in 1948 and made a new prototype of a Leica copy
called Jeicy, featuring a back cover that opens and closes. This
was the Ichicon 35 which was brought to Dai-ichi Kogaku andmass-produced, and continued production with Zenobia
Optical, which was rebuilt after Dai-ichi Kogaku collapsed,
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –35

but later collapsed as well. The Honor was made and released
by Mejiro Kōgaku based on the Ichicon 35 without notifying
Kumagai20).
Subsequently, the Honor brand seems to have changed
hands from Mejiro Kōgaku to Zuiho Optical. The SL, the final
model of the Honor, was not a Barnack Leica copy but rather
a design that imitated the Canon. The camera had no major
features in terms of specifications and was eventually
withdrawn.

Japanese factories.
However, even if such parts were blindly copied, it is adefinite fact that the production technology and processing
technology of the unknown subcontractors in Japan at that time,
who made parts virtually identical to the parts shown to themin a short period of time, satisfied the minimum requirements.
An interesting phenomenon is that, despite excellent copies
being made in the United States and Europe, there was almost
no subsequent development taking advantage of the copies, yet
the camera industry in Japan, after the war, developed
dramatically based on the technology gained from making theLeica copies. In Europe and the United States, where
originality is more valued, manufacturers had no choice but to
get involved in producing copies as an emergency measure in
the war effort, whereas Japanese people, who were always
encouraged to “steal art” from their masters, did not feel much
resistance to imitation. In addition, rather than being businesslike, it was probably fun to disregard profitability and makesomething for its own sake.

Photograph 4-24

Ichicon 35(Provided by JCII Camera Museum)(5)

The Simor, Murey and Motoca

Other Leica copies such as the Simor, Murey and Motoca
are known to have existed, but little is known about them. The
only thing that can be said is that these cameras were decent
Leica copies, perhaps not at all junk, even if the origins are
unknown. At this distance in time, we can only sense that
unknown engineers, passionate about the camera, wereabsorbed in imitating the Leica without any funds or sales
channels, as if possessed by something, and so there existed
professionals working in the light of recognition as well as
laymen and enthusiasts making their energetic contributions inthe shadows in the Japanese tradition of craftsmanship.
4.7.7
Analysis of the Rise of Leica Copies in Japan
Allow me to repeat myself a bit. While the Leotax as wellas the Nippon are dead copies, the technology for making
reasonably high quality products in a short period of time canbe said to be unique to Japan, and I think that is significant. In
the United States and the United Kingdom, even to make acopy, the manufacturer seems to have gone through a series offormal processes, including disassembling the Leica, startingfrom an investigation of each mechanism and a detailed
investigation of each part, subsequently creating the drawings,
building a prototype to check the quality, and then entering
mass production. In, Japan, however, there were factories that,
if one just brought to them original parts and asked them toduplicate them, they would do it without a lot of fuss, and thatwas that. There is a technique called “matching” in progressive
press working, which leaves recesses unrelated to function on
the outer circumference of a part, and there are amusing stories
relating that even these recesses were blindly copied by36

By nature, Japanese people are flexible in thinking andtechnical ability, and are able to handle everything dexterously,
so following an original was not so difficult. Nevertheless, it
is also a fact that further development could not be achieved
without some strengths such as novelty and originality being
involved during the pursuit. As described later, the moment
Japan felt it had caught up, the innovative Leica M3 wasreleased, which proved to be a turning point in the Japanesecamera industry. After this, many Leica type and Leica copy
manufacturers were forced to drop out, and only threecompanies, Canon, Minolta and Nippon Kogaku, survived.
The technology of Nicca, narrowly incorporated by Yashica,
remained, but was not much different from Leotax, which wentbankrupt due to the absorption-type merger.
The three companies had originality and financial strength.
It can be seen that, for the Leotax, the Nicca and the Tanack,the companies tried to plan a product with originality andchanged their minds after seeing the M3. A full model change
required huge development costs, however, and the companies
got bogged down due to cash flow issues. Perhaps thecompanies could have been saved if they had proceeded down
their own individual paths as early as possible, but theyrecognized the change in the situation too late.
Darwin said, “It is not the strongest of the species thatsurvives, nor the most intelligent that survives. It is the one thatis most adaptable to change,” and when we look at the dawnof development of the compact precision camera in Japan, werecall those words.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

4.8 Growing Reputation of the Japan-Made
Camera and Background
After the war, Precision Optical, which was the first to
launch a consumer camera, completed the J developed before
the war as the JII, and released the SII in the fall of 1946. From
the SII, the original mount of the Hansa Canon was changed to
the L mount, offering the practical advantage of usability withthe many Leica lenses available on the market.

lenses and cameras were also highly praised by the
publications in LIFE magazine and the New York Times, andhelped raise the level of the Japanese camera industry as awhole. The Japanese-made camera that was thought to be in
the realm of imitation was now in the spotlight.
The domestic economy was also boosted by the special
demand brought on by the Korean War from 1950. This isbecause, when people have leisure time to enjoy things, theytend to be attracted to hobby-like diversions, such as
photographs. Figure 4-3 shows the sales performance of Canonand Nikon cameras during this period. The figure shows thatthe number of sales increased significantly every year.
Sales Performance Trends

Photograph 4-25

Canon SII

(Provided by Canon Camera Museum)

Cameras of the Canon brand, which got off to a flying start
after the war and boasted stable camera quality, were
extremely popular among the US military stationed in Japan.
Precision Optical changed its name to Canon Camera(hereinafter referred to as Canon) in September 1947, and thereason for this changes is that, for the Americans who came intheir jeeps directly to the factory to purchase the camera, theCanon name proved much easier to remember than Precision
Optical21).
Following Canon, which skyrocketed to the top of the 35
mm focal-plane cameras after the war, was Chiyoda Kogaku
Seiko Co., Ltd., who entered the 35 mm focal-plane market
with the Minolta 35I in 1957. Then, Nicca and Leotax
followed, who had been working on Leica copies since the war.
I have already mentioned that Nippon Kogaku underwent alarge-scale restructuring immediately after the war ended, but
one of the reasons that the camera industry started up fasterthan any other industry immediately after the war ended was,I believe, that many camera engineers and workers flowedfrom Nippon Kogaku to other camera companies. Then,
Nippon Kogaku, with a slight delay, continued with the Nikon
I in 1948, and quickly released the improved M version. I thinksuch a movement after the war is due to the structure peculiar
to the camera industry, which somehow can manage withtechnology even if resources and materials are scarce.
The Japanese government spared no effort to back up the
production of these compact precision cameras in Japan. Thisis because sales to the US military stationed in Japan wereregarded as exports, even though they were domestic, andcould contribute to the acquisition of foreign currency as
collateral for imported food products.
Canon launched the IIB as a successor to the SII in 1949,
and won first prize at a national camera exhibition held in San
Francisco in the fall of the same year. The following year, thecamera was exhibited at the first international trade fair in
Chicago and was well received. As mentioned above, Nikon

Figure 4-3 Trends in Post-War Sales Performance ofCanon and Nikon Cameras22)

On the other hand, domestic cameras with quality problems
began to emerge and, from January 1949, the Japanese
government decided to apply the Act Concerning Control ofExport Commodities to cameras as well, and inspection ofcameras for export became obligatory. New JES (JapaneseEngineering Standard) 7101 and 7102 were used as inspection
criteria. These new JES standards were based on the inspection
rules for exported cameras, which were drafted by the Officeof Control Association for Precision Tools in 1943 during the
war and prepared by the Camera Subcommittee of the Opticaland Precision Instruments Manufacturers' Association after thewar. JES is the predecessor of the current JIS (JapaneseIndustrial Standards).
This exported product inspection was taken over by theJapan Camera Inspection Institute (later, Japan Camera &Optical Instruments Inspection and Testing Institute (JCII))
established in 1954 with Moriyama Kinji, a member of theDiet, as the chairman, and became a method for professional
inspection by a third party. Until then, self-inspections andsubcommittee inspections were the main types of inspections.
This exportation inspection by JCII was carried out over a long
period until December 1989, and greatly contributed to themaintenance and improvement of the quality of exported
cameras. Note that the current JCII has shifted the focus of its
business to cultural projects and, while the abbreviation
remains JCII, the institute, as the Japan Camera Industry
Institute, manages the JCII Camera Museum, the JCII Photo
Salon and the JCII Library under the supervision of the wife ofMoriyama Kinji and the former Chief Cabinet Secretary,Moriyama Mayumi.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –37

References and citations
1) Hans-Jürgen Kuc. Kontakkusu no Subete [On the Trail of
the Contax], (Katsumido Shashinkiten, 1993), p.24.
2) Schmidt Shōten. “Furikakaru hinoko wa harawanebanaranu” [Brushing Off the Falling Sparks] and Asahi
Camera, August, 1935.
3) Sanuki, Matao. Doitsu Kamera no Hon [Book on theGerman Camera], (Shogakukan, 1998), pp.9-13.
4) Kurashikku Kamera Senka No. 76 [All about Historical
Cameras No. 76], (Asahi Sonorama, 2005), pp.72-76.
5) Sakai, Shūichi. Raika to Sono Jidai [The Leica and its
Era], (Asahi Shimbun Publications, 2000), pp.188-189.
6) Ogura, Iwao. Kamera to Sensō [The Camera and War],(The Asahi Shimbun, 1994), pp.61-62.
7) Asahi Shimbun, February 28, 1936, Tokyo evening
edition, first page.
8) Asahi Camera, August 1934, (The Asahi Shimbun), A22.
9) Matsumoto, Seichō. Shōwashi Hakkutsu 6 [Unearthing
Showa History 6], (Bungeishunju, 2005), p.356.
10) Ogura, Iwao. Kamera to Sensō [The Camera and War],
pp.52-55.
11) Arakawa, Tatsuhiko. Sōgyō [The Foundation], (Asahi
Sonorama, 1986), pp.27-29.
12) Canon Inc., Kiyanonshi: Gijutsu to Seihin [Canon
History - 50 Years of Technology and Products], (Canon
Inc.), pp.21-22.
13) Nikon Corporation, Hikari to Mikuro to Tomoni – Nikon

38

75-nen-shi [Light and Micro Together: A 75-year History
of Nikon], (Nikon Corp., 1993), p.90.
14) Arakawa, Tatsuhiko. Fukkoku Akarui Anbako [(Reprint)
The Bright Dark Box], (Asahi Sonorama, 2000), p.50.
15) Katsumido Shashinkiten, Kiyanon Renji Faindā Kamera[Canon Rangefinder Camera] (Katsumido Shashinkiten /Asahi Sonorama, 1996), pp.54-55.
16) Shirai, Tatsuo. Maboroshi no Kamera wo Otte [Chasing
the Phantom Camera], (Asahi Sonorama, 1982), p.19, 25.
17) Nikon Corporation, Hikari to Mikuro to Tomoni – Nikon
75-nen-shi [Light and Micro Together: A 75-year History
of Nikon], p.100.
18) Nikon Corporation, Hikari to Mikuro to Tomoni – Nikon
75-nen-shi [Light and Micro Together: A 75-year History
of Nikon], p.139.
19) Leica Copies by HPR (CCP).
20) Shirai, Tatsuo. Maboroshi no Kamera wo Otte [Chasing
the Phantom Camera], pp.25-26.
21) Katsumido Shashinkiten, Kiyanon Renji Faindā Kamera[Canon Rangefinder Camera], p.61.
22) Katsumido Shashinkiten / Asahi Sonorama, Kiyanon
Renji Faindā Kamera [Canon Rangefinder Camera], p.72;
Hikari to Mikuro to Tomoni – Nikon 75-nen-shi [Lightand Micro Together: A 75-year History of Nikon], p.139.
(Graphics by author)

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March5

From Leica Copies to SLRs

5.1 The Impact of the Leica M3

Recently, it was announced that Photokina, the world's

largest photo trade fair in Cologne, Germany, that has been
held in the fall of even-numbered years will now be held every
spring, starting from 2019. Photokina in 1954, which dates
back 65 years from 2019, was also held in the spring, and on
April 3, the first day of the event, the Leica M3 took the stage,
which was a major turning point in the history of the camera.
Leitz removed itself from the 35 mm focal-plane camera trail
it had blazed with the Leica IIIf and introduced a completely
new system.

First, the bright frame-type field frame indicating theshooting range is automatically switched in accordance withthe focal length of the lens. A bright frame is a white field
frame that emerges clearly by skillfully combining multiple
thin plates so that only the field frame portion of light can passthrough a dedicated lighting window, and overlaps the subject
image. The conventional field frame is simply vapor-deposited
directly onto the viewfinder lens, and was sometimes difficult
to see, depending on the viewing angle.
As shown in Figure 5-1, the bright frame-type field frame isa beautifully translucent white frame automatically selected inaccordance with the focal length when any of the three typesof 50 mm, 90 mm and 135 mm lenses released at the same time
was attached (the outermost frame for 50 mm was always
visible).

Photograph 5-1

Leica M3

(Provided by JCII Camera Museum)However, Japanese camera manufacturers had a notablepenchant for finding out information in advance, and thenumber of persons making the trip to Photokina were more

Figure 5-1 Finder of the Leica M3than usual, including some who, without visiting other exhibits,

The finder optical system itself is a sight to see, and because

purchased the M3 released upon its announcement, and

it is 0.91x, which is close to equal magnification, the subject

immediately returned to Japan. The fact that such persons

can be captured in an image close to the naked eye. Further,

prepared enough foreign currency to immediately buy an

the finder image can be seen directly with the right eye and theexpensive camera indicates that they had acquired information

subject can be seen directly with the left eye, which is ideal forin advance.

snapshots that often involve quick shooting.

While the round shape on the left and right gives tribute to

However, the Leica is not the founder of the bright frame

the Barnack Leica, the camera has a modern and sophisticatedfinder itself. In 1947, the Duflex, the world's first SLR camera

design, beautiful chrome plating and a large viewfinder,

equipped with a Porro prism-type eye-level finder, had acausing the viewer to catch his breath just by looking at it, andwindow-type bright frame finder. The Leica development

yet, when disassembled, reveals a series of even moreteam may not have known about the Duflex, as it was produced

astonishing things. Many of the functions and capabilities ofin only a small number in Hungary, but the Casca II, launchedthe Leica M3 are introduced below.

in 1948 in the same country of Germany, had a manually
selectable bright frame finder.

5.1.1

FinderIn fact, the window-type bright frame itself had been used

In the Barnack Leica, the rangefinder and the viewfinder,

in the Kontur finder for a long time. The Kontur finder is aused for composition confirmation, were separated. While asomewhat primitive finder that allows you to look at a brightmethod of incorporating the rangefinder within the viewfinder,

frame with one eye and look directly at the subject with thereferred to as single-lens type already debuted in the Contax IIother eye, combining both images in the brain to obtain aand the Minolta 35I, Leica also realized this in the M3.

“subject image with a frame.” The Leica development teamHowever, the Leica M3 took it even further.

aimed to integrate the principle of this Kontur finder into thefinder with a built-in rangefinder, and that was exactly what it
History of Cement Manufacturing Technology

39

was.

features established the standard for later models.

Left eyeCombinedin brain

Right eyePhotograph 5-2

Figure 5-2 Principle behind Kontur Finder

Even though the finder was already by far the best, the teamadded the parallax automatic correction function. One of the
weaknesses of the rangefinder camera was the increase inparallax at short distances. Because the optical axis of theshooting lens and the viewfinder are far apart, when the
distance to the subject is short, the shooting range and the
viewfinder frame do not match. However, the Leica M3 reads
the distance information at the rear end of the lens and corrects
the parallax frame position and, by doing so, eliminates theparallax. This is Leica's striking move to create a superior
product through the skillful combination of conventional
technologies.

5.1.3

M3 Shutter Dial1)

Bayonet Mount

The 26-thread/inch fine-threaded L-mount used in the
Barnack Leica was used in many rangefinders andinterchangeable lenses. The combination of pitch and diameter
is not in the ISO standard for unified fine threads, but it is easy
to make because it is a standard thread with an apex angle of
60 degrees. There was even a third party who changed the pitchof 0.979 mm to an easy-to-make 1 mm metric screw system.
Nevertheless, since it is a screw type, it takes time tomount and is difficult to position in the radial direction
during mounting. Further, as the number of bright lenses
increased, vignetting was a concern. In order to solve these
problems in one stroke, M3 adopted a bayonet mount called
the M mount.
Changing the mount is risky considering compatibility with

5.1.2

Uniaxial Non-Rotating Shutter Dial

One of the drawbacks of the Barnack Leica shutter was thatthe shutter dial rotated while the shutter was operating. This isbecause, as described above, the pin that unlocks the rearcurtain works with the shutter dial. Another drawback is thatthe high-speed shutter and the low-speed shutter setting dials
are separated, in a so-called biaxial format. This was because
the Leica was developed by adding a low-speed shutter
mechanism to the early models that had only high-speed
shutters.
In order to solve these two drawbacks simultaneously, theconventional interchangeable lenses, but Leitz decided that
continued development of the screw type was not desirable. It
is in the spirit of the conscientiousness of the Leica that theflange back is slightly shortened so that the L mount lens could
be used with a conversion adapter.
With this, the difficulty when changing the lens, which wasa drawback of the Barnack Leica, was eliminated, making it
now possible to compete against the Contax mount and Nikon
S mount. With the leap of the M-type Leica, the M mountsubsequently became the standard mount, and many thirdparty interchangeable lenses have been produced to date.

M3 was redesigned from scratch so that there was no rotation
during operation (non-rotating) and the camera could be set
from high speed to low speed with a single shutter dial
(uniaxial), thereby achieving a shutter-setting mechanism
called a uniaxial non-rotating dial.
Considering the design of the entire camera, the short but
simple and easy-to-operate shutter dial featured the shutter
speed scale on the shutter dial arranged at equal angles, andallowed the shutter speed to be set in the middle of scale

Photograph 5-3

M3 Bayonet2)

markers. Furthermore, notches are provided on the uppersurface of the dial so that when a removable selenium type
exposure meter is attached, an appropriate exposure value canbe found in conjunction with the shutter dial. All of these40

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March5.1.4

Operability

The film winding was changed from the knob type used toreleased.

date to the winding lever type. The winding lever was found in
earlier cameras, but the M3's was easy to operate and completein design. Initially, when the camera was released, it required
two operations, but was improved to one operation midway
through the series. The shutter release button was installed
coaxially with the winding lever. This is Barnack's favorite
layout, even a Leica tradition, one could say. Looking at theM3 from above, the design, which incorporates modernization

Photograph 5-4

while retaining remnants of the Barnack Leica, is not at all
obsolete even after more than 60 years.
The first thing you notice upon touching this camera is theextreme smooth feel of the winding lever and shutter dial, andyour sensibility is tickled every time you operate them. In
subsequent film cameras, the major goal was to bring thewinding feel closer to that of the M3.
The film loading, which was a disadvantage of the Barnack
Leica, involved the same loading method from the bottom
cover side, but now was much easier than before with a portionof the back cover that opened and closed.
5.1.5

Leica IIIg

(Provided by JCII Camera Museum)The IIIg is equipped with the bright frame finder andparallax automatic correction that were successful in the M3.
The clever marketing strategy that sold the M series and the
Barnack Leica together for a long time until 1970 and held thehearts of old and new fans serves as a great reference eventoday.
5.1.6

Postwar Zeiss Ikon Trends

I would like to touch on the post-war trends of Zeiss Ikon,
who gave birth to Leica's strong rival, the Contax. When the
US military occupied the city of Wetzlar, home to Leitz, thecity amicably welcomed the occupation. For this reason, theLeica M3 Marketing Strategy

The exterior finish of the M3 is also wonderful, and thebeauty of the chrome plating is reminiscent of traditional craft.
The camera was available with a black body as well, althoughproduced in smaller numbers. The philosophy of offering both
chrome and black options became a marketing strategy that
influenced subsequent cameras.
Even after the product was released, the company remained
vigilant and continued to make small modifications,effectively driving up market demand. Leitz added manualswitching of the field frame, changed the winding lever tosingle operation, and changed the sequence of the shutter
speeds from the international series of 1,2,5,10 ... to themultiple series of 1,2,4,8,15 ... and so on. These minor
improvements were favorably accepted as Leitz' intention to
strive ever closer to perfection and, at the same time, createdcollectible value. The Leica was strictly managed in terms of
product numbers, bolstering its value. Even today, the Leica’s
mystique still generates topics of interest to camera enthusiasts,
such as the quiet fad of searching for the Leica of one’s birthyear, which is a great achievement of the Leica.
On the other hand, there were certainly some conservatives
who could not keep up with the innovations of the M3, andsome disliked the M3 becoming somewhat bigger and heavier
than the Barnack Leica. This, however, was already factored
into Leitz’ strategy, and countermeasures were considered inadvance. In the same year that the M3 was released, the selftimer was built into the IIIf, and subsequently the improved
IIIg and the low-priced version Ig were simultaneously

Leica remained substantially intact, could start production
shortly after the war and, although there were some problems
with the quality of the arranged parts, sales of the post-war
version of the Leica IIIc resumed in the fall of 1945.
On the other hand, Carl Zeiss and Zeiss Ikon awaited harshfates. The first to invade Dresden was the US military, butsince the region was to be governed by the Soviet Union, theUS military, wanting the best optical technology in the world,
secured executives and senior engineers and transferred themto Heidenheim and Oberkochen under US military jurisdiction,
which was the limit amidst the pressure of the time.
The facilities and personnel of Carl Zeiss left behind in East
Germany were requisitioned by the Soviet Army who turned
up later. Zeiss Ikon, in charge of camera manufacture, waseven more disastrous. The company was integrated with othermanufacturers in Dresden and turned into a Volkseigener
Betrieb (VEB) (Publicly Owned Enterprise). Naturally,
motivation did not rise and, in the afterglow of prewar
technology, the company finally released the world's firstpentaprism-equipped SLR camera, the Contax S. While laterthe camera division only was separated and released a
Pentacon brand SLR, the sales routes to wealthy Westerncountries were limited.
In addition, the Soviet Union, intending to manufacture
cameras in the country, sent Zeiss Group engineers along withequipment and some jigs and tools necessary for production to
Kiev, Ukraine, and resumed production of the Contax II and
III. The components of the cameras were Contax, but the brandchanged to Kiev and the cameras were named the Kiev II and
III. This series of the Kiev brand continued with the IIa, IIIa,

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –41

IV and V, but was produced by inertia until the late 1970s in aclosed socialist regime behind the Iron Curtain, with only a
few minor improvements. Yet, because the basic design wasgood, many of these “Kiev Contax” are of decent quality,
which is rare for the Soviet Union.

only with these two models. This is because Zeiss Ikon shifted
its focus to the development of the SLR camera. The result of
this shift was the Contaflex, which was released in 1953. Thiscamera, however, as described later, was equipped with a lens
shutter and lacked potential. Further, in 1960, the Contarex
series equipped with a focal-plane shutter was fully released,
but the price was abnormally high. Zeiss Ikon could not win
the battle with the SLR camera made in Japan and, after awhile, withdrew from camera manufacture. The fact that that
final decision was made by the former Contax I project leader,
Kueppenbender, who was now the president, is a quirk ofhistory.

Photograph 5-5

Kiev II(Provided by JCII Camera Museum)Of the Zeiss Group transferred to the West by the US

The Contax brand would later be revived with thecooperation of Yashica, the details of which will be describedlater. In addition, the Zeiss Ikon name was revived in 2005 as

military, Zeiss Ikon secured a camera production site at thea rangefinder camera in partnership with Cosina of Japan, butformer Contessa factory in Stuttgart, but had to leave its

there was no successor and ended with only one sister camera

excellent workers in East Germany and so the productionin the popular price range.

launch was delayed. While the Leica IIIc resumed productionin the fall of the year the war ended, Zeiss Ikon did not resume
full-scale production until 1948, and this production also
focused on the spring camera.
In 1950, Zeiss Ikon finally released the 35 mm camera witha focal-plane shutter as the Contax IIa and the Contax IIIa,
which were improved versions of the II and III, respectively.
This is the year that the Leica masterpiece, the IIIf, hit themarket.
Although late, these improved Contax versions werecameras that made up for the weaknesses of the previous
Contax cameras to date. First, the camera was smaller and

5.2 Swell to the SLR Camera
1954, when the M3 was announced, marked nine years
since the end of the war and, for the Japanese camera
manufacturer who had gotten an early start, brought an
opportunity to solidify its position with the special demand of
the Korean War and the support of the government. Canon
relocated to the current Shimomaruko, Ota-ku, and was about
to release the IV Sb2, a brush-up version of the famous IV Sb,
which was said to be on par with the Leica IIIf, while

NipponKogaku was to release the newly developed Nikon S2. The

lighter. The width is 135 mm, which is almost the same as that

Nicca and the Leotax also secured certain positions as Leicaof the Leica IIIf, and the weight is 690 g, which is 30 g lighter

alternatives as the quality stabilized.

than before the improvements, making it not the same but theDuring this period, the photography culture spread throughcloser to weight of the Leica IIIf, 530 g. Further, the layout of

the general public due to the economic upturn, and the number

the rangefinder window and the focus adjustment dial wasof cameras in the popular price range other than the 35 mm

changed at the expense of a baseline length of 95 mm to 75

focal-plane camera was rapidly increasing in Japan. As

mm, but avoided the drawback of the II, where the finger
covered the rangefinder window when adjusting the focus.

mentioned above, since the legendary “Ginza San-ai Building
Queue Affair” by Ricohflex III in 1950, TLR cameras boomed,
and many camera manufacturers jumped into the race. The
spring camera was also still actively used.
It was under such circumstances that the Leica M3 wasunleashed. At first glance, it was clear that the sophisticateddesign and advanced features surpassed even the Barnack
Leica, which had reigned at the top of rangefinder cameras.
And, to everyone’s surprise, Leitz not only announced the M3,

Photograph 5-6

Contax IIa(Provided by JCII Camera Museum)However, the Contax was a good rival of the Leica really42

but released it at that very same time. This is amazing
considering that taking several months to release a productafter its announcement is only natural, and in some cases, inconsideration of the recent digital camera situation, a camera

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March5.2.1

may never even get released after being announced.
However, it was those involved with camera manufacturers
who were shocked by the appearance of the M3, and its debut
may have seemed fantasy-like to the general public. Originally,
the Leica and the imitation 35 mm focal-plane cameras were
luxuries and out of reach unless you were a professional or aphoto enthusiast-of-means. Looking at the prices of thecameras at that time, the domestic Leica types (Nikon S,
Canon IV Sb, etc.) were 60,000 to 80,000 yen, but the TLR
camera was around 20,000 yen, depending on the attached lens,and the Ricohflex III, which caught the hearts of the generalpublic, was less than one-third of that, which was a significant
difference.
However, even if existent in another dimension, it is naturalthat camera enthusiasts of the Leica (at least its copy) would

Features of SLR for Rangefinder Camera

One of the advantages of the SLR camera over therangefinder

camera

is

that

the

SLR

is

strongintelephotography and close-up photography, as mentioned
above. The SLR camera allows you to observe the image ofthe shooting lens as is on the finder, making it possible toeasily take pictures even if attached to a microscope or an
astronomical telescope, to put it to extremes.
While this is not impossible with a rangefinder camera, it isexceedingly difficult. For example, Leica accessories include
a mirror housing with the brand name Visoflex, and Nikon also
has something similar. This housing, like an SLR, reflects theimage of a telephoto lens by a mirror placed in the middle,
allowing the user to check the focus by observing the image,but its weakness is its lack of mobility.

one day become interested in a camera that uses 35 mm film
and, looking at this time period from a holistic view, 35 mm
cameras became the mainstream in place of the mediumformat cameras and were divided into SLR cameras andpopular compact cameras.
Figure 5-3 illustrates changes in the number of domestic
cameras produced by model. In the 1950s, the spring cameras
and TLR cameras were the mainstream, but subsequently SLR
and compact cameras using a lens shutter rapidly became
widespread as 35 mm cameras. Below, I will delve into the
upsurge of the era of the 35 mm SLR camera from various
aspects.

Photograph 5-7

Visoflex(Provided by JCII Camera Museum)
Change in Number of Cameras Produced inJapan by Model
35 lens shutter
35 SLR
SpringNo. produced (1,000 units)

35 rangefinder
TLR

Year

Figure 5-3 Change in Number of Cameras
Produced in Japan by Model3)

It is very difficult to take a close-up shot at an extremely
close distance to a subject using a rangefinder, but an SLR
camera allows you to easily take such photos as long as you
have a close-up lens, or even just by placing an ordinary loupe
in front of the lens.
In other words, the SLR camera offered an extremely
versatile systematic design, and the catch phrase, “From eyesto the moon,” of the first domestically produced 35 mm SLR
camera, the Asahiflex, and the catch phrase, “From outer space
to bacteria” used when Olympus announced the M-1 later
clearly reflect this. The SLR camera was, so to speak, a childof the times who was able to successfully ride on the current
trend of seeking expansion of the imaging range.
Yet, on the other hand, there are many drawbacks unique tothe SLR camera. First, when the finder image is observed andthe shooting operation is started, it is necessary to retract themirror at the observation position and transfer the optical pathof the shooting lens to the film. Hence, a phenomenon in which
the finder becomes pitch black and the image cannot be
observed (a so-called blackout) occurs. This is a problem thatis difficult to avoid, in principle, and the mirror must be raised
prior to the shutter operation and returned to the original
position after the exposure is completed. In particular, in orderto shorten the blackout time, a quick return mirror mechanismthat automatically and instantly returns the mirror immediately
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –43

after the end of exposure is required.
In order to forcibly avoid this problem, there were somecameras that secured the semi-transparent pellicle mirror inplace and left some light on the viewfinder side even during
shooting, but the amount of light for shooting was insufficient,and thus such cameras were not widely used for generalphotography, but mainly used as special cameras for highspeed photography.
Next, there is the problem of open aperture. When shooting,the aperture of the lens is set to the desired value according to
the desired shooting parameters, but in order to confirm theviewfinder image, the aperture should be set to the maximum
until just before the shutter is activated. This is because abright image is required to correctly observe the finder image.
Accordingly, normally it is ideal that the open aperture value
is set to a predetermined aperture value only during shooting.
In the case of a rangefinder camera, the viewfinder for
observation and the lens for photography are completely
different optical systems, so problems are not likely to occur.
In addition, the necessity of this open aperture causes a
problem when measuring the brightness of the subject. Since
the aperture value is different during observation and shooting,it is necessary to transmit the difference between the open
aperture value of the shooting lens and the aperture value atthe time of shooting to the camera side in advance whenmeasuring the light in advance. This full aperture metering
method has aspects that make it quite difficult for an SLR
camera that is premised on interchangeable lenses. There isalso an aperture metering method that actually stops down theaperture of the lens to perform metering, but a detailed
explanation will be given in a later chapter, and here we will
only introduce the terms “full aperture metering” and “stopdown metering.”
There is also the problem of supporting wide-angle lenses.
In a rangefinder camera, in principle, there is only a thin focalplane shutter between the shooting lens and the film surface,
but with an SLR camera, the rear end of the lens cannot bephysically brought close to the film surface because a mirror
is inserted between them. For this reason, it is not possible toadopt a symmetrical wide-angle optical system in which lensgroups are arranged substantially symmetrically about the
principal point of the lens, such as, for example, the Topogon
type optical system shown in Figure 5-4.

Figure 5-4 Optical System of Topogon Type
Wide Angle Lens

optical system is suitable for an SLR camera with a mirror
because the back focus can be lengthened even with a wideangle lens. An example is illustrated in Figure 5-5. A concave
lens is placed in the front for divergence, making it possible tomove the convex lens group in the rear forward and gain theback focus. Compared to a normal single lens indicated by thetwo-dot chain line, the distance from the rear end of the lens to
the film surface is lengthened from L’ to L, and a single-lensreflex mirror can be placed in this space.

Figure 5-5 Optical System of Retrofocus Type

However, even today when we can take advantage of thedevelopments of optical design technology with computerbased ray tracing, this optical system is still large compared tothat of the rangefinder camera. While this point posed extreme
difficulty, just to find a way to eliminate the shortcomings of
the SLR camera had significant value.
Although the SLR camera had several shortcomings as
described above, the great promise the camera held inexpanding the imaging range to various fields was
irreplaceable. For the companies in Japan, the Leica, which
had been considered a fellow competitor in the race, was now
clearly way out in front with its debut of the M3, making
companies decide, as a practical matter, to head in a different
direction from the Leica and continue to expand theadvantages of the SLR and overcome its shortcomings.
5.2.2
Roads to the SLR
Naturally, it is easy to imagine that those in the industry who
traveled from Japan to Photokina and purchased the M3 inGermany conducted a disassembly survey within eachdepartment upon their return to Japan. At the very least, there
are records indicating that the newly established Japan Camera
Industry Association obtained the camera and allocated to eachcompany part of the task of analyzing its mechanisms andperformance.
The general theory is that the companies marveled at theinnovative spirit of the M3 and changed their direction fromthe rangefinder camera to the SLR camera at once, but there
are differences with regard to the circumstances and methods
between the companies. First, let's classify the roads taken
after the M3, focusing on each company that bloomed as an
SLR camera manufacturer later. The company names written
here are those from around 1954, the year that the M3 wasannounced.

In the 1930s, an optical system called retrofocus (meaning
to shift the focus backwards, also called inverted telephoto)
was invented, and it was indeed fortunate timing for the SLR
camera that in 1951 Angénieux (France) put retrofocus into
practical use in a 28 mm F3.5 lens for Exakta mounts. This

44

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March(1) From Leica type to SLR
Manufacturers that switched from a Leica type, that is, a 35mm focal-plane camera, to an SLR camera include Nippon
Kogaku, Canon and Chiyoda Kogaku Seiko. Nicca Camera(later absorbed by Yashica via Taiho Optical) is also
considered to have taken this route, although the circumstances
are somewhat complicated. This transition was not possible forShowa Optical Works (later Leotax Camera), Tanaka Optical,
Meguro Kōgaku and many other small-capital Leica copy
manufacturers.
Leica type cameras are basically equipped with a focalplane shutter, and the shift to an SLR camera, which is morecompatible with a focal-plane shutter than a lens shutter, waseasy to some extent, at least from the viewpoint of the shutter.
However, the development of the mirror drive mechanism andfinder optical system, which are the core of SLR camera,
demands enormous development costs and technicalcapabilities, so it was not possible to survive without adequate
financial resources and technical capabilities evincing someoriginality.

and now Ricoh Imaging; hereinafter Asahi Optical) and, eventhough digital is now the mainstream, the Pentax brandcontinues to shine.

(2) From Non-Leica type to SLR
There are many camera manufacturers that switched from a
non-Leica type, such as a 35 mm lens shutter camera and a
TLR camera, to the SLR camera. Olympus Optical Co., Ltd.,
Konishiroku, Tokyo Optical, Mamiya Optical, Fuji Photo Film,
Kuribayashi Camera, Riken Optical, Sanshin Kōgaku Kōgyō,etc., to name a few.
While it was easy for each company to unitize themechanical parts of the 35 mm lens shutter camera, the TLR
camera and the spring camera and primarily introduce lens
shutters made by shutter manufacturers such as Seikosha and
Copal to produce their cameras, these manufacturers decided
to enter the market in anticipation of the future of the SLR
camera. As a result, these manufacturers, although entering themarket at different times, succeeded in developing the focalplane shutter SLR camera. Among them, the respective speedsof the technological development of Tokyo Optical, which
released Topcon R in 1957 ahead of Nippon Kogaku andCanon, and Kuribayashi Camera, which announced Petri Pentain 1959, are noteworthy.
The relatively large manufacturers listed above were able tooffset development costs for the SLR camera through sales
from other areas of business and types of camera, but on theother hand, many of those in the camera “cottage makers” did
not have the resources to meet the prohibitive development
costs, were unable to transit to the SLR camera, and thus weredestined to withdraw or disappear.

Looking back from a global perspective, however, its(3) First-time market entry with SLR camera
A few manufacturers aimed at the SLR camera from thestart without paying attention to the development of Leica
copies and cameras of other genres. A representative example
is Asahi Optical Co., Ltd. (founded as Asahi Optical Joint
Stock Co., later Asahi Optical Co., Ltd., Pentax, HOYA, etc.

As evident in Photograph 5-8, the Sport has a strange

In addition, Orion Seiki Sangyō Y.K. (later Orion camera,
Miranda Camera) known for mass production of Japan's firstpentaprism-equipped SLR camera, and Teikoku Kōgaku
Kōgyō (later Zunow Opt.), which developed Japan's first SLR
camera equipped with an open aperture mechanism, were alsooriented toward SLR cameras from the start, but havedisappeared.
These two manufacturers should be praised for theirforesight and high aspirations in ascertaining the future of the
SLR camera, but are examples that demonstrate the difficultyof tapping into the SLR market, which requires a high degreeof systematic design and quality.

5.2.3

Pioneers of 35 mm SLR Cameras

In Japan, all 35 mm SLRs except the Asahiflex in 1952 werereleased after the introduction of the Leica M3 in 1954.
appearance was seen even before the war. Here, I will describe
the emergence and initial trends of these 35 mm SLR cameras.
(1) The Sport and the Kine Exakta, earliest ancestorsof the 35 mm SLR camera
Conventionally, the world's first 35 mm SLR camera was
generally said to be the Kine Exakta delivered by the German
company Ihagee in 1936, but later research revealed that thehonor goes to the Sport, a camera announced by GOMZ
(Gosularstvennyi

Optiko-Mekhanicheskii

Zavod(StateOptical-Mechanical Factory)) of the Soviet Union in 1935 andsold in small numbers.

Photograph 5-8

Sport(Provided by JCII Camera Museum)appearance that does not look like any other camera. The
second story of the “two-story structure” has reasons for being,
one of which is the role of the waist-level finder. The typicalwaist-level finder is foldable to improve portability, but theSport cannot be folded because the second story also serves as

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –45

a shelter for the shutter plate (front curtain), which is its second
purpose.
An astute reader may wonder where the other shutter plate(rear curtain) sits waiting, but the answer lies in the “sliding”
incorporated at the bottom of the camera. It is completely
unique. The structure is illustrated in Figure 5-6. After the
mirror rises in the direction of arrow A, the front curtain
retracts in the direction of arrow B and exposure of the film
begins. After the predetermined shutter time elapses, the rearcurtain waiting at the bottom of the camera rises along theguide groove, swinging in the direction of arrow C, to close

Photograph 5-9

the opening, and the exposure ends.

Kine Exakta(Provided by JCII Camera Museum)

The Kine Exakta is a high-quality camera that incorporates

ScreenGermany’s proud tradition of precision metal machining andFront curtain

is comparable to the Leica and the Contax. Its mechanicalFilmappearance overflowing with precision shines to this day. In
addition, features such as the lever mechanism that winds one
frame per pull, the interchangeable finder screen (focusing
screen, hereinafter referred to as the screen) and the sync

MirrorGuide groove

OpeningRear curtain

Figure 5-6 Structure of Sport Shutter

The Sport is an enigma in every respect, but it is a fine SLR

contact installed prior to the Leica reveal a high degree offoresight. The finder is a waist-level fixed type, but a built-in
loupe is available for more accurate focusing. However, themirror is not a quick return type, resulting in a blackout after
shooting, and must be returned back into place by winding.

camera because it reflects the image of the shooting lensThere are many mysterious specifications incorporated in

upward with a mirror, allowing the user to observe the image.

this camera. For example, the lever and shutter release button

However, only a small number were manufactured, andfor film winding are operated by the left hand. In addition, aknowledge of its existence was hard to come by due to thefilm cutter is built into the camera, allowing the shot frames ofclosed nature peculiar to the Soviet Union. Yet, even if thethe film to be removed. The intent behind these mechanisms iscamera had been known, it was too unique in form andnot quite understood, but the concept of this camera seems tofunction to serve as a model for subsequent SLR cameras, andbe one focused on close-up photography and copying. An SLR

in a general sense it is correct to assume that the actual earliest

camera that allows observation of the image of the shooting

ancestor of the 35 mm SLR camera is the Kine Exakta.

lens, as is, is clearly more advantageous for close-up

About the Kine Exakta, Ihagee had already released the best

photography and copying than a rangefinder camera withformat (4 x 6.5 cm) SLR camera, the Exakta, in 1933, andparallax and, when this camera is mounted on a copy stand, thedeveloped the 35 mm format based on the Exakta. The term

waist-level finder is in the ideal position and the winding lever,“Kine” means cine (motion picture) and was so named because

normally operated by the left hand, is positioned on the right-

the camera uses the 35 mm film for motion picture cameras.

hand side. At first glance, it seems inconvenient that the shutter

The best format film has a backing paper like the 120 type film

release button is on the lower side, but this poses no problem

and, in comparison, the 35 mm camera that fed the film byat all since it is natural to use the cable release for copying.

perforations required more precision manufacture, making

With a close-up ring also available as an accessory, so I thinkadvancements in 35 mm SLR camera precision machining

this concept discussed above is most likely quite close to theinevitable.

truth.
(2) The Duflex, boasting incredible innovation
As was the case with the Kine Exakta and the Sport, early
SLRs employed a waist-level finder. The waist-level finder
was widely employed with TLR cameras because of its
extremely simple structure, but has a major drawback with46

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchSLR cameras. That is the difficulty of vertical shooting. Withagainst the idea of making the dimensions, particularly the

the TLR camera, the original Rolleiflex had a square frame, so

overall height, of the camera too large. In order to see the full

there was no need for vertical shooting in the first place, butframe with the Porro mirror type, a large space is required forthis is not the case with the 35 mm SLR camera. With the Sport,

three mirrors, each of a size close to the picture size, instead ofdesigners ducked the issue by separate installation of a reverse

the pentaprism, which inevitably increases the size in the

Galilean eye-level finder. However, it is only natural that theheight direction. If a compromise is made only in the center

user would want to view a realistic finder image formed by thearea, each mirror can be made smaller and an increase in theshooting lens, which is the greatest feature of the SLR camera,

size of the camera can be avoided. The decision was made toat eye level. Such an eye-level finder also facilitates verticalinstall a separate viewfinder for a full-frame view, but theshooting and increases maneuverability. The Duflex was thecompany did not cut corners at all and made it possible tofirst to achieve this eye-level finder for the 35 mm SLR camera.

switch between three types of bright frames.

The Duflex was developed by Gamma in Hungary, and only

The designer of the Duflex, Jeno Dulovits, is a Hungarian.

a small number were manufactured and sold in 1947. Being a

It is very interesting to think that if Hungary remained on themodel born in Hungary during a period of rapid

Western side and the Duflex had been widely known to thecommunization under the occupation of the Soviet Union after

world from the beginning, how its innovation would havethe war, its existence remained unknown in Japan, but in 1969

influenced the later development of the Japanese SLR camera,it happened to catch the eye of a representative of Asahi

especially with regard to the quick return mirror dispute

Optical in Europe, and was obtained and sent to the Pentax

between Asahi Optical and Nippon Kogaku, which will be

Gallery in Japan, where it became known for the first time.

described later. Furthermore, Dulovits could have become a

Details such as its background were introduced in thegreat figure in the camera world alongside Barnack, but when

September 1970 issue of Camera Mainichi.

total production reached about 580, an order to discontinue
production was issued early only because the defect rate was
high4). In the midst of the post-war turmoil, the Soviet Union
invaded Budapest, and Gamma was swallowed by the wave of
the socialist regime.
(3) Contax S, the world's first camera equipped with apentaprism
Currently, the eye-level finder of the SLR camera uses apentaprism (to be exact, a pentagonal roof prism) or apentamirror having a similar optical path. While this principle
has been known since the 19th century and a specific patent

Photograph 5-10

was granted, the pentaprism was not realized because its

Duflexmachining is so advanced.

(Provided by JCII Camera Museum)The features and specifications of the Duflex reveal
incredible foresight. It was an innovative camera equippedwith a number of functions ahead of the Japanese-made SLR
camera that later swept the world, including a Porro mirror
type eye-level finder and a bright frame viewfinder installedside by side, a quick return mirror, an automatic aperture (close
to the idea), a lens mount bayonet structure, a uniaxial nonrotating shutter dial, a metal curtain (a thin curtain that is not a
Contax louver-type) and a focal-plane shutter.
Provision of a viewfinder along with an eye-level finder isstrange at first glance, so a little explanation is needed. The
Duflex eye-level finder allows direct observation of theshooting lens image, but the image is only near the center andthe full frame is not visible. Therefore, a viewfinder is needed
to check the composition. Why the full frame was not madeobservable is unknown, but presumably the designers wereIn 1949, the world's first pentaprism-equipped SLR camera,
the Contax S, was released. Manufacture was achieved by theformer Zeiss Ikon, which had been separated, left on the
Eastern side, and turned into a publicly owned enterprise, andfor the first time the precision pentaprism was mass-produced
by an optical manufacturer that, though separated, still had ahigh level of technical capabilities. Plans for the pentaprism
type SLR camera had been made before the war, and a patentapplication was also submitted in 19415). Naturally, thepentaprism

seems

to

have

been

incorporatedin

Kueppenbender’s concept as well. It has also been pointed outthat the basic design of the Contax S was influenced by the
Duflex. That is, the Duflex System Reflex S equipped with apentaprism was announced in 1948 as a successor to the
Duflex, and the appearances of the unfortunate model that
ended only in this prototype and the Contax S are similar6).
Perhaps there was some form of technology transfer (outflow)

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –47

from Gamma, which dissolved shortly after the announcement.

out with the Western side. The company had no choice but toswitch to the brand Pentacon, and in 1964 the company namewas changed to VEB Pentacon. Furthermore, because there
was also a former KW brand, Praktica, among thoseincorporated into the same publicly owned enterprise after thewar, the SLR brand was ultimately unified to Praktica. New
models of the Praktica SLR camera continued to be released
while making some technological improvements on the
Eastern side until at least 2000. Nevertheless, because thebrand change coincided with the era when Japanese SLRs
swept the market, and because the SLR required a hobby-like

Contax S

quality that satisfies both practicality and the desire for(Provided by JCII Camera Museum)ownership, the brand change cut the camera’s appeal in half

Photograph 5-11

By adopting a pentaprism, the Contax S realized a modern

and its reputation in the market never really took off.

design that would serve as a model for future SLR cameras andhad a great influence on the subsequent development of Japanmade SLR cameras, including the internal layout. An optical
path diagram of the Contax S is illustrated in Figure 5-7.

(4) The Exakta Varex, a finder-interchangeable SLR
In 1950, the Exakta Varex, an improved version of the Kine
Exakta, was released. The special feature of this camera lies in
its waist-level finder that can be replaced with an eye-level
finder employing a pentaprism. That is, the camera is designedwith an interchangeable finder, making it possible to makegood use of the characteristics of the SLR camera, whichreflects the subject image via a mirror to form an image on thescreen, and allow adjustment to the shooting style of the user,whether at eye level or waist level.

Figure 5-7 Optical Path Diagram of the Contax S

The optical path is almost the same as that of a modern SLR
except that the pentaprism is made to “bow” a little, but thisseems to be a sign of efforts to make the triangular roof causedby the pentaprism appear as low as possible. The triangularroof, which is not so strange to our modern eye, was notconsidered pleasing in appearance at that time. However, this“bowing” is surprisingly effective in making the camera looksmaller, and the Minolta αSweet II, which was released about

Photograph 5-12

56 years after the Contax S, was also miniaturized by this same“bowing” method. While it can be said that this “bowing” wasa result of “visiting the old to learn something new,” the use of

The Exakta Varex had only two types of finders, but served

a pentamirror instead of a pentaprism in the Minolta was aas the foundation for the birth of finders with various functions

modern design. By the way, most SLR cameras have thein later Japan-made SLR cameras, such as a finder that

pentaprism upright, but there also exists the Contarex I (seemagnified the finder image (high-magnification finder), a

Photograph 5-14) in which the pentaprism is leaned backwards

finder with a longer eyepoint to improve maneuverability(the mirror's reflection angle exceeds 90 degrees), which is the(action finder, speed finder) and a finder with a built-in

opposite of “bowing.” This may have been to secure space for

exposure meter and automatic exposure function. This model

the exposure meter in front of the pentaprism.

seems to have been quite popular in Europe and the United

The Volkseigener Betrieb (VEB) (Publicly Owned
Enterprise) on the Eastern side, which designed and developed
the Contax S, released models with minor changes, such as theContax D, after this camera, but soon the Contax brand could
no longer be used for export due to a trademark issue that broke48

Exakta Varex(Provided by JCII Camera Museum)States, and appeared in the Hitchcock thriller movie “RearWindow.”
5.2.4

SLR with Lens Shutter

All of the models that have been described thus far as an“SLR camera” have been equipped with a focal-plane shutter.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchFrom the end of the 1950s to the beginning of the 1960s,

could be expected. In addition, use of a lens shutter offers theJapan-made SLR cameras appeared one after the other, and theadvantage that the entire camera can be made smaller because

flow of camera development changed drastically. But, prior to

the internal space for the focal-plane shutter is not required.

this discussion, I would like to break away and touch on the

Furthermore, in flash photography with a flash or the like,form of the SLR camera with a lens shutter. This is because, toeven at the high speeds at which the focal-plane shutter ends

write about Zeiss Ikon on the Western side, such a form cannot

up providing slit-like exposure, the lens shutter always exposesbe avoided.

the entire image, which has the great advantage of enablinghigh-speed synchronization. Perhaps the Contaflex planners
viewed these advantages as more than compensating for the(1) The Contaflex and stumble of Zeiss Ikon
After the war, in contrast to the former Zeiss Group on the
Eastern side which experienced a slowdown, Zeiss Ikon on the

disadvantages, but it turned out that that view was through rosy
sunglasses.

Western side was recovering its business under the commandWith a lens-shutter type SLR camera, it is usually necessaryof Kueppenbender. While introducing spring cameras such as

to keep the shutter open for image observation. To prevent

the Ikonta series, which had been popular since before the war,light leakage with a mirror only is difficult, so a light-shielding

and the IIa and the IIIa, which are improved versions of theplate is required immediately in front of the film. In other

Contax II and III, Zeiss Ikon on the Western side also extended

words, the series of operation sequences at the time of shooting

their tentacles to the development of the 35 mm SLR camera.

becomes extremely complicated, such as press shutter release

In 1953, the long-awaited camera, the Contaflex, made its

button → close shutter, stop down aperture → raise mirror,

debut. The name Contaflex was also given to a prewar TLR

move light-shielding plate away → open shutter → close

camera, but this was a newly developed model that has nothing

shutter → return aperture, return light-shielding plate, lower

to do with the earlier camera.

mirror. If this were a focal-plane shutter camera, the focalplane shutter also serves as a light-shielding plate, making theoperation relatively simple: press shutter release button → stop
down aperture, raise mirror → open shutter → close shutter →return aperture, lower mirror. In fact, the mirror of theContaflex is not a quick return.
In addition, since the lens shutter is naturally located within
the lens optical system, the difficulty in coupling the action of
the mirror and the action of the shutter is problematic, resulting
in poor compatibility with an interchangeable lens function.

Photograph 5-13

With the Contaflex, the designers gave up on theContaflex IIinterchangeable lens and provided, as fixed types, an(Provided by JCII Camera Museum)

The Contaflex is a camera with a Leitz-like beauty inappearance and sense of precision. The SLR, while having alarge and rugged image compared to the rangefinder camera,
has a width of 127 mm, which is nearly 10 mm smaller thanthat of the Leica IIIf. Equipped with a pentaprism, the camera
is tall, but features a Fresnel lens mounted on its finder which
gives a brilliant aerial image, making image viewing extremely
easy. The back cover is removable and integrated with thebottom side of the traditional Contax, and the winding knob,
film counter and shutter release button are coaxial, echoing thesimplicity of the Contax II.
However, the lens of this camera is not interchangeable. The
reason is that the company despised the complicated anddelicate focal-plane shutter and installed a lens shutter instead.
Lens shutters are widely used in spring cameras and TLR
cameras and, because there were specialized manufacturers
such as Deckel and Gauthier, when delivered as a unit, savingsin the labor required for development were achieved and, atthe same time, reductions in development and product costs

attachment type conversion lens capable of obtaining atelephoto effect of 1.7 magnification and several close-up
auxiliary lenses called Proxars for close-up photography.
However, the greatest feature of an SLR camera –the ability todirectly observe the image of any shooting lens as long as thelens is attachable – was narrowed by these lenses being fixed.
Some of the lenses of later models were interchangeable towide-angle, telephoto and close-up lenses by interchanging thefront lens group, but Zeiss's high-quality large-diameterinterchangeable lens group could not be used.
The Contaflex made frequent model changes, and as a result,continued to sell for almost 20 years until the early 1970s.
However, at least in terms of sales, and apart from in the earlydays, the camera ranked far below Japan-made SLR cameras.
Then, compared to Japanese models equipped with a quick
return mirror as a matter of course, the Contaflex with its“pitch black view after shooting” until the final model in 1970
was technically completely behind the times.
Furthermore, as a result of allocating development

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –49

capabilities to the Contaflex, it was no longer possible torelease a successor to the Contax IIa and IIIa, which also
dropped out of the competition with the Leica.
Zeiss Ikon positioned the Contaflex as an intermediate
model and may have been intended to leverage the Contarex I,
which was equipped with a focal-plane shutter and released in
1960, in the high-end model field, but the Contarex I was very
expensive, big and heavy, and with its strange styling shownin Photograph 5-14, there was no way to beat Japan's full-scale
SLRs, including the Pentax AP, the Minolta SR-2, the Nikon
F and the Canonflex, that appeared one after the other in thelatter half of the 1950s, and thus Zeiss Ikon withdrew from thecamera market in 1971 and became a lens specialist.

Photograph 5-14

Contarex I(Provided by JCII Camera Museum)Why did Zeiss Ikon employ a lens shutter in the Contaflex?
As mentioned above, it may be because of miniaturization andcost advantages, but presumably Zeiss had a close relationshipwith Deckel, a long-established, highly skilled lens shutter
manufacturer. Deckel's flagship product, the Compur shutter,
was praised for its high quality since that time, adopted byvarious models including the Zeiss, and highly regarded. Most
likely use of a shutter produced by Deckel, with which Zeiss
Ikon was so familiar, seemed attractive when advancing into
the SLR, and as a result, was given a higher priority. Anotherthing, in the development of the SLR, perhaps Zeiss Ikon
found it difficult to install a Contax-type vertically traveling
shutter due to the camera layout. Because the SLR has anobservation screen just above the shooting frame, with verticaltravel, there is no place to install the windup shaft with aContax-type shutter. With a modern (non-windup) verticallytraveling metal focal-plane shutter, installation is possible, butsuch a design had not been developed yet in this era. This madeit necessary to develop a new horizontally traveling, that is, aLeica-type, focal-plane shutter, but perhaps the hurdle seemed
too high.

type SLRs, could be bought at a relatively reasonable price,and therefore certainly was a hit such as it was. Witnessing this,many manufacturers entered this field. In Germany, Kodak's
Retina Reflex and the well-established Voigtlander
Bessamatic are famous.
While this document describes a model equipped with a
focal-plane shutter as representative of the mainstream, there
is also the fact that lens-shutter-type SLRs, such as theContaflex mentioned above, prospered for a while and so, eventhough the topic deviates from the main subject of thisdocument, I will describe the unique technology of thedomestically produced 35 mm lens shutter type SLR forreference.
This type, which can reduce manufacturing costs including
development costs by using ready-made lens shutters, was also
incredibly attractive to domestic manufacturers, and aconsiderable number of products were released from the 1960s
to the 1970s mainly in the field of popular cameras. Although
Tokyo Optical and Kowa aggressively commercialized suchcameras, it is remarkably interesting that Nippon Kogaku andCanon, whose main products were focal-plane shutters, also
temporarily introduced lens shutter type SLRs in the popularmodel price range.
Here, the technology will be explained using, as an example,
the Topcon Wink Mirror S of Tokyo Optical, which pursued
functionality, as a representative work of a domestic lens
shutter type SLR.
Tokyo Optical was established along with Katsuma Kōgaku
Kikai in 1932 as a manufacturer of optical weapons mainly for
the Army, with the surveying instrument factory of Seikosha
serving as the base. With its background similar to that of
Nippon Kogaku, which had a close relationship with the Navy,
the two companies were called “Toko of the Land, Nikko of
the Sea” with the name Toko certainly standing for Tokyo
Optical in Japanese (Tokyo Kogaku) and Nikko certainly
standing for Nippon Kogaku. While Nippon Kogaku would
advance to camera manufacture after the war, Tokyo Opticalentered the camera business in 1936 before the war, producing
lens shutter cameras such as the Lord and the Minion, andsupplying lenses such as the Topcon and the Simlar to othermanufacturers. After the war, Tokyo Optical released TLRs
and the like, followed by the focal-plane shutter type SLR, theTopcon R, in 1957, and the lens shutter type SLR, the Topcon
PR, in 1959. The Topcon strategy was to equip high-end 35
mm SLRs with focal-plane shutters and popular models withlens shutters. The Topcon PR was not equipped with a quick
return mirror yet, and the lens was fixed, but 1963 ushered in
the release of the Wink Mirror S equipped with a quick return
mirror and an interchangeable lens with a dedicated bayonet
mount.

(2) Domestically produced lens shutter type SLRs
That Zeiss camera, the Contaflex, described in the previous
section, though not of “good pedigree” due to the installationof the new light-shielding plate and the complexity of the
shutter operation sequence, which are peculiar to lens shutter

50

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchand the light-shielding plate on the camera side.
Subsequently, the Topcon Wink Mirror S developed into
the Topcon Uni and the Unirex and, while the field of the lens
shutter type SLR established a certain position in the popular
SLR genre until the 1970s with the Kowa models and the like,
subsequently the advantages were gradually reduced with thepractical application and development of the unitized metal
focal-plane shutter, and the lens shutter type SLR faded away.
Photograph 5-15

Topcon Wink Mirror S

5.3 The Infancy of Domestic Cameras and(Provided by JCII Camera Museum)The epoch-making feature of this model is that, instead ofbeing an interchangeable type only in terms of the lens front
group like the Contaflex, the entire lens was interchangeable
like a focal-plane shutter type SLR. To achieve this, theSeikosha SLV300 G shutter, specifically designed by Seikoshafor SLR cameras, was used. Figure 5-8 shows the principles
behind the camera mechanisms and the coupling of the shutter.
Aperture
Shooting lensto domestic camera manufacturers, but to what extent
depended greatly on the position of each company at that time,
as described in Section 5.2.2. Among the manufacturers ofLeica-type focal-plane shutter cameras, those lacking thewherewithal and resources to shift to SLR development wentbankrupt or were absorbed by other companies in the early
1960s. On the other hand, before the appearance of the M3,

Shutter blade
MirrorOvercoming their Technical Issues
The “M3 shock” of 1954 brought about a big turning point

Asahi Optical, which released the Asahiflex, the firstLight-shielding plate

domestically produced 35 mm SLR in 1952, and othermanufacturers were well aware of the merits of the SLR overFilm
Shutter unit
Light-shielding plate returns
by shutter closed signal

the rangefinder camera, so most likely hardly felt the M3 shock.

Shutter opens and closes
by light-shielding plate
retraction signal

What is interesting is that while most of the “cottage makers”
among the group of manufacturers of lens shutter cameras,such as TLRs, that are not focal-plane shutter cameras ran outof steam, all manufacturers within this group that had a certain

Figure 5-8 Operation of the Topcon Wink Mirror S

amount of capital participated in the SLR camera battle. These is the state before shooting. The mirror is lowered andthe light-shielding plate is closed, but the aperture and the
shutter are open, allowing observation of the subject image
with the finder. Now, when the shutter release button ispressed, the mirror rises in the direction of the arrow. The
mirror, the aperture of the unit shutter and the shutter blade arecoupled, and so as the mirror rises, the aperture stops down toa predetermined value, the shutter blade closes, and the state
shifts to .
 Once the mirror has completed retracting, the lightshielding plate starts to rise in the direction of the arrow. At
this point, the shutter blade is closed, so there is no exposure.
 A signal is output when the light-shielding plate iscompletely retracted, causing the shutter blade to open andclose, and the film to be subject to a predetermined exposure.
 The lock that held the mirror and the light-shielding plateis released by the closing action of the shutter blade, and eachcomponent starts its return. The light-shielding plate returns
first, and light leakage is prevented by the opening action of
the shutter coupled with the mirror. The aperture is also
coupled to the mirror and so, when the mirror returns, theshutter opens, the aperture opens, and the state returns to .
In this way, it was possible to realize a quick return mirror
almost in the same way as a focal-plane shutter type SLR while
intricately coupling the shutter on the lens side and the mirror

manufacturers should not have been very affected by the M3
shock. So, from a different point of view, perhaps the M3 justhappened to be announced when the 35 mm SLR, which began
in Europe from around 1936, had been gradually blooming
over a period of just less than 20 years before and after the war.
At the very least, the trend of the times demanding a varietyof photographic expressions undoubtedly boosted thebreakthrough of the SLR suitable for use with super-telephotolenses and close-up lenses. The appearance of the M3 was justthe beginning, and it seems that the flow from the rangefinder
camera to the SLR was extremely natural in the field ofcameras equipped with focal-plane shutters. Whatever thereason, there is no doubt that the interests of Japanese camera
manufacturers gradually or instantly shifted to the SLR since
the Photokina in 1954, though some differences exist for eachmanufacturer.
In the early 1960s, Japanese camera manufacturers
suddenly turned to the SLR, but as for Germany, which was aleader in the camera industry, Leitz focused on the rangefinder
camera, Zeiss on the Western side strayed from the royal roadwith the lens shutter mounting, Ihagee, manufacturer of theKine Exakta, took time to overcome the shortcomings of the
SLR, and Zeiss on the Eastern side failed to show any
remarkable development after the Contax S due to the isolation

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –51

and rigidity peculiar to the socialist system.
During this period, Japan turned the tables on Germany interms of both sales and quantity in the camera industry, and to
this date Japan’s position remains unchanged. The situation is
illustrated in Figure 5-9.
Camera Production Trends in Japanand West Germany

No. produced (1,000 units)West Germany
Japan

Year

Figure 5-9 Change in Number of Cameras Produced inJapan and Germany7)

company gradually got on track as an optical lensmanufacturer as before the war, aiming to enter the camera
market.
Matsumoto had the foresight and ambition to bet on the
future of the SLR while other manufacturers were looking at
easy-to-enter market genres such as the TLR. Asahi Optical is
the only domestic manufacturer that released an SLR before
the appearance of the Leica M3. Matsumoto's extraordinary
sense and ability to execute can be seen here as well.
The Kine Exakta had already been on the market as a 35
mm SLR camera for more than 15 years, and although it was
far behind, Asahi Optical's first camera and Japan's first 35 mm
SLR camera, the Asahiflex I (“I” was later added for
distinction), emerged in May 1952. According to one theory,the plan was to combine the 6 x 6 format SLR, which was
popular at the time, with the Leica compact precision camera,
and this is worth considering. Alternatively, around 1950, bothCanon and Nippon Kogaku had already released highly
complete rangefinder cameras, and perhaps Asahi Opticalthought that it was not a good idea to counter them head-on.

In this section, I will describe in detail the process oftransition to the SLR by each camera manufacturer, thetechnology that overcame various issues and became thecornerstone of development, and the models that were epochmaking.

5.3.1

Entry of Domestic Camera Manufacturers into
35 mm SLR Market (until 1950s)
The following explains the background of the entry of each
Japanese camera manufacturer into the development of a 35mm focal-plane shutter type SLR, and the technical featuresand product concept of each representative model, in this order,
while including anecdotes and the like. Since there were many
manufacturers, separate descriptions will be given for theperiod through the 1950s and then the period from the 1960s.

(1) Asahi Optical, producer of first domestically
produced 35 mm SLR
Japanese cameras, which were developed one after the otherafter the war behind the Leica, were influenced by Barnack
Leica to a greater or lesser extent and competed for victory in
the field of rangefinder cameras similar to the Leica. Only
Asahi Optical was different. Asahi Optical started its businessin 1919, and gained its ability as an optical manufacturer
through lens production as a subcontractor of Konishiroku andChiyoda Kogaku Seiko. In 1936, when times were becoming
more military-charged, the founder, Kajiwara Kumao, became
suddenly ill and his nephew, Matsumoto Saburō, who was stillin his early twenties, became the successor, and the company
was inevitably incorporated into the munitions industry andsuffered from the destruction of factories due to air raids.
Nevertheless, despite such difficulties, business resumed after
the war, starting with the production of binoculars, and the52

Photograph 5-16

Asahiflex I(Provided by JCII Camera Museum)The finder of the Asahiflex I was a waist-level type, but thecamera was also equipped with a reverse Galileo-type
perspective finder for vertical shooting. Adding a perspective
finder to the waist-level finder, which is completely unsuitablefor vertical shooting, is a method readily evident in early SLR
cameras overseas. Since the pentaprism-type Contax S was
already released in 1948, the adoption of a pentaprism shouldhave been considered, but probably because it was the firstcamera by Asahi Optical, it seems the company did not wantto overdo it.
In addition, the camera was equipped with agroundbreaking semi-quick return mechanism. It is designed
so that when you press the shutter release button, the mirror
retracts, and when you release your finger from the shutter
release button after shooting, the mirror returns. Releasing thefinger after shooting is substantially a natural movement, andthus well addresses the drawbacks of SLR and the blackout
problem, though not completely. Two years later, the IIB
equipped with a quick return mechanism that quickly returns
the mirror in conjunction with the travel of the rear curtain of
the shutter after shooting came to fruition, which will be
described later.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchOf course, Matsumoto planned this camera, but Suzuki
Ryōhei and Yoshida Nobuyuki were actually in charge of thedesign. These two were transferred from Konishiroku, which
resulted in Asahi Optical making the lens of Konishiroku's
popular camera, the Pearlette8).
The Asahiflex I, the earliest ancestor of the domestic 35 mm
SLR, was improved to the IA, IIB and IIA over the next few
years, and steadily developed into the Asahi Pentax, the first
SLR equipped with a pentaprism (later called Pentax AP for
distinction) in 1957. Asahi Pentax, as the name implies, wasequipped with a pentaprism. In addition, the 37 mm dedicatedscrew mount was changed to a larger diameter M42 screw, that
is, a so-called Praktica screw mount (hereinafter referred to as
M42 mount). This screw mount was adopted by the Praktica
released in East Germany in 1949, and was widely used due toits easy-to-manufacture, standardized 1 mm pitch metric finethreads.

(2) The Miranda T, the first domestically produced
camera equipped with a pentaprism
As for the pentaprism method, which is the most suitablefinder optical system for SLRs, the Prismflex Mamiya wasannounced in 1952 by Mamiya Optical as a prototype. In
addition, Orion Seiki Sangyō (later Orion Camera and thenMiranda Camera) also announced the prototype of the Phoenix
in 1954, and at the beginning of 1955, the existence of a
prototype equipped with a pentaprism called the Altair was
known.
The year after the announcement, the Phoenix became thefirst pentaprism-equipped SLR camera released in Japan under
the name of the Miranda T. The Miranda T was epoch-making
in that the finder was interchangeable, but included many oldfashioned parts such as an old shutter dial that rotates while the
shutter is operating, a biaxial high-speed/low-speed format,
and a mirror that was not a quick return type.

While subsequent cameras such as the Miranda were finderinterchangeable types, the aim was to separate from thepentaprism type and reduce the size and weight of the body,and the clear concept and reasonable price were widely
accepted, making the model popular. From here, the Pentax
brand began to make a leap forward as a representative ofdomestic SLRs.
Photograph 5-17

Miranda T(Provided by JCII Camera Museum)

Subsequently, the company continued improvements andreleased various SLRs, with a particular emphasis on exports,
including models bearing the Soligor brand for overseas. The
Miranda held a certain position in the SLR market, but had lessindividuality than other SLRs. In addition, the following was
also pointed out, indicating poor quality:
Ogura Iwao, who was a doctor at Asahi Camera magazine's
famous corner, “Camera Diagnostic Room,” tells the story that,when he worked for a US company in the early 1960s, six
Miranda SLRs were brought into the company, but one month
later all broke down due to the exact same phenomenon9). At
the time, the Japan Camera Inspection Institute had beenchecking export cameras, but had difficulty completing
durability tests, so the defect must have been missed.
Miranda Camera was acquired by an overseas company in1969, and unfortunately the company ended production of
SLRs in 1976, but the brand name Miranda remains in history
as the first domestically produced SLR camera equipped witha pentaprism.
Among the other prototypes that sought to be equipped witha pentaprism, the Prismflex Mamiya was never mass produced
since Mamiya Optical was busy producing the flagship 6 x 6format camera. Nevertheless, from my point of view, it seems
that the difficulty of machining the pentaprism is the main
reason why the pentaprism-equipped cameras of each

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –53

company other than Phoenix ended as prototypes. As acapital in order to purchase an automatic lathe made inpractical matter, the angle of the surfaces (the roof-shaped
portion), which is a characteristic of the pentaprism, is required

France11).
This sincere attitude toward “the making of things” stands

to be exactly 90 degrees and a rounded ridgeline, if existent,
affected visibility, requiring machining to a sharp edge.

out starting with the Zunow, described later, and presumably
has been the driving force for its long-held leadership role in

However, at the technical level of the time, the yield must havebeen extremely poor due to problems such as inadequate

domestic SLRs.

machining accuracy and ridgeline chipping.
(4) The Topcon R with a complete lens lineup(3) Asahiflex IIB equipped with quick return mirror

About two years after the Miranda T, Tokyo Opticalreleased the Topcon R in November 1957, making it the third

Asahi Optical released the Asahiflex I improved version,
the IIB, in 1953. This camera is the first model in Japan to use

manufacturer of domestically produced 35 mm focal-plane
shutter SLRs. While the Asahiflex and the Miranda T

a quick return mechanism for the mirror. Some oldcommentary books indicate it was “the world's first,” but asprototype, the Phoenix, launched development before theLeica M3, the Topcon R was the earliest released after the M3.

mentioned above, that spot was ceded to the Duflex of
Hungary, which would become known to Japan in later years.

This shows the high level of development and technicalcapabilities of Tokyo Optical. Though much heavier than the

However, without knowledge of this predecessor, the camera
was highly praised for its originality in conception. The

Asahiflex and the Miranda T, the camera was steadily put
together by the designer, Zenyōji Kenichi. As mentioned

designer of this epoch-making mechanism is YoshidaNobuyuki mentioned above. Yoshida was that type ofabove, Tokyo Optical had also been working on thedevelopment of a lens shutter type SLR from early on. For theindividual who made mockups of things before sketchingdrawings and would have his subordinates make the drawings

company origin and its lens shutter type SLR camera, refer to
Section 5.2.4.

of his handmade products10). It is an anecdote reminiscent ofBarnack.
As mentioned above, the Asahiflex I had already adopted asemi-quick return mechanism. That is, with the Asahiflex I, thenecessity to return the mirror immediately after shooting wasunderstood, but a perfect quick return could not yet beachieved, and the company would only realize the ideal for the
first time with the Asahiflex IIB.
Photograph 5-19

Topcon R(Provided by JCII Camera Museum)

The Topcon R was greatly influenced by the Exakta line.
First, the Topcon R emphasizes a systematic design, has aninterchangeable finder, and adopts a highly versatile Exakta
lens mount. Then, the semi-automatic aperture uses an external
coupling mechanism that imitates that of the Exakta.
With its release, eight interchangeable lenses, from a 35 mm
Photograph 5-18

Asahiflex IIB(Provided by JCII Camera Museum)

It is speculated that the reason why Asahi Optical, at firstjust a mere subcontractor, became one of the leading SLR
manufacturers was not just its clear concept of the camera
itself, but also its culture of valuing production technology.
Asahi Optical exhibited cautiousness from its onset with therepair and maintenance of machine tools damaged by air raids
followed by preparation of jigs and tools and then thetransition to mass production, and courage in its decision to,upon seeing that SLR production would expand, scrape
together an amount of money equivalent to three times its

54

wide-angle to a 300 mm telephoto, were simultaneously
announced. The 35 mm F2.8 lens probably represents Japan's
first retrofocus optical system of domestic manufacture. The
300 mm was a so-called “Sannippa (328)” with a large
diameter of F2.8. These also are a testament to the high levelof optical design technology achieved by Tokyo Optical.
A semi-automatic aperture mechanism was adopted forthree of these interchangeable lenses. First, the aperture ischarged to open via a release lever provided on the lens barrel,
and an aperture button that works coaxially with the shutter
release button on the camera side is provided on the tip of thearm on the lens. Pressing this aperture button when shooting
an image stops down the aperture, and pressing it further

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchpresses the shutter release button on the camera side, causing
the mirror to rise and the shutter to operate.
With this method, the aperture is in a stopped-down state
after shooting, making it necessary to manually recharge toopen the aperture. Even though the mirror used a quick return
method, the fact that the subject image remained dark after
shooting remained as a point needing improvement. In
addition, in order to realize this externally coupled semiautomatic aperture, the shutter release button on the camera
side was arranged on the front side instead of the upper side. It
looks strange at first glance, but this is not bad for operability.
The shutter was the first focal-plane type for Tokyo Optical,
and the shutter dial, being a high-speed/low-speed two-stage
type and not non-rotating, was a little outdated, but these weresteadily improved with a fully automatic aperture adopted in
the RII (common name; released in July 1960) and a nonrotating uniaxial type adopted in the RIII (released in

Photograph 5-20

Minolta SR-2

(Provided by JCII Camera Museum)The design, however, is something to behold. The flowing
elegance created by Shiramatsu Shō became a major feature ofsubsequent Minolta SLRs13). Shiramatsu is a designer who had
contributed ideas about cameras to the monthly magazine
Shashin Kōgyō since he was a student, and Chiyoda Kogaku

September 1961).

Seiko noticed his extraordinariness and recruited him.
Consideration was given to systematic design and, while the(5) Chiyoda Kogaku Seiko’s Transition to SLR cameras

finder was fixed, an angle finder (which can be attached to theeyepiece and viewed from above) and a magnifier (which

The Minolta brand Chiyoda Kogaku Seiko was also greatly
influenced by the appearance of the Leica M3. The company

magnifies the viewfinder image) were available. Sixinterchangeable lenses were also available, from a 35 mm

had already established a certain position as a 35 mm focalplane shutter camera in the Minolta 35 series, but after seeing

wide-angle to a 600 mm super-telephoto.
Despite the major policy change, the technical capabilities

the M3, planned a full model change of the existing
rangefinder camera. From the President, Tajima Kazuo, down,of Chiyoda Kogaku Seiko, which entered the 35 mm SLR
camera in just one and a half years, are remarkable. The

all worked together to prepare for the M3 pursuit, kicked off
the endeavor at the end of 1955, reviewed everything including

company incorporated the camera brand into the company
name in 1962 and became Minolta Camera.

the shutter, rangefinder and design, and made the decision to
design and develop a model named the Minolta Sky.

(6) The Zunow, a phantom SLR

The prototype was completed in 1957 and was shown to a
distributor in the United States, home to the largest market. But,

When you unravel the history of domestic SLRs, you willdefinitely come across the Zunow. The camera was called thesurprisingly, the rangefinder camera received a lukewarm
response and, conversely, development of an SLR was

Zunow Pentaflex when announced in the April 1958 issue ofthe monthly magazine Shashin Kōgyō, and thus Zunow

strongly proposed.
Normally, there would be hesitation here, but Tajima's

Pentaflex is its official name. But, since this camera is the oneand-only Zunow SLR, the Zunow or the Zunow Camera

decision was quick and, as soon as he returned to Japan, heshelved the Minolta Sky and made a major shift tosuffices. Looking at the features and specifications
incorporated, the camera is so advanced that it is hard todevelopment of the SLR12). It is the corporate culture of
Minolta to take such an opportunity to boldly change its course,

believe that it was released in 1958. The camera is equippedwith a quick return mirror, a fully automatic apertureand the company continued to subsequently do the same time
and time again.

mechanism and a pentaprism, and thus completely overcame
the shortcomings of the SLR. Moreover, because the finder

The company's first SLR camera, the Minolta SR-2, wasreleased in October 1958. It is an orthodox camera lacking

and the screen were interchangeable, and the equidistant,uniaxial non-rotating shutter dials were used, they were far

distinctive features. The camera suppressed key points such asa quick return mirror, a uniaxial non-rotating shutter dial andahead of other companies’ cameras at that time in terms offunctionality.

a self-timer, and was a semi-automatic type in which theaperture was returned by the next film winding.

Furthermore, the design entrusted to the GK Industrial
Design Incorporated was truly advanced as it was based on
straight lines. “The embodiment of the Noh spirit” wasreportedly the design concept. The overall height of the camera
is even shorter than that of the Pentax AP, which is a typicalcompact SLR of this period, and it is a daring camera design
even now. The GK Industrial Design Incorporated was

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –55

founded by Ekuan Kenji, a well-known industrial designer, isfamous for the design of Kikkoman tabletop soy sauce bottles,
and later participated in the design of the World Expo 1970 in
Osaka.

properly followed with the Zunow. Reportedly, hundreds ofunits were painstakingly released to the world, but there was a
problem with quality and they were returned one after another.
The fact that the finder was an interchangeable type but nofinders were released other than the camera-equipped standard
model hints at insufficient preparation.
Zunow Opt. went to the trouble to set up a company called
Shinkō Seiki to produce this camera. In today's terms, thestrategy was “fabless” production, but it seems there wereconsiderable problems with the level of production technology
and design studies.
There were also functional problems that likely stemmed
from mistakes in the initial concept design, and the long-

Photograph 5-21

Zunow

(Provided by JCII Camera Museum)The greatness of the Zunow does not end there. Zunow Opt.,
which made the Zunow, made F1.1 night photography lenses
at the request of the Navy during the war, when it called itself
Teikoku Kōgaku Kenkyūjo. Taking advantage of thatexperience, the company also prepared a 58 mm F1.2 large
diameter lens for the Zunow.
The lens mount adopted the spigot type. In contrast to thebayonet or screw mount in which the lens is mounted by being
rotated, in this type the lens itself is fixed with a tightening ringat the base without being rotated. The positions of the camera
and lens in the rotational direction could therefore be
determined accurately, making use of a fully automatic
aperture advantageous. The FD mount that Canon later
adopted in the professional F-1 model and the best-seller AE1 was also of this type, and the focal point was good.
The designer was Arao Kiyoshi, who had transferred from
Chiyoda Kogaku Seiko Co., Ltd. Arao's skill in designing suchfunctions ahead of the industry leaders Nippon Kogaku andCanon is immeasurable. Nevertheless, as fate would have it,
Arao left the company due to conflicts with the company
around the release of this camera, and the camera itself wasextremely short-lived.
From the spring of 1958, the company placed a large
number of advertisements in camera magazines, but the reality
was that the camera was still in the trial stage where troubles
frequently occurred. Subsequently, problems did not go away
and the company held a presentation for the general public at
Nihombashi Mitsukoshi department store in August. Although
it seems that the release of the camera was a snap decision by
the company, there are no records indicating whether this was
so or not. This might simply be because just a few prototypelevel models were sold to important customers only.
In general, for cameras with new functions (although not
limited to cameras), the various functions are checked in trial
production, then a mass production trial is performed to
identify problems in mass production, and transition to themass production process cannot be made until all problems
have been solved, but there is no evidence that this process was

56

awaited fully automatic aperture was slow in operation,
resulting in incidents of the aperture lagging behind in time tothe shutter travel. This was probably due to a poor balance
between the moment of inertia and the stopping down force.
The height of ambition as an SLR was comparable to thatof the Nikon F released the following year, but while the Nikon
F became a long-selling camera for about 15 years, Zunow,both the company Zunow and the camera Zunow, disappeared
into the darkness with a slight glow like a meteor. While theZunow models that still exist today are few in number with
virtually none working perfectly, categorizing the camera as aphantom camera today, the Zunow will forever be legendary
as a rare camera that solved (or attempted to solve) almost allof the problems related to the SLR at once.
After leaving the company, Arao joined Mamiya Opticaland was in charge of designing TLRs and 6 x 7 size SLRs.
(7) Differentiation by Canon of rangefinder and SLR
camerasAt this time, Canon, which had already established itself asa major camera manufacturer, chose a slightly different way
when entering the SLR market. The company decided tocontinue pitching the rangefinder camera. Perhaps it wasaiming for profits by being the rangefinder camera’s soleremaining manufacturer, with other Japanese manufacturers
moving away from it.
First, Canon put their efforts into developing the VT and the
VL. For film winding, the L was a lever type and the T had atrigger lever at the bottom, improving richness in variation. In
addition, the cameras countered the M3 finder with a variablemagnification finder. Furthermore, in 1959, Canon released
the P. P is an abbreviation for Populaire (French for “common
people”), and the strategy was to price the camera in the
popular price range and differentiate it from the expensive M3.
With the advent of the P, Leica-type rangefinder camera
manufacturers who could not enter the SLR camera market
were completely finished.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchPhotograph 5-22

Canon P

(Provided by Canon Camera Museum)

Canon's rangefinder cameras subsequently remained alive
and well, securing a certain position as a low-priced version of
the Leica and maintaining its standing as a domestic
rangefinder camera with models such as the 7 and the 7S. Whatis unforgettable about the 7 and the 7S is the Canon 50 mm
F0.95 ultra-large diameter lens. There was a time when Nippon
Kogaku released the Nikkor 50 mm F1.1 for rangefinder
cameras and Zunow also released the Leica 50 mm F1.1,
competing for the title with a large-diameter lens, but Canon
was one step ahead at least in terms of brightness.

Photograph 5-23

Canon 7S

(Provided by Canon Camera Museum)In the end, the only company in Japan that did not simply
abandon the rangefinder line even with the debut of the M3
and demonstrated the tenacity to continue selling therangefinder camera until nearly 1970 was Canon.
On the other hand, Canon also, of course, anticipated thefuture of the SLR, and released the Canonflex in May 1959,
one month ahead of Nippon Kogaku. It seems that thecompany's underlying strength was to achieve entry into the
SLR market while continuing to develop the rangefinder
camera.

Photograph 5-24

Canonflex(Provided by Canon Camera Museum)

The Canonflex is the first domestically produced SLR thatcan be coupled with an exposure meter. When a dedicatedexposure meter is attached to the right shoulder of the camera,
the meter is coupled with the shutter dial and the appropriate
aperture value can be derived and displayed from the subject
brightness and shutter speed. However, this dedicatedexposure meter was sold separately. The viewfinder isinterchangeable, the mirror is a quick return type, and a portionof the dedicated lenses have automatic aperture capabilities.
A wide variety of interchangeable lenses were prepared, butwere biased toward the telephoto side, suggesting that thecompany intended to segregate the telephoto system to the
SLR and the wide-angle system to the rangefinder.
The Canonflex has a well-crafted exterior, a beautiful
design with the pentaprism cover painted black, and a lens
mount that uses a spigot R mount of the same type as the
Zunow. The R mount is compatible with the later FD mountexcept for the aperture coupling system and has a large
diameter, and thus the future was well thought out. However,this camera was extremely short-lived. Production was
discontinued about three months after its release. The reasons
are not clear, but it may be because the size was larger than the
Nikon F released soon after, and the bottom trigger lever type
winding was not suitable for general use.
Subsequently, from the 35 mm SLR to the digital SLR today,
Canon and Nikon have been ranked the top two manufacturers
in the SLR category by the press. While the Nikon F became abig hit selling about 860,000 units, Canonflex finished withjust under 20,000 units in just three months. The fact that there
was such a big difference in the debut of the first SLR debutsby the top two is unbelievable today.

(8) The Petri, entering the SLR market via the lowpriced route
So far, description has been made of the entries into thedomestic 35 mm focal-plane SLR market for eachmanufacturer in chronological order. In summary, the order is
1952: Asahi Optical, 1955: Miranda Camera, 1957: Tokyo
Optical, 1958: Chiyoda Kogaku Seiko, Zunow Opt., 1959:
Canon, and then 1959: Nippon Kogaku, Kuribayashi Camera,
1960: Yashica, Konishiroku Photo Industry, but the first SLR
from Nippon Kogaku, the Nikon F, is a prominent figure in thehistory of the 35 mm SLR in Japan and will be revisited in alater section.
Kuribayashi Seisakusho (later Kuribayashi Camera, Petri
Camera and now Petri Kōgyō) was founded in 1907 and is thesecond oldest domestic camera company in the industry after
Konishiroku. Before the war, the company made lens shutter
cameras, such as spring cameras and TLRs, under the brand
named First, but in October 1959 it entered the SLR market
with the first Petri brand SLR, the Petri Penta. Petri's SLR
strategy was characterized by its low-priced route. The priceof the first product, 28,000 yen for the Petri Penta, comparedto the SLR camera released in the same year, is less than half

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –57

the 69,500 yen for the Nikon F and even 20% cheaper than the
Asahi Pentax S2, which was strategically set at a popular priceof 35,000 yen by Asahi Optical (both are prices with an F2lens).

manufacturers in terms of automation of exposure, it was latein competing in SLR miniaturization in the early 1970s, and,moreover, a significant labor dispute broke out, resulting in the
resignation of the entire management team. Subsequently, theunion continued to develop and produce cameras
independently, but withdrew from camera production in 1976.
To the general public, more than the camera, the Petri namebecame identified with labor disputes that became suchhopeless messes that they were taken up in the Diet.
5.3.2

Nippon Kogaku: From Entry into the Camera
Market to the Nikon S2 and SP
Going back a little, though there may be some overlap, let's

Photograph 5-25 Petri Penta(Provided by JCII Camera Museum)This low-price strategy was somewhat effective and secured
the company a certain position in the SLR genre. The camera
also had technical strengths, employing original mechanisms
such as a film counter coupled to shutter operation (usuallycoupled to film winding), and a structure with a long camshaft
installed at the bottom for controlling the mirror, shutter andthe like by its charge and rotational operation.
To further explain this camshaft system, which is Petri's
original mechanism, as shown in Photograph 5-26, thecamshaft installed on the bottom of the camera is charged by
the winding operation and starts rotating via the release
operation. A cam for driving the mirror, a cam for shutter
release, and the like are arranged in various places, and each
operation is initiated at an appropriate timing. With thecamshaft centrally controlling each part, stable operation canbe achieved.

take a look at the flow from postwar camera market entry to
the SLR at Nippon Kogaku. My boss, Satō Akihiko,interviewed several alumni who were in the design department
in earlier years about early camera development at Nippon
Kogaku, which was to be left as records, and I had theopportunity to inspect these documents. Based on that
information, I will describe the flow while adding my thoughts.
After the war, Nippon Kogaku, which was cut off from theproduction of optical weapons, decided to shoot for consumer
camera development. The leader was Fuketa Masahiko, amechanical designer who joined the company in 1937 and,during the war, designed mechanical computers called fire
control systems that used about 35,000 gears to calculate thetrajectory of anti-aircraft guns and torpedoes.
After the war, Fuketa was in charge of designing consumer
cameras, initially prioritized the development of the TLR andcompleted trial production, and even decided on the productname “Nikoflex;” but problems with the reliability of theoutsourced shutter could not be solved. Since it would cost an
enormous amount of money to introduce jigs, tools andmachinery to develop a lens shutter in-house, the company
abandoned the TLR and decided to develop a 35 mm focalplane camera. According to Fuketa, if it was the focal-plane
shutter, he was confident in in-house development. Perhaps,
Fuketa thought that, compared to the lens shutter, which
requires development costs and development time for press

Photograph 5-26 Petri Camshaft System (Camera: V6II)

Appearance-wise, the camera features a shutter releasebutton installed diagonally on the front side. Exemplary of thisdesign is the Contax S, but according to the designer
Yanagisawa Akira, the arrangement is to make space for the
layout of the upper surface.
While Petri has had an image of being cheap or bad, in myhigh school days, around 1970, there were quite a few students
using the Petri V6 or V6II. In short, Petri cameras were theonly SLRs affordable in terms of price, yet there was not muchmention of quality problems such as breakdowns.
The company, which was renamed Petri Camera in 1962,
continued to take the low-priced route in its release of SLRs,
and although the company managed to keep up with other58

dies and the like, development of the focal-plane shutter,
which had many lathe-turned parts, could reduce such costs
and time, and thus would be easier to develop.
Shortly after the war, in October 1945, instructions to startdevelopment were given, and disassembly and analysis of the
Leica and the Contax began, but there is an anecdote that
Fuketa made an employee angry upon discovery that Fuketa
had disassembled the camera he had lent to him. The drawings
were completed in half a year, and the prototype a year later,
but there were many problems such as poor material quality,
which led to a change from the machining of aluminum die
casting –which had a lot of cavities – to sand casting, film
scratches due to foreign matter on the film pressure plate andthe useless piano wire, not Swedish-made, for springs14). Even

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchso, the I, the M and the S sold well to the US military,
launching the camera business of Nippon Kogaku.
(1) Leica M3 countermeasures by Nippon Kogaku
At the time of the announcement of the M3 in 1954, Nippon
Kogaku was just about to release the Nikon S2, which was afull model change of the S. The company quickly postponed
the announcement for about half a year to counter the M3, andtook measures to urgently carry out improvements to thewinding lever, finder magnification and the like. As time wasrunning out, some of the countermeasures were insufficient,but had some effect, and the S2 boasted the largest quantity
sold among the Nikon rangefinder cameras.

Photograph 5-27 Nikon S2(Provided by JCII Camera Museum)At the same time, in order to approach the epoch-making
finder of the M3, Nippon Kogaku started development of theSP, a high-end rangefinder camera with a novel finder opticalsystem that supports as many as six types of interchangeable
lenses. This camera was released in September 1957, became
the flagship model of the Nikon brand, and is still often
referred to as a famous model, but due to the high retail price,
the sales volume did not reach that of the S2.

Subsequently, Nippon Kogaku released the S3, a low-priced
version of the SP, and the S4, a popular model, but the feelingsof the development team had already shifted to SLR
development.
(2) Birth of the Nikon F
Fuketa was aware of the future of the SLR from an earlystage, and started SLR development with a slight delay by
diverting the mechanisms of the SP. Based on the stories of
Fuketa and Matsunaga Gorō, who was in charge of the design,
the full-scale start of development was around the fall of 1956.
The reason why the camera was developed in the format ofdiverting the high-end rangefinder camera and the shutter
mechanism of the SLR was to omit the time required to design
each of the two while keeping in mind the division of roles,
with the former being strong in the wide-angle realm and thelatter being strong in the telephoto realm. The sales teamfirmly requested a rangefinder camera, that is, a camera that
could counter the M3, and the development of the SLR, which
did not interest them so much, was carried out in a freeatmosphere led by the design and development team. This
anecdote illustrates the contrast in philosophies between thesales side, which seeks immediate action, and the development
side, which has a more long-term perspective.
The F, the first Nikon brand SLR camera, was released inJune 1959. The SLRs of Asahi Optical, Tokyo Optical,
Minolta, Canon and other companies were already on themarket, and although the F was just about the last SLR toemerge from among the major companies, it was extremelycomplete. Above all, the systematic nature, which is thegreatest feature of SLRs, was well thought out. By the end of
the year of release, the lens lineup ranged from a 21 mm ultrawide-angle lens to a 500 mm ultra-telephoto lens. The
viewfinder and the screen were also interchangeable, making
it possible to support various shooting genres according toapplication. Subsequently, when the built-in camera exposure
meter became mainstream, the company took action byreplacing it with the Photomic finder. Furthermore, the factthat a motor drive could be installed to allow continuous
shooting was epoch-making, which greatly expanded themarket share in the press.

Photograph 5-28 Nikon SP(Provided by JCII Camera Museum)

Photograph 5-29 Nikon F(Provided by JCII Camera Museum)The camera specifications and functions were also
extremely innovative. The camera was equipped with a fully
automatic aperture that stopped down to the set aperture value
only during shooting and instantly returned to the open
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –59

aperture after shooting, as well as a quick return mirror that
retracted during shooting and instantly returned. The Nikon F
was quite early to realize these two functions, except for the
Zunow, which had virtually disappeared overnight. Various
mechanisms will be described later, including the quick return
mirror mechanism, which became a hot topic in the fierce
patent dispute with Asahi Optical after its release.
In addition, a mirror lock-up mechanism was also provided
to support fisheye lenses and ultra-wide-angle lenses. With
these lenses, when a retrofocus optical system is not adopted
in pursuit of miniaturization, the lens back end comes close to
the film surface side, requiring a mirror lock-up mechanism
for getting the mirror out of the way in advance. Even more,
the camera had a preview button that made it possible to checkthe depth of field in advance, the viewfinder frame coverage
was the ideal 100% and the bright screen was also wellreceived.
The adopted lens mount was a large-diameter bayonet
mount for that time, and this F mount was the standard for
Nikon SLRs for nearly 60 years and still is so today. For
example, the Nikon Df, a digital SLR released in 2013, can beequipped with a lens released at the same time as the Nikon F,
that is, a lens that is more than half a century old, even if its
functions are limited, and used to take pictures.
The Nikon F is a masterpiece in the history of the SLR and
was well received by the press, professional photographers,
and advanced amateurs for a long time until discontinuation in
1974.
(3) Mirror and aperture drive mechanism of the Nikon F
In the development of the Nikon F, Fuketa instructed
Matsunaga to set two priorities: to have a viewfinder frame
coverage of 100% and, to the extent possible, to utilize thevarious mechanisms of the Nikon SP for the winding systemand shutter system. Considering that an entire mirror box
would have to be added to adopt the mechanisms of therangefinder camera in an SLR, the task certainly proved moredifficult than was expected. Therefore, from a modern
perspective, there was something slightly but undeniably
redundant about the Nikon F’s combination of a shutter releasemechanism and mirror/aperture drive mechanism.
Nevertheless, due to the clever design of Matsunaga et al., thecamera turned out to be a model boasting excellent durability
and reliability. Here, the mirror and the aperture drive
mechanism will be described with reference to Figure 5-10.
<<Shutter release to mirror-up>>(1) When the shutter release button (not shown) ispressed, the mirror release hook 2 is pressed in the
direction of arrow A, mirror 1 is unlocked, and themirror-up action of mirror 1 is triggered.

Figure 5-10

Mirror Mechanism of the Nikon F(2) This rotational torque is obtained by the mirror drive
spring 9 rotating the link 7 in the B direction with its
left arm and rotating the mirror drive lever 10 in the
direction of the arrow C via the link 8.
(3) Since the mirror drive lever 10 and the fork-like mirror
drive arm 12 rotate integrally, the mirror 1 rotates inthe direction of arrow D and rises.
<<Mirror-up to shutter travel>>(4) When the mirror-up action is completed, the shutter
front curtain travels by a mechanism (not shown) to
start exposure, and then the shutter rear curtain
travels.
(5) The travel motion of the rear curtain of the shutter istransmitted as shown by the arrow F, and the holding
lever 5 rotates counterclockwise to disengage from themirror vertical lever 3.
(6) The mirror vertical lever 3 is pulled to the left in the
figure via the connecting rod 6 by the force of theright arm of the mirror drive spring 9, and the convex
part near the center of the mirror vertical lever 3
pushes the link 8 and rotates the mirror drive arm
integrated with the mirror drive lever 10 in the
direction opposite to the arrow C in a movement
reverse to the mirror-up action to lower the mirror.
<<Charge of drive mechanism>>(7) When the winding lever is wound after a series ofshooting operations, the charge lever 4 pushes theupper end of the mirror vertical lever 3 to the right,
and the mirror vertical lever 3 is hooked onto theholding lever 5 and held to complete charging.
The remarkable point of this mechanism is that both themirror-up and the mirror-down are performed by a single
mirror drive spring 9. This is possible because the torque fromthe right arm of the mirror drive spring 9 is higher than thetorque from the left arm by an amount equivalent to thatthrough the mirror vertical lever.
Normally, when a quick return mirror is designed, it iscommon to prepare two springs, a spring for mirror-up and aspring for mirror-down, and the Asahiflex and the Duflex havesuch a design. The Nikon F was also similarly designed in the
beginning, but there is a reason why the design was changed

60

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchto the above mechanism midway through development; there
was a conflict with Asahi Optical's utility model right.
Asahi Optical submitted a patent application for the quick
return mirror mechanism of the Asahiflex IIB, but since Tokyo
Optical had already submitted an application for the principle,
rights were granted only after downgrading the application toa utility model. On the other hand, in the design of the Nikon
F, Nippon Kogaku was most likely not too concerned about
the utility model right of Asahi Optical since Tokyo Optical
was first to file. However, a lawsuit was filed by Asahi Optical,
and while the dispute was ostensibly continued, Fuketa
hurriedly changed the design in case the company lost,
resulting in the mechanism described above. In the end,
camera critic Kitano Kunio and the Ministry of International
Trade and Industry at that time set out to settle the muddied
dispute. In an era when the camera was a prize product in theexport industry, such an internal conflict was not desired. The
conditions of the settlement were not announced, but it is said
that Asahi Optical approved the use of the utility model rightand Nippon Kogaku paid some unrelated amount15).
Even so, despite the sudden design change, Fuketa’s talent
as a mechanical engineer who created a quick return mirror
mechanism that is so simple and avoided contention isamazing. I was shown this mechanism shortly after joining thecompany, and for a while I could not understand how themirror-up and mirror-down worked. I then moved thecomponents around, and finally understood. It is quite
impressive. I will never forget when I was taking the company
employment test and had an interview with Fuketa who was
the Vice President at the time.
(4) Anecdotes in the development of the Nikon F
The Design Division Manager, Fuketa, assigned Matsunaga
Gorō to the development of the F. Matsunaga joined thecompany during the war and was in charge of the fire control
systems for torpedoes. It seems to be a quirk of fate that, like
Fuketa, Matsunaga moved from being in change of fire control
systems to the consumer camera, completely different areas.
After the war, Matsunaga demonstrated his abilities not onlyin the mechanical design of the Nikon S, but also in various
fields such as various testing machines and lens barrels. At thattime, Nikon lenses included the Nikon S mount and the L
mount for the Leica, and by being widely responsible for these,
Matsunaga was able to clearly solidify the concept of the
Nikon F mount when designing the SLR. The design strategy
reportedly was to design the F mount first, attach the mirror
box to it, and then build up the other mechanisms.
Anecdotes about Matsunaga indirectly reached my ears as
well. His nickname within the company was “The Edison of
Nikon,” and it said that he also liked it. Matsunaga left thecompany less than two years after the launch of the Nikon F
and moved to a high-speed camera manufacturer, later
revealing that he made the transition because he wanted towork on measurement-related equipment and devices.
Certainly, looking at the Nikon F, the camera has durability

and reliability, allowing use not only as a consumer camera butin academic fields as well. Based on the results of a durability
tester designed by Matsunaga himself, these qualities wereachieved by involving the in-house metal material laboratoryand devising materials and heat treatments of worn parts.
Although the Nikon F is often hailed as a famous camera
nowadays, its reputation at the time of its release was not sogreat. What reveals this is the evaluation in the New Face
Diagnostic Room in the June 1959 issue of Asahi Camera.
Although there are problems in representation, more than halfof the article is negative. To give an example, the front side ofthat characteristic pentaprism of the Nikon F is ridiculed as“the triangular headband worn by ghosts,” a reference to theappearance of ghosts in Japanese folklore. The design of the
Nikon F was the work of an outside designer, Kamekura
Yūsaku. To the extent that Kamekura was given a dedicatedroom inside Nippon Kogaku to design the camera, muchenergy was put into the endeavor, but to be humiliated in thisway was unbearable for the Nippon Kogaku design team.
Hori Kunihiko, a designer, and a public relations officer
went to the Asahi Camera editorial department to protest, but
nothing came of it. This event became a hot topic in theindustry because Shirai Tatsuo, who was in the editorial
department at that time, compared the event to the February 26
Incident and called it a “raid by young officers,” but when I
joined the company and asked Hori, who was a production
technology related director, to act as an intermediary for somework, I found that he was a very gentle person who kindly
taught me various things, and I understood that thecharacterization “raid” was a bit of hyperbole.
The fact that one of the best magazines in the industry
dismissed the hot new model makes one think, though theexpression is old, of the good old days when there were nosuch shackles. Despite the headwinds created by the article,
the Nikon F eventually became popular and became theleading SLR in Japan. This article is legendary even now, morethan half a century after its appearance, partly because of theinteresting comparison.
Kamekura Yūsaku was in charge of not only the exterior
design of the F, but also the artistic design of promotional
posters, packaging, catalogs, instruction manuals and the like,and the originality in his work became a hot topic.
Subsequently, Kamekura was active in designing emblems andposters for the 1964 Tokyo Olympics, and became one ofJapan's leading graphic designers.
5.3.3

Entry of Domestic Camera Manufacturers into
35 mm SLR Market (From 1960s)
With the dawn of the 1960s, the domestic SLR market saw
dramatic development. It was a time when camera overall sales
surpassed those of West Germany in terms of both amount andquantity.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –61

In 1960, the first Japan Camera Show was held. The show
was sponsored by the Japan Camera Industry Association(currently the Camera & Imaging Products Association), andwhile the name changed to Photo Festa Japan, Photo Expo andPhoto Imaging Expo with subsequent changes in thecomposition of the co-sponsoring organization, the show is
now established as CP+ and is held every spring at Pacifico
Yokohama. During the Japan Camera Show era, the show washeld in major cities all over the country, and served as a great
opportunity for PR with camera fans living in rural areas.
The 35 mm SLRs of each brand, such as Pentax, Canon,
Nikon, Minolta and Topcon, which already entered the SLR
market, released a number of successors and variations andenhanced the interchangeable lens group. Then, there was anincrease in the number of cases of entry into the SLR market
by manufacturers that produced cameras of other genres.
Precisely at this time, the camera market and the SLR market
were booming like never before, as Japan as a whole was
enjoying a favorable business climate with the 1964 Tokyo
Olympics just around the corner. The entry of major
manufacturers into the SLR market through the 1950s was
described in the previous section, and those who subsequently
entered are summarized below.
(1) SLR market entry by the long-established
Konishiroku
Konishiroku is one of the longest-established shops in Japanin the photography industry, based on the Konishiya
Rokubeiten, which began selling photographic materials in
1873. In 1903, the company launched the first domestically
produced Cherry Hand Camera for amateurs, and since thentook domestic leadership in all fields related to photography,
contributing to the market expansion of cameras mainly in the
popular price range. By the way, Japan's oldest photographyrelated trading company, Asanuma & Co., Ltd., was foundedin 1871, about two years earlier.
The company enjoyed its spring camera Pearl series as abest seller before the war, developed and produced military
aerial cameras and the like during the war, and released smalllens shutter cameras and TLRs under the Konica brand after
the war, but never touched the Leica-type 35 mm focal-plane
shutter camera. This is because they focused more on popularcameras than on high-end cameras.
Of course, the company was aware of the movement of thetimes toward the SLR, and around 1955 to 1957 madeprototypes of an orthodox horizontal-travel cloth curtain focalplane shutter and a vertical-travel split-type metal blade focalplane shutter. The former is known as a prototype with the
KONIFLEX-35 engraving, and the latter is known as theKonica Flex. The latter was finally selected as a camera formass-production, and was released overseas as the Konica F in
March 1960, about a year after its announcement in 1959.
While the shutter of the Konica F was not yet unitized, by thetime it was released, the Copal Square unitized by joint

62

development with the shutter manufacturer Copal was massproduced and installed in the low-priced Konica FS releasedin Japan in the same year as the Konica F. Since then, thenumber of SLRs equipped with a vertical-travel split metal
blade focal-plane shutter, which became the standard for
subsequent SLRs, gradually increased, and their origin can beseen in the Konica F.

Photograph 5-30 Konica F(Provided by JCII Camera Museum)

The Konica F was equipped with this highly advanced
shutter and achieved a high shutter speed of 1/2000, as well asa flash synchronization speed of 1/125 that took advantage ofshutter travel in the short-side direction of the frame.
Furthermore, the camera was equipped with uniquemechanisms such as a built-in external exposure meter coupledwith the aperture, an interchangeable viewfinder, a swing-back
type quick return mirror and a pressure plate retreat
mechanism that prevents frictional resistance and film
scratches when winding the film. Surprisingly, however, thecamera was short-lived. The release was delayed for more thana year from the Nikon F and, being expensive, big and heavy,
and lacking consideration in terms of operability with a lessthan-ideal shutter release button position and poor holding feel,proved no match for its competition.
However, by fusing the SLR development technology
cultivated with this camera and the unique technology of
Konishiroku, the Konica brand SLR has gained a certain
position mainly in the genres of intermediate and popularmodels since then.
(2) Yashica entry into SLR market with Nicca
technology
I have already written about how Yashica introduced focalplane shutter technology by absorbing and merging Nicca
Camera, manufacturer of Leica copies, and Zunow Opt.,
manufacturer of SLRs. The result was the release of the
Yashica Pentamatic in the spring of 1960. This camera featuresa large-diameter lens mount, which gives it a luxurious feel.
Furthermore, the camera also introduced unique technologies
such as a combined accessory shoe and rewind knob, but thesemi-automatic aperture and lack of features such as a selftimer, preview mechanism, automatic number counter
restoration and mirror-up function left a slightly half-finished

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchimpression, and sales-wise it could not be called a success.

mount, was released, but only two years later the Prismat CP

Yashica changed its strategy from a high-end model with its
own mount to the popular J series, which had changed to awith a M42 mount was released, resulting in inconsistency inthe lens mount to say the very least. While perhaps thisversatile M42 mount. Although the Yashica Penta J-3 had abuilt-in external CdS exposure meter, it was set at a lower priceoccurred because the company introduced the optimum
technology at the time of each release, it also caused confusion

than the cameras of other companies to secure a certain market
position.

on the user side. This trend continued until the 1980s with thelens mount changing six times in about 20 years. Although thelast ZE mount was the first to be equipped with a full-fledged
electrical contact to show off its advancedness, in the end the
product did not become mainstream in the 35 mm SLR world.
With Mamiya Optical often called “Karakuri no Mamiya”[Mamiya, the company of mechanical gadgetry] and having
continuously come up with one original idea after the other, it
is a pity that the company could not come up with a clear
strategy for the 35 mm SLR.

Photograph 5-31 Yashica Penta J-3(Provided by JCII Camera Museum)

Subsequently, through collaboration with Tomioka OpticalCo., Ltd. (later Kyocera Optec Corporation), a longestablished optical manufacturer, Yashica aimed to improve
SLR technology and continued to make medium-sized SLRs
mainly in the popular camera price range. This would later
blossom as the Contax brand.
(3) Mamiya Optical, a company willing to change themount
Mamiya Optical, which had strong ability as a mediumformat camera manufacturer, also entered the 35 mm SLR
market with the Mamiya Prismat CLP in January 1960.
However, this was an export-only model, and its first domestic
release was the 1961 Mamiya Prismat NP.

(4) Olympus, taking the world by storm with its halfsize
Olympus Optical Co., Ltd. (currently Olympus), founded in
1919 as a microscope manufacturer under the name Takachiho
Seisakusho, made a foray into cameras with the SemiOlympus I in 1936, and worked on a wide range of spring
cameras, TLRs, and 35 mm lens shutter cameras. Maitani
Yoshihisa, who later became known as Oskar Barnack inJapan, joined the company, and the camera that he planned
himself as part of training was the Olympus Pen. The picture
size of 17 x 24 mm, which is half that of the Leica, and the
double number of shots were well received by the family
demographic at that time, and the subsequent Pen series lineup
was a big hit.
The Pen F was planned as the half-size flagship SLR, also
known as the “Pen size,” and was released in 1963, making it
the first Olympus 35 mm focal-plane shutter SLR. Being halfsize, the Pen F cannot be compared to a Leica-format camera,
but was a really unique camera.

Photograph 5-32 Mamiya Prismat NP16)

Mamiya Optical had already prototyped the Prismflex
Mamiya equipped with a pentaprism in 1952, and had
subsequently announced a number of 35 mm SLR prototypes,
but because the main medium-format camera was doing well,

Photograph 5-33 Olympus Pen F(Provided by JCII Camera Museum)

As you can see from the outside, this camera does not havelowered its priority, considerably delaying its release to themarket from the first trial production.

the triangular roof or pentaprism that a normal SLR shouldThis model employed a highly versatile Exakta mount, but
used a unique external coupling semi-automatic apertureof the Porro mirror system used in some early SLRs, such asmechanism for the aperture. In 1962, the Prismat WP, which
realized a fully automatic aperture with a dedicated bayonet

have. Instead, it uses a finder optical system that replaces a partthe Duflex, for example, with a prism. The optical system is
illustrated in Figure 5-11.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –63

The coupling for shutter charging is performed via a gear
located near the bottom of the camera, and thus couples
naturally when the unitized shutter is attached to the chassis of
the camera body. It is a skillful design considering assembly
workability.
Most of the shutter curtain is made of titanium having athickness of 0.03 mm, other than the ribs having a thickness of
0.04 mm in a radial pattern. According to Maitani's book, he
had a hard time with this shutter curtain, optimizing it throughFigure 5-11

Optical System of Olympus Pen F

Utilizing the vertically long frame 3, the image from thephotographing optical system 1 is reflected once laterally by
the movable mirror 2 and guided to the eyepiece by the prism
8 via the prism 5, the mirror 6, and the lens 7. With this opticalsystem, the top surface of the camera is as sleek as arangefinder camera. In exchange, the left side is longer whenviewed from the front, but this makes it convenient to holdwith the right hand, so the configuration kills two birds with
one stone.
The vertically long half-size resulted in another original
mechanism. That is the rotary focal-plane shutter shown in
Photograph 5-34.
The rotary shutter has the advantage of requiring only one
fan-shaped curtain and, in accordance with the operation of the
shutter curtain, is circular as a whole. Unlike a normal focalplane shutter, the structure is relatively simple because themomentary exposure is performed by rotating the curtain.
When viewed from the front of the camera, the mechanism thatdrives and controls the shutter curtain is located at the bottom
left, avoiding interference with the triangular first prism thatguides the captured image, and is shaped to secure space.

a process of repeated trial and error on matters such as
thickness and the machining of uneven surfaces, andpurposefully eschewed any increase in mass to the extent that
he did not even paint it. Therefore, when the back cover isopened, a dull silver shutter curtain can be seen, but the camera
is free of problems such as light leakage. Thanks to his hard
work, it became possible to increase the curtain speed, and thecamera achieves 1/500 second high-speed synchronization
with flash use, which was thought to be difficult for focalplane shutters. Among the SLRs at that time, the Konica F was
capable of a high shutter speed of 1/2000 seconds, but
considering that the synchronization time was only 1/125,
Maitani’s camera had amazing specifications.
The Pen F achieved a high degree of miniaturization due toits original and rational layout. There is no wasted space inside
and the appearance is slick. Such features exude not only
Maitani's imaginative power and technical sense, but also his
aesthetic sense, and that spirit would be passed on to later
products, the M-1 and the XA.
Olympus entered the 35 mm SLR market with a very uniqueand bold model, earning itself a solid reputation, and, like othercompanies, kept pursuing the challenge posed by the Leicaformat SLR. This was because, with the price of film
decreasing and the value of a half-size “capable of taking twice
as many shots” diminishing, the odds were against the camera,
with its hard-to-overcome disadvantages of a vertically long
frame when held and its inferior enlarged photos due to such asmall frame.
The first Olympus SLR in the Leica format was the
Olympus FTL, the first release of which was in the UnitedStates, in 1971. It was a so-called “makeshift” model that thedevelopment team reluctantly made at the insistent request ofa major US dealer. This was because, although developmentof the full-scale system SLR M-1 had started, it would take

Photograph 5-34 Shutter of The Olympus Pen F

64

another three years to bring the products to the market, and so
a separate development team was assigned to the task. This
uncoordinated operation made the FTL an extremely shortlived camera.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchPhotograph 5-35 Olympus FTL17)

Photograph 5-36

The M-1 (renamed OM-1 immediately after its release) was
released in 1972. Certainly, the camera, taking only three years
to develop and featuring ingenuity in not only the productconcept of miniaturization, but also its various specifications
and functions, is an epoch-making model that makes a namein the history of the 35 mm SLR. Details of the camera will be
described in the next chapter in the discussion onminiaturization.
(5) Ricoh
When considering the entry of various manufacturers into
the 35 mm focal-plane shutter SLR market, Riken Optical(currently Ricoh) was an unfortunate manufacturer greatly
affected by World War II. Before the war, Riken Opticalproduced cameras that used 127 type film, such as the Gokoku
and the Ricohl I and IIB, from early on with focal-plane
shutters, but after serving as a wartime munitions factoryduring the war, technology succession going into the postwar
period did not go well.
Even so, the company gained strength with the legendary
blockbuster, the Ricohflex III, in 1950, considered ways toenter the SLR market while taking a side glance at the SLR
breakthrough, and finally around 1960 received a supply of
Copal unit shutters. In this way, the Ricoh Singlex TLS
released in July 1962 made its debut in the SLR market. Thismodel does not have any major features, but the successor
Ricohflex TLS401 released in 1970 adopted, instead of apentaprism, a pentamirror system that achieves the same
optical system by combining multiple mirrors. Since thepentamirror is standard in modern SLRs in the popular pricerange, the company certainly exhibited extreme foresight.
Moreover, with its advantageous hollow structure, the camera
adopted an epoch-making mechanism that allows the user toswitch between eye-level and waist-level views with a dial.
This technology will be described later.

Ricohflex TLS401(Provided by JCII Camera Museum)(6) Other domestic SLR manufacturers
Other Japanese manufacturers that entered the SLR market
include the Fujica, Cosina and Chinon brands, but the years ofentry were after 1969, which was considerably behind theaforementioned manufacturers, and the cameras offered few
functions that surpassed those of previous models.
Nevertheless, as the companies gained experience, latermodels had some distinctive specifications. For example, theFujica ST701 introduced an LED display in the viewfinder,
and the ST901 made it possible to digitally display the shutter
speed. These unique models and their specifications will betouched upon in the next chapter to the extent possible as partof the progress and development of various functions.
References and citations
1)

Satō, Takatoshi. Raika no Shikumi [How the Leica Works],(Green Arrow, 2000), p.32.
2) Satō, Takatoshi. Raika no Shikumi [How the Leica Works],
p.28.
3) Japan Camera Industry Association, Nippon Kamera
Kōgyōshi [The History of the Camera in Japan], (Japan
Camera Industry Association, 1987), p.376. (Graphics byauthor)4) Kurashikku Kamera Senka No. 61 [All about Historical
Cameras No. 61], Kine Ekizakuta kara Hajimaru
Kurashikku 35mm Ichigan-refu [35mm SLR, from the Kine
Exakta onwards], (Asahi Sonorama, 2001), p.91.
5) Sakai, Shūichi. Raika to Sono Jidai [The Leica and its Era],(Asahi Shimbun Publications, 2000), p.285.
6) Kurashikku Kamera Senka No. 9 [All about Historical
Cameras No. 9], 35mm Ichigan-refu Kamera [35mm SLR
Cameras], (Asahi Sonorama, 1987), p.8.
7) Nippon Kamera Kōgyōshi [The History of the Camera inJapan], p.384. (Graphics by author)8) Ogura, Iwao. Kokusan Kamera Kaihatsu Monogatari [TheStory of Camera Development in Japan], (Asahi Shimbun
Publications, 2001), pp.134-138.
9) Ogura, Iwao. Kamera to Sensō [The Camera and War], (TheAsahi Shimbun, 1994), pp.92-93.
10) Ogura, Iwao. Kokusan Kamera Kaihatsu Monogatari [TheStory of Camera Development in Japan], p.150.
11) Ogura, Iwao. Kamera to Sensō [The Camera and War],
pp.146-148.
12) Kamio, Kenzō. Raika ni Oitsuke! [Catch up with the
Leica!], (Asahi Sonorama, 1995), pp.136-141.
13) Kamio, Kenzō. Mezasu wa Raika! [The Aim is the Leica!],(Soshisha Publishing Co., Ltd., 2015), p.260.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –6514) Asahi Camera. Nyūfēsu Shindanshitsu Nikon no Ougon
Jidai 1 [New Face Diagnostic Room – Nikon's GoldenAge], (The Asahi Shimbun, 2000), pp.205-206.
15) Arakawa, Tatsuhiko. Fukkoku Akarui Anbako [(Reprint) The
Bright Dark Box], p.174.

Cameras No. 9], 35mm Ichigan-refu Kamera [35mm SLR
Cameras], p.91.
17) Kurashikku Kamera Senka No. 9 [All about Historical
Cameras No. 9], 35mm Ichigan-refu Kamera [35mm SLR
Cameras], p.102.

16) Kurashikku Kamera Senka No. 9 [All about Historical

Thinking about picture size
There are various picture sizes for silver halide cameras, but this paper focuses on cameras that use 35 mm film and have a picture sizeof 24 x 36 mm.
Picture sizes are standardized by the international standard ISO 1754, and there are various sizes including medium-format in addition
to 24 x 36 format. The Japanese Industrial Standard JIS B7115, which corresponds to this ISO standard, specifies a wider variety of sizes,
including the 10 x 16 size that was once used in the Minolta 16 as well as other devices that use 16 mm film.
Looking at these standards, the upper and lower tolerances of 24 mm in length and 36 mm in width are +0.8/0. It seems that the large
tolerance in width is due to the fact that, depending on the type of lens, the diffraction of light affects the picture size. The standards areconditional in that they "apply to frames taken with a standard lens," but it is difficult to define a "standard lens" in the first place.
Nowadays, lenses with a focal length of around 50 mm are often called standard lenses, but this is based on the fact that the Leica
Anastigmat, which was the lens when the Leica was released, happened to be a 5 cm F3.5.
Subsequently, attempts were made to define a standard lens, but none of them were persuasive, and now there is only a philosophicaldefinition that "the standard lens is the one having the focal length that the user or manufacturer considers to be the standard,” isn't there?
There is a reason why the tolerance is on the positive side. That is, although securing 24 x 36 mm is preferred, there are circumstanceswhere a larger picture size is problematic. In the case of the SLR, there are models that claim 100% viewfinder frame coverage, but since
the finder's field frame is fixed, the field of view decreases relatively as the picture size increases. Therefore, the idea of "securing 24 x 36mm, but making any increase as close to 0 as possible" is expressed in the one-sided tolerance +0.8/0.
In that respect, the panoramic size born in the United States has a width of 36.4 mm ± 0.4 mm, which is the same as the actual 24x36
size, but is expressed by the median and distribution tolerance. This is probably because the first product of this size was a "one-time-use
camera" whose performance was not mentioned.
Although I am straying off the subject, there is a tendency to set the drawing dimensions to the median + distribution tolerance due tothe influence of 3D-CAD in mechanical design. While such dimensions are easy to understand, the design concept might be ignored, so I
believe the one-sided tolerance method should be prioritized.
By the way, the Leica was not the first camera of this most popular 24 x 36 format size, but this size became popular due to the
popularity of the Leica, and so even today is understood as the "Leica format.” Nevertheless, most likely because they do not want to use
the brand names from other countries or other companies, manufacturers in Japan often call this format the 35 mm format or full-size
instead of the Leica format. Aside from the 35 mm format, "full-size" seems a little strange. Some digital cameras these days are less than
24 mm long and/or less than 36 mm wide, and yet use the term "full-size.” The reason I think specifications should adhere to “+0.8/0”
vertically and horizontally when “full-size” is declared is perhaps because I am partial to silver halide. However, it may be argued thatfull-size is not the size including the tolerance, but rather the nominal value of 24 x 36.
Whether standard lens or full-size, I feel once again that the definition of words ought to be clarified from time to time to prevent
problems from occurring later.
Note that this paper uses the term “the Leica format” in honor of Barnack, rather than the “24 x 36 format” name specified by ISO.
Besides, “the Leica format” is simple as a term whereas “the 24 x 36 format” is redundant.

66

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March6 Development of SLR Camera and Evolution of Technology
Up to the previous chapter, I have described how major
Japanese camera manufacturers entered the SLR camera
market. Since the beginning of the 1960s, the 35 mm SLR
market, spurred by these manufacturers, has grown
dramatically and Japan has dominated the market ever since.
In this chapter, we will look at the history of thisbreakthrough from the aspect of the technological evolution

Rear curtain shaft (winding side)

Rear curtain shaft (feeding side)

Four-shaft type

Shutter curtain

Film cartridge

Spool
Film

Sprocket

Shutter front/rear shaft

and development of each function.

6.1 Development of Focal-Plane Shutter

Front curtain shaft (feeding side)

Front curtain shaft(winding side)

Three-shaft typeThe small focal-plane shutter for 35 mm film, born from theinspiration of Oskar Barnack, became the foundation ofsubsequent shutters. While this shutter had almost the ultimate
configuration from the beginning, fundamentals aside, minor
improvements such as increases in speed, productivity
improvements, miniaturization, unitization and overcoming
other shortcomings were progressively made.
In the 1960s, from the Leica-style horizontal-travel winding,a new type of shutter that allows multiple metal blades to travelin the vertical direction of the frame emerged based on aconcept unique to Japan. To this day, this type of shutter has
become the mainstream, including in digital SLR cameras.
This section describes the development process for thesevarious types of focal-plane shutters.
6.1.1
Form of Horizontal-Travel Focal-Plane Shutter
The horizontal-travel focal-plane shutter is based on the
Barnack design, with the feeding side of the shutter curtains
being a thick, drum-shaped shaft. In order to distinguish thistype from the thin two-shaft type subsequently developed, I
will call this type the three-shaft type, combining the single
shaft with the two shafts on the winding-side of the curtains.
In contrast, the type subsequently adopted in many
domestically produced SLR cameras is a four-shaft type inwhich the feeding side of the curtains is separated with two
shafts in the front and rear, respectively.
A transverse cross-sectional view of each shutter isillustrated in Figure 6-1. In the three-shaft type, the shaft on
the side that feeds out the shutter curtains is a thick shaft and,as mentioned in the Leica section, rotates independently for thefront curtain and the rear curtain in the thrust direction(direction perpendicular to the paper surface).
In the three-shaft type configuration, the thick shaft onlyrotates a little less than one turn and is thus compatible withthe brake system, the winding system and the like, and the rearcurtain in the standby state is thickly wound, resulting in theadvantage of being less susceptible to stress and curlingcompared to the four-shaft type. However, due to the “thickshaft,” the three-shaft type occupies space inside the camera,
causing the width of the camera in particular to become large.

Figure 6-1 Shutter Transverse Cross-Sectional View

The design conceived to narrow the horizontal width of thecamera was the four-shaft arrangement. Minolta paid attention
to this arrangement from early on, and already adopted thedesign in the company's first 35 mm focal-plane shutter camera,
the Minolta 35I, which was released in 1947. Subsequently,
this design was adopted by many SLR cameras, including
Canon, because of its space efficiency. In terms of flagshipmodels from the early days of the SLR camera, Nikon andTopcon used the three-shaft type, while Pentax, Canon and
Minolta used the four-shaft type. Canon adopted three shafts
in its rangefinder cameras and four shafts in its SLR cameras,
taking advantage of their respective characteristics.
In the 1970s, the withdrawal of Topcon from the camera
market and the acceleration of miniaturization led to anincrease in the proportion of four-shaft cameras, and leading
SLR camera manufacturers, such as Olympus and Yashica,
also adopted the four-shaft type. The Nikon F3, which wassold for more than 20 years starting from 1980, wassubstantially the final runner as a three-shaft type following
the Leica tradition. The shutter of the F3 is shown in
Photograph 6-1.

Photograph 6-1

Unit Shutter of the Nikon F3This focal-plane shutter incorporated the trends of the time,such as unitization and electronic control, but the basic
configuration itself, such as the thick shaft structure on thefeeding side of the curtains, does not deviate from that of theinitial Leica.
This shutter curtain is made of thin titanium. Although early
History of Cement Manufacturing Technology

67

focal-plane shutters that started with the Leica used rubberized
cloth curtains, there was a movement to make the curtains outof metal as a measure to protect against temperature change
and pinholes caused by condensing sunlight. Nippon Kogaku
focused on titanium from the start and adopted metal curtains
in the Nikon F, with the exception of the very early models. It
turns out that titanium is an excellent material as a curtain fora horizontally traveling shutter, and was actively used forabout 40 years until production of the Nikon F3 wasdiscontinued. As Nikon's proprietary technology, the titanium
curtain is embossed, which has the effect of preventing
scratches and, when wound, preventing adhesion andstabilizing shutter travel due to the thin air layer created by theembossing.

shutter base plate, and form a parallel link with the respective
blades of the front and rear groups.

Rear blade
group

Front blade
group

Aperture(Opening)

Figure 6-2 Blade Configuration of the Copal Square

Photograph 6-2 Embossing of Titanium Shutter Curtain

As for other metal materials, stainless steel curtains wereused in Canon's early SLR cameras. These curtains, however,
did not become mainstream due to stainless steel having a highinertia compared to titanium, and Canon eventually adopted
the titanium curtain as well.
6.1.2
Debut of Split Metal Blade Type Shutter
The idea of using a thin metal plate for the shutter existedfrom the early stages. For example, the Sport, the originator of
the 35 mm SLR camera mentioned above, reflects this idea.
Unlike an SLR camera, a rangefinder camera does not have amirror, and thus the shutter curtains may be exposed to a bright
light source such as sunlight, and pinholes due to the heat arelikely to occur. Therefore, metal became the focus and, as
explained with the Contax I, a method of processing metal
plates into a louver shape and then having the shutters travel
vertically during winding was adopted.
Around 1960, a completely new type of focal-plane shutter
emerged. This new shutter was a split-type metal blade shutter
adopted in the Konica F (each blade is formed of elastic thinmetal plates). With both the front and rear blades being formedof a plurality of thin metal plates, the distinctive feature ofthese blades is that that they do not take up much space evenin the retracted position, making miniaturization possible.
The shutter of the Konica F, not yet unitized and still withguided linear blade travel, was considered to be still in its
infancy, and thus the Copal Square adopted in the Konica FS
released at substantially the same time is essentially said to be
the first mass produced. Figure 6-2 illustrates the configurationof each blade of the Copal Square. The shafts depicted bycheckered patterns in the figure are rotating shafts fixed to the68

The aperture is indicated by the dashed line. The figure
illustrates the state before shutter release, with the front bladegroup covering the aperture and the rear blade group in astandby state in the upper area. As illustrated in the figure, by
utilizing the parallel link, the two blades overlap in theretracted position, realizing a space-saving effect.
The principle of this mechanism was conceived by theinventor Chatani Kunju of the Kansai region and, according toanecdotes, he was inspired by the crossing barrier at a railroad
crossing. Chatani was also one who could not draw and soembodied the idea in a rough sketch and an enlarged modeland had an expert draw the drawing later1). Based on Chatani’s
invention, Copal developed the Copal Square, a unitized
shutter, selected Konica FS as the first installation, and thenstarted supplying the new product to each camera
manufacturer. This shutter structure was awarded the 1961
Akashi Memorial Award of the Japan Society of Precision
Engineering (currently the Japan Society for Precision
Engineering) under the joint names of Chatani and five Copal
engineers.
Many camera manufacturers, confused by the elevated levelof production technology and quality control required for inhouse focal-plane shutter production, turned to external
procurement, and thus this focal-plane shutter was adopted not
only in the Konica but also in Ricoh’s SLR cameras, the CanonEF, and Nikon’s intermediate camera brand, the Nikomat, andthe like.
This type of vertically traveling unit shutter rapidly became
widespread due to the advantage of a lower shutter price bymass production. Initially the new shutter was mainly adopted
in popular cameras, but with the advantages, in principle, of ashorter travel distance in the vertical direction of the frame,
allowing an increase in flash synchronization speed,subsequent miniaturization through blade configuration
ingenuity, improvements in the blade material, resulting inhigher durability and higher speed, and the intensification ofcompetition due to the entry of Seikosha, a company
strengthened by its lens shutter, the horizontally traveling
shutter started to be driven out in the 1980s and this new
shutter was adopted in many models. The technologicalevolution is described below for each element.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March(1) Higher speed

For a shutter, it is especially important to reduce the inertiaof the blades (curtains) that travel at high speed. For this reason,
various new materials were used in place of the original thinsteel plates. The Nikon FM2 extended the speed limit to
1/4000 by incorporating blades into the Copal shutter that weredeveloped by its own company and formed of a titaniummaterial thinned into a honeycomb shape by etching to reduce
the weight.

Photograph 6-3

Titanium Honeycomb Shutter Blades

Later, lighter aluminum alloys and plastics were adopted,
and currently some blades now use carbon fiber composites.
The blades are split into four or more in each group as standard,with some shutters having six. It became common to select thematerial for each blade in accordance with the amount of
movement and role of the blade, using the right material in theright place. These tireless improvements led to the ultra-highshutter speeds of 1/8000 in the Nikon F-801 released in 1988,
and 1/12000 in the Minolta α-9Xi released in 1992.
(2) Element improvement and miniaturization
While Copal focused on increased speed, Seikoshaprioritized miniaturization. The Pentax ME released in 1976
was declared the world's smallest and lightest Leica focalplane shutter SLR camera (at that time), thanks to the small
size of Seikosha's shutter, the Seiko MFC-E. This shutter isthoroughly miniaturized and simplified. For example, the coilwinding frame of the shutter control magnet is integrally
molded with the board frame to which other parts areattached2). This is shown in Photograph 6-4. This is surely askillful design by Seikosha's Nakagawa Tadashi, taking
advantage of the degree of freedom provided by plastic parts.

Photograph 6-4

Increasing the number of split blades makes the size morecompact, which makes it possible to reduce the size of the slitforming blades that move at high speed over a long distanceand thus reduce the inertia and increase the speed.
Inoue Nobuyoshi of Copal devised an epoch-making
parallel link structure that supports three or more split blades.
As illustrated in Figure 6-3, multiple blades are sequentially
imparted with a parallel link structure in positions near therotating shafts. This format became the basic configuration ofsubsequent Copal shutters, proving to be the company’s
moneymaker. At one point, this type was said to have a shutter
market share of over 50% and over 80% when including the
shutters made by other licensed companies. This configuration
created by Inoue received the 1985 Prime Minister's Invention
Award.

Figure 6-3 Copal’s Shutter Blade Support Structure(Japanese Examined Patent Publication No. 54-019175)(3) Other additional functions
An attempt was also made to improve performance byadding functions to the existing shutter.
The shutter balancer is a function built into Nikon's own
unit shutter, which was installed in the Nikon F4 released in
1989. This balancer is synchronized with the movement of the
shutter front blade group so that its momentum works in
opposition to that of the blade group, thereby mitigating theimpact of the jump of the shutter blade group. With themomentum of the shutter blade group being unexpectedly
large, tungsten alloy, which has an extremely high specificgravity, was used for this shutter balancer.

Mechanical Portion of the Seiko MFC-E

The Copal Square became Copal's blockbuster product, butthere was still room for improvement. The reason is that thelink structure that supports the blades was not yet optimized,
making it impossible to split the blades into a greater number.

Photograph 6-5

Shutter Balancer3)

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –69

The shutter became electrically controlled as the automatic
exposure system of the camera advanced. At first, the front
curtain was mechanically released and only the rear curtain
was electromagnetically controlled, but this method evolved touse magnets to control the respective operation start timings ofthe groups of blades in the front and rear. Often this was doneby changing the current to the magnets to release the attraction
force and free the iron core, but Canon developed a technology
of controlling the operation timings of the front and rear bladegroups by using a rotary magnet that does not have a magnetic
attraction surface, thereby preventing malfunctions caused bydust. The principle of the electrically controlled focal-plane
shutter will be explained in the next section on shutter control.
Shutters having split-type blades need to have a larger
overlap because of the risk of light leaking through the gaps
between the blades. This increases the inertial mass of theblades and hinders their ability to reach higher speeds, which
led to the development of the double-light-shielding
technology. In a normal state, the aperture is doubly blocked
by the front blade group and the rear blade group, and the rear
blade group is retracted at the start of release and then the front
and rear are moved to expose the image. Although theoperation is more complicated, the amount of overlap between
the blades is reduced because there is no longer any concern
about light leakage, which means that the inertial mass can besmaller, allowing for higher speed.
The accuracy and precision of the shutter speed may
deteriorate over time, but a shutter monitor function wasdeveloped as a countermeasure to this problem. This was firstmounted in the Nikon F5 released in 1996. An optical sensor
is placed to constantly monitor the shutter speed, and6.2

Automatic Exposure

The disadvantages unique to SLR cameras were overcome
with technologies such as the quick-return mirror and the fully
automatic aperture, and so the focus of development turned toautomation. In this section, we will discuss automatic exposure,starting with the evolution of the light metering system, aprerequisite.
6.2.1
Light Metering
One SLR camera with a built-in exposure meter is theKonica F, which uses selenium as the light-receiving elememt,
although it is an external light type. Production of this model
was short-lived, however, due to technical problems. Selenium
has the advantage of not requiring a battery because it
generates electricity based on the brightness of light received,
but has low sensitivity and requires a large area that spoils thecamera design and thus has only been used in a few SLRs, suchas the Canon RM.
Later, technological advances in light-receiving elements
led to the emergence of cameras that employ CdS
photoresistors that utilize a thin film of cadmium sulfide. CdS
has a resistance value that changes depending on the brightnessof the light received and therefore requires a battery, but its
metering performance was excellent compared to selenium.
The Minolta SR-7, released in 1962, had a built-in CdS on
the left shoulder, although it was an external light type.
Compared to selenium, CdS has a much wider dynamic range,
making it possible to measure light in dimly lit rooms. OtherCdS external-light cameras include the Canon FX and thePetriflex 7, but because the external-light system measures anamount of light that does not pass through the shooting lens, itdoes not take advantage of the key feature of the SLR, whichis the ability to observe the captured image as it is.

automatically corrects for any deviation in shutter speed. The
sensor also serves as a safety device to warn the user in theevent of shutter blade damage.

SensorRear bladegroup

Photograph 6-6

Minolta SR-7

(Provided by JCII Camera Museum)

Front blade
group

Before travel

Duringexposure

Travelcompleted

Figure 6-4 Shutter Monitor4)

70

The method of measuring the light of a subject through theshooting lens is called TTL (Through The Lens) metering.
TTL metering was naturally being considered by many
companies, but installation of the light-receiving element in
the imaging optical path interfered with the photographed
image or finder image and thus required ingenuity in terms of
the position of installation. Figure 6-5 illustrates the main
candidates for the installation position of the light-receiving
element in an SLR camera.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchare vapor-deposited, one for low brightness and the other forhigh brightness. This is the result of Toshiba's technology,
which is apparently related to the fact that Tokyo Opticalbecame a subsidiary of Toshiba in 1960. The mirror retracts
during shooting so that it is not in the way, and the metering
accuracy is good because the subject light does not passthrough the screen, making this arrangement close to ideal for
an SLR metering system. The technical hurdles of installing a
special light-receiving element pattern and a light-receiving
element in a moving section were high, and Tokyo Optical's
technological prowess in overcoming these difficulties andcommercializing the product is held in high regard.
Figure 6-5 Main Arrangement of Metering Elements

At Photokina in 1960, Asahi Optical exhibited a prototype
called the Pentax Spotmatic, which attracted much attention.
In this camera, the CdS sensor can be moved onto and awayfrom the screen (position B in Figure 6-5), and thus can be
moved out of the way during observation. Although thisarrangement is almost ideal for light metering due to theproximity of the element to the imaging plane, it is limited inprinciple to spot light metering, which measures only the partof the image where the light-receiving element exists, requires
a complicated mechanism for insertion and removal of thelight-receiving element and, most importantly, even thoughretractable, causes black shadows to be visible in the field ofview during observation, resulting in disfavor and an end withjust a prototype.
The first mass-produced SLR camera to offer TTL metering
was the Topcon RE Super released in 1963. This model was
the masterpiece of the SLR cameras of Tokyo Optical,
boasting many features in addition to metering due to thecompany's uncompromising application of its technologies.
The term “TTL metering” was first coined with this model.

Photograph 6-7

Topcon RE Super(Provided by JCII Camera Museum)

The head of the Design Department was Zenyōji Kenichi,
and the designers were Utsumi Kōzō and Kawase Suminosuke.
The light-receiving element was installed on the back side of
the mirror (position C in Figure 6-5) according to Kawase's
idea. There are other SLR cameras that use a “mirror meter”
with the light-receiving element placed here, such as the
Ricohflex TLS401, but they are extremely rare. As shown in
Photograph 6-8, there are groups of slits in a checked patternon the surface of the mirror, and light is transmitted throughthese slits only and metered by the CdS on the back of themirror. To take advantage of the large area, two types of CdSs

Photograph 6-8

Mirror Meter of the Topcon RE Super

The Topcon RE Super was a modern SLR camera designedby an American industrial designer at the request of a US
agency, but in terms of sales could not compete with the Nikon
F, which was already the reigning king of the high-end SLR
camera industry. Although Tokyo Optical decided to withdraw
from the camera business in the 1970s, its many outstanding
ideas and mechanisms as well as distinctive designs still shine
brilliantly in the history of 35 mm SLR camera.
The Pentax SP, the second best TTL metering camera, wasreleased in 1964. The metering method used in the prototype
for the Photokina exhibition was abandoned in favor ofmetering the screen projected image from both sides of theeyepiece (position A2 in Figure 6-5). Since the screen isviewed from a distance, spot metering has errors due to theeffect of the microprism in the center. For this reason, averagemetering, which averages the metered light across the entire
frame, was adopted.
Some models utilize a condenser lens near the screen forplacement of the light-receiving element. In the Canon F-1, asemi-transparent part is set diagonally near the center of thecondenser lens, and the reflected light is metered by a lightreceiving element next to the condenser lens (position G1 in
Figure 6-5). Although the accuracy is good because metering
takes place immediately after screen imaging, the periphery of
the frame cannot be metered in principle, resulting in partial
metering. Canon further developed this method and, in the
New F-1 released in 1981, a beam splitter was placed near thescreen to perform metering at position G2 in Figure 6-5.
The Minolta SRT101, released in 1966, adopted a split
metering system called CLC metering. This is achieved byplacing two light-emitting elements at position H in Figure 65, with one primarily metering the lower part of the frame andthe other primarily metering the upper part of the frame,
preventing measurement from being swayed by extremely

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –71high-brightness information, such as that of sunlight.

Photograph 6-9

Minolta SRT101(Provided by JCII Camera Museum)

Types that place the light-receiving element around theeyepiece, such as the Pentax SP, have some disadvantages
such as being readily affected by the aperture value and focal
length of the lens since transmission is through the lightdiffusing screen, and the possibility of exposure compensation
during screen replacement. However, with the light-receiving
element becoming increasingly smaller in size, such as CdS to
SPD (silicon photodiode) and GPD (gallium arsenide
phosphide diode), more and more cameras had the element
installed in position A1 or A2 in Figure 6-5, where there arefewer parts placed together, and this has become themainstream. In addition, the Pentax SP used average metering,but subsequently turned to center weighted metering, whichemphasizes the brightness near the center. This is because themain subject generally has a high probability of being near thecenter, and it is easier to follow the user's intention if theemphasis is placed there.
On the other hand, there are several variations of in-bodymetering, which is a method of metering in front of the screen,
like the Topcon RE Super.
Leitz, which had been defending its position as the lonestronghold of rangefinder cameras, released its first TTL SLR
to keep up with the times. This camera was the 1967 Leica Flex
SL. The camera is provided with a sub-mirror on the backsideof the original mirror (hereinafter referred to as “main mirror”)
to guide some of the light to position D in Figure 6-5. The
optical path through the semi-transparent section in the centerof the main mirror is reflected downward and metered by the
SPD element at the bottom. When shooting, the sub-mirror
moves about 135° and retracts together with the main mirror.
The Nikon F3 released in 1980 also adopted the sub-mirror
system (position F in Figure 6-5). In this model, a large numberof pinholes are placed in a portion of the main mirror insteadof the half mirror, which is prone to aging. In addition, withthe light-receiving element oriented slightly toward the film
surface, it can be used as a TTL light control element during
flash use.

Figure 6-6 Pinhole Mirror of the Nikon F35)

However, these sub-mirror systems had constraints in termsof the sub-mirror size, forcing the metering distribution to bepartial metering or close to partial metering, and took up more
space on the bottom of the camera with the AF (Autofocus)
elements as AF development progressed, and thus are nolonger seen today.
There are also methods of performing metering
immediately in front of the film surface. Although not an SLR
camera, the Leica M5, released in 1971, was the first in the
Leica M series to offer TTL metering. This camera features a
retractable light-receiving element installed immediately infront of the focal-plane shutter. The light-receiving element
emerges to enable metering when the film winding lever iswound, and retracts just before exposure after the shutter
release button is pressed. This is a straightforward metering
method typical of Leica, but the M5 had an unfavorable
reputation because of its uncomfortable size compared to theprevious M series cameras. Yet, this metering system wascarried over to the Leica CL. The Leica CL, released in 1973,
was sold under the product name Leitz Minolta CL only inJapan, and was a collaborative product designed by Leitz andmanufactured by Minolta. It was a monumental model createdthrough the technical collaboration between Leitz and Minolta,
but it was a bit of a departure from the orthodox Leica, withunique features such as a focal-plane shutter that used avertical-travel winding system like the Contax.

Photograph 6-10 Leitz Minolta CL(Provided by JCII Camera Museum)

Since the topic of the Leica CL has come up, I should
mention the metering system of its successor, the Minolta CLE.
In this model released in 1981, a large number of white dots
are printed on the front of the front curtain of the focal-plane72

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchshutter, and the light of the photographed subject reflected bythese dots is metered by a light-receiving element placed at thebottom of the camera. The shutter front curtain retracts during
the shooting operation, eliminating the need to provide amechanism for moving the light-receiving element in and out
as in the Leica CL. This is a very smart method, but there is aprecedent for it.
The Olympus OM-2, released in 1975, was the originator ofthis form of metering in which groups of white dots are printed
on the focal-plane shutter front curtain and metering is
performed by the reflected light (position E in Figure 6-5). The
disadvantage to the rangefinder camera is that, as an SLR
camera, metering is not possible when the mirror is in theobservation position (mirror down position). For this reason,
normal metering must be performed with a separate lightreceiving element installed near the eyepiece to display the
information. When the shooting operation is started, thecamera instantly meters the light after the mirror travels up anddetermines the shutter speed. The beauty of this method, called
direct metering, is that it truly measures the amount of light in
the image being captured in real time. When there isinsufficient reflected light from the shutter front curtain, thecamera accumulates the reflected light on the film surface after
the shutter opens, which in principle enables automatic
exposure even for long exposures of up to several tens ofseconds. Photograph 6-11 shows the shutter curtain of theOM10, a popular model in the OM series. The printing patternis changed for each model to optimize the photometricsensitivity distribution.

Photograph 6-11

Printing Pattern for Curtain Surface
Metering of Olympus

Further, the ancestor of the TTL light control of the flash
light previously described is the OM-2, and when the amountof reflection of the flash light from the film surface becomesappropriate, a signal is sent from the camera side to turn off
the light. In conventional flash photography, even thoughreferred to as automatic flash control, the flash is controlled by
the sensor on the flash side, and thus TTL light control
controlled through the actual shooting lens is remarkably
effective in close-up photography and greatly expands theshooting area.
The direct metering of the OM-2 was also developed by
Maitani Yoshihisa, the designer of the Olympus Pen F.
6.2.2
Multi-Pattern Metering
The Nikon FA, which was introduced in 1983, wasequipped with multi-pattern metering. The Nikon FA can
independently meter each of the five split areas of the frame.
Although the Nikon FA was sometimes labeled “the world's
first,” the origin of pattern metering was the Minolta SRT101
described in the previous section. However, at that time, it was
already commonplace to install a CPU in a camera, and the
Nikon FA was able to calculate the various pattern metering
information with a complicated algorithm to derive a more
optimal exposure value.
Pattern metering is performed by splitting the lightreceiving portion of the light-receiving element into areas,
arranging a lens in front of the light-receiving portion, andforming the screen image on the light-receiving element. In the
Nikon FA, as illustrated in Figure 6-7, two three-patternelements were used, but in principle one multi-pattern element
may be used.

Figure 6-7 Multi-Pattern Metering of the Nikon FA6)

The idea is that, if there is a high-intensity light source inthe vicinity of the frame, for example, the light source isregarded as the sun and predetermined exposure compensation
is applied. Nippon Kogaku initially analyzed the imaging dataof approximately 20,000 images to create an algorithm to findthe optimal solution. However, it is important to note that,when considering the question, “What is the proper exposure?,”there is no perfect answer as individuals often have different
preferences for high key (overexposed) or low key(underexposed) photography.
Multi-pattern metering subsequently evolved to increase thenumber of areas, with the Nikon F5 boasting an element with
1,005 areas in 1996. With the increase in the number of areas,
the light-receiving element, which was an SPD in the FA,
became a CCD in the F5, and in modern digital mirrorlesscameras, the imaging element itself can be utilized as the lightmetering element, making even an order of magnitude increasein the number of areas possible, in principle.
6.2.3

Full-Aperture Metering and Stop-Down
Metering
Although TTL metering with a metering element built into
the camera became possible, it created quite a troublesome
issue. With an SLR camera that realizes a fully automatic
aperture, viewfinder observation is basically performed withthe aperture open and so metering is also performed in thatstate. However, in actual shooting, the aperture is stopped
down to the set aperture value, and compensation must be

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –73

made for the difference.
One possible countermeasure is to stop down to the set
aperture value only during metering. This is called stop-down
metering. Although it is true that high accuracy is achieved
because metering is performed in the shooting state, it isannoying to have to stop down the aperture only during
metering after having achieved a fully automatic aperture thatmakes it possible to obtain a bright observation image. So,
naturally, a method of metering with the aperture value fully
open and then later correcting for the number of stops (thedifference between the open aperture value and the set aperture
value) was considered. This is called full-aperture metering.
Full-aperture metering is a perfect match for a fully
automatic aperture and TTL metering, but requires knowing
the number of stops of the lens in advance, which is not easy
with an interchangeable lens SLR. This is because the numberof stops is information on the lens side, which must be
communicated to the camera side. Until this point, designers
had their hands full with other things and had not given muchthought to the transmission of information between the camera
and the lens, so they had to think about adding a new system
to transmit information on the number of stops while taking
into consideration compatibility with lenses that had alreadybeen sold.
The first to adopt full-aperture metering was, again, theTopcon RE Super. In this camera, the aperture value ismechanically converted into information indicating thenumber of stops in the lens, and the camera receives thisinformation to realize full-aperture metering. Tokyo Optical
had obtained the rights to a powerful patent on this method,
and thus the manufacturers that followed had to obtain thelicense rights for use of this patent from Tokyo Optical. This
full-aperture metering method is also based on Kawase's idea.
Photograph 6-12 shows the area around the mount. The
aperture information lever receives the number of stops of thelens, and the aperture drive lever drives the aperture of the lensduring shooting.
Aperture
information lever

Aperture drive
lever

if the aperture value is the same, say F5.6, the correct exposure
value at the time of shooting is not known without knowing
whether the metering value (full-aperture metering value) at
the time of shooting is F1.4 or F2.8.
As a painstaking measure, Nippon Kogaku made it possible
to manually set the open aperture value when the lens ismounted. The Nikomat FT, an intermediate model, had a film
sensitivity setting dial where the open aperture value of theattached lens could be set manually, but the Nikomat FTn,
released in 1967, adopted a semi-automatic open apertureindexing mechanism commonly known as “click-clank.” With
this mechanism, when the lens is mounted on the camera, theaperture ring is first moved back and forth to engage the pinon the camera side with the “crab claw,” which is the lens
aperture information, and then rotated to the abutment on the
full-aperture side, automatically setting the open aperture,making use of the fact that the “crab claw” is always in theF5.6 position of the aperture ring. Though the mechanism wassemi-automatic, this elaborate method enabled Nikon SLR
cameras to use full-aperture metering with conventional lenses
as well, and also successfully avoided the Tokyo Opticalpatent.

Photograph 6-13

“Crab Claw” of the Nikon F

Other companies were also hobbled by mount restraints,
and Canon finally made full-aperture metering possible with
the Canon F-1, released in 1971, by revamping its signal
system and developing a new FD mount. The Canon F-1 wasa system SLR camera that took five years and a huge amountof development money to prepare as a competitor to the Nikon
F. With a wide range of accessories and lenses, the camera
caught up with Nippon Kogaku in the professional market andtook the official camera title from Nippon Kogaku for the firsttime at the 1976 Montreal Olympics. The camera in
Photograph 6-14 is the Montreal Olympics commemorativemodel.

Photograph 6-12 Mount Periphery of the Topcon RE Super

Nikon's SLR cameras, which had a fairly accurate outlook
on the future in terms of system performance, struggled withthis point. From the earliest lenses, each lens was equippedwith an interlocking “crab claw” to provide aperture
information. These claws worked well with external metering,
but when TTL metering became the norm, the lack of open
aperture information became a problem. In other words, even74

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchaperture value Av to be controlled is determined by Ev - Tv.
When promoting the use of automatic exposure in SLR
cameras, it was up to each company to decide which AE
method they wanted to use. A relatively substantial number ofmanufacturers started with aperture-priority AE, including
Nikon, Olympus, Minolta and Pentax. On the other hand,
Canon and Konica worked on shutter-priority AE. The reason
why aperture priority is of the majority is because the shutter
control required for aperture-priority AE is completed in the

Photograph 6-14 Canon F-1(Provided by Canon Camera Museum)

In Pentax SLR cameras, the M42 mount was a screw-in type,making positioning difficult, and the mechanical linkage wasstill challenging, but full-aperture metering was achieved in
the Pentax ES, also released in 1971.
Nippon Kogaku as well, not wanting to take second place
to competitors by staying with the “click-clank” mechanism,
bought the patent license for use from Tokyo Optical in 1977
and introduced an Ai system, which directly transmitted
information on the number of stops, and reformed the signaltransmission system between the camera and the lens. Typicalof Nippon Kogaku, they left the “crab claw” on the new Ai
lenses for compatibility and the conversion of old lenses to theAi system was accepted for over 30 years.

interior of the camera, whereas aperture control must be
applied to the entire interchangeable lens group, which islarger in scale. Canon was able to do this because it grasped
the necessity for aperture control in the future when thecompany switched to the FD mount in 1971.
(2) Shutter speed control
For aperture-priority AE, the shutter speed need only becontrolled to a speed corresponding to the set aperture value.
This can be achieved by starting the front curtain of the shutter
and then starting the rear curtain at a predetermined timing.
Figure 6-8 illustrates this principle.
Shutter release button

Rear curtain
drive spring

Front curtain

Rear curtain
Release switch

Aperture

6.2.4
Evolution to Automatic Exposure
The general formula expressing the exposure value Ev of a

Front curtain
drive spring
Front curtain
lock hookcamera is as follows:
Av + Tv = Ev = Sv + Bv
(Ev: Exposure value, Av: Aperture value, Tv: Shutter
speed, Sv: Film sensitivity, Bv: Subject brightness)

Front curtain
magnetControl circuit
Rear curtain
lock hook

Rear curtain
magnetFigure 6-8 Principle of Electronic Shutter

As easily understood from this equation, as long as film
sensitivity and subject brightness cannot be changed, theThe predetermined shutter speed is obtained by starting thefront curtain by unhooking it with the release of an iron piece

exposure value is determined by two factors: aperture value
and shutter speed. In other words, automatic exposure is afrom a magnet, and then disengaging the rear curtain based on
instructions from the control circuit.

technique that controls either or both the aperture value Av andthe shutter speed Tv for a certain desired exposure value Ev.

In early electronic shutters, the front curtain was started
mechanically, but there were also designs that picked up a start(1) Aperture-priority AE and shutter-priority AE

signal and then started the rear curtain based on electricalinformation (such as the amount of charge stored in a

To obtain a certain correct exposure value Ev, there are twomain methods: (1) setting the aperture value Av andcapacitor) corresponding to a predetermined shutter speed
converted from metering information.

controlling the shutter speed Tv, or (2) setting the shutter speed
Tv and controlling the aperture value Av. This means that

The Pentax ES was the first 35 mm SLR camera to beequipped with an electronic shutter, enabling automaticwhen the camera performs automatic exposure, a decision ismade as to whether to prioritize aperture value or shutter speed,

exposure control using TTL metering (for the external
metering type, the Konica Autorex, released in 1965, was theand the camera controls the remaining one. (1) is referred toaperture-priority AE, and (2) is referred to as shutter (speed)-first AE-equipped 35 mm focal-plane shutter SLR camera).
Also, as mentioned earlier, this camera is Pentax's first full-priority AE (AE stands for Auto Exposure). In a typical camera,
for aperture-priority AE, the exposure value Ev is obtained

aperture metering type with an interlocking claw and pin foraperture information with the M42 mount left as is.

from the subject brightness (metering value) Bv and the film
sensitivity Sv, the aperture value Av is determined by thephotographer, and thus the shutter speed Tv to be controlled isdetermined by Ev - Av. Similarly, with shutter-priority AE, theSystematic Survey on 35 mm High End Camera – History from Leica to SLR –75

designed K mount, simultaneously releasing the Pentax KX,
K2 and KM to promote the new mount. In particular, the K2
was an ambitious camera equipped with the newly designed
electronically controlled unit shutter, the Seiko MF, jointly
developed with Seikosha. Normally, a major mount change is
a risky move for a manufacturer, but Asahi Optical managed
to release not only three models, but also a large number ofinterchangeable lenses at the same time and included
Photograph 6-15 Pentax ES(Provided by JCII Camera Museum)

automatic exposure advancements as well, successfully
breaking through the shackles of the M42 mount.

Shutter control for aperture-priority AE can be achieved
relatively easily with just an electrically controllable shutter
and a circuit for storing metering information, and thus a
number of manufacturers adopted this method.
With the Nikomat EL in 1972, Nippon Kogaku achieved its
first aperture-priority AE as a 35 mm focal-plane shutter SLR
camera.

Photograph 6-18 Pentax K2(Provided by JCII Camera Museum)(3) Aperture Control
The aperture is located on the lens side, making controllingthe aperture in the same way for all interchangeable lenses
from the camera side more difficult than shutter control. In
Photograph 6-16 Nikomat EL(Provided by JCII Camera Museum)

Minolta similarly entered the automatic exposure SLR
camera market with the Minolta X-1 in 1973. This model wasa high-end professional model with an interchangeable
viewfinder, and adopted aperture-priority AE. At the time,
there was still a deep-rooted belief that using automatic
exposure was somehow unprofessional, making this arevolutionary camera in that sense.

contrast to shutter control, which is achieved substantially byno other strategy than electrical control, aperture control can
be classified into several forms. The following is an
explanation according to classification.
(1) Meter needle holding method
To achieve a fully automatic aperture, stopping down thelens from the camera side via an interlocking mechanism wasalready being done by the SLR cameras of various companies.
For example, when Canon changed to the FD mount, theaperture value was transmitted by the aperture information
lever on the inside of the mount on the camera side, and theaperture on the lens side was stopped down by operating theseparately installed aperture drive lever. In other words, thedesired aperture value can be obtained by controlling theamount of movement of the aperture information lever (on thecamera side) by some means.

Photograph 6-17 Minolta X-1(Provided by JCII Camera Museum)

Asahi Optical, which was the first company to convert to
AE with the Pentax ES, had managed to survive to this pointwith the M42 mount, but sensed its limitations with the small
mount bore, the hassle of mounting and the like, andabandoned the M42 mount in 1975 and shifted to the newly

76

Therefore, the method used in lens-shutter compact cameras,
which utilizes the movement of the meter needle to indicate
the exposure value, was adopted in SLR cameras as well.
Because the amount of movement of the lever to be stopped
down corresponds to the exposure value obtained as a result oflight metering, this can be directly read as position information
and reflected in the aperture value. This is the principle behindthe meter needle holding method. The Canon EF, released in
1973, was Canon's first shutter-priority AE SLR camera that

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchdisadvantages, the former being better for emphasizing depthof field and the latter being better for expressing the movementof the subject. However, in the early days, SLR cameras were
equipped with only one or the other, and naturally, there were
expectations that a model with both would eventually appear.

used this method.
The principle is illustrated in Figure 6-9.

Having both capabilities is referred to as “dual-priority AE,”and the first SLR camera with dual-priority AE was the
Minolta XD in 1977 (called Dual AE by Minolta). Because
Minolta started with aperture-priority AE, the company
adopted a unique method to incorporate the aperture control
necessary for shutter-priority AE. This is the instant stop-down
method.

Figure 6-9 Meter Needle Holding Method

The operation is performed in order from arrows A to G.
The following is a step-by-step explanation.
(1) When the shutter release button 1 is pressed indirection A, the slide lever 2 moves in direction B.
(2) The stepped lever 3, which was restricted by thesliding lever 2, starts to rotate in direction C.
(3) This causes the meter needle holding plate 4, which
is linked to the stepped lever 3, to move in
direction D.
(4) The needle 5 of the exposure meter is positioned inany position in the guide plate 6 according to thebrightness of the subject.
(5) The meter needle holding plate 4 holds the needle 5
and stops at a height corresponding to its position.
(6) Meanwhile, the slide lever 2 is pressed further
downward, and the locking hook 7 starts to rotate
in direction E.
(7) Engagement with the locking hook 7 is released
and the aperture drive lever 8 starts to rotate indirection F.
(8) At this time, the aperture drive lever 8 is limited by
the position of the step of the stepped lever 3.
(9) In other words, the position of the needle 5 of the
exposure meter determines the position of theaperture lever 8.
(10) As a result, the position of the aperture lever 9 of
the lens 10, which is pressed in direction G by theaperture lever 8 is determined, and the aperture iscontrolled at the aperture corresponding to the
exposure meter (exposure value).
The meter needle holding method was used in early SLR
cameras because of its relatively simple configuration, but theforce required in pinching the delicate meter needle and thelong shutter release button stroke were disliked, and the system
was gradually replaced by other methods.
(2) Instant stop-down method
There was a debate about which was best, aperture-priority
AE or shutter-priority AE, but with even a little knowledge ofphotography, it is obvious each has its advantages andPhotograph 6-19

Minolta XD(Provided by JCII Camera Museum)

When the shutter release button is pressed, the aperturelever starts to operate and the lens is gradually stopped down.
In association, the amount of light traveling to the lightreceiving element on the camera side also changes from brightto dark. The light intensity value is measured in real time, andthe aperture lever is stopped when the desired value is reached.
Because of this principle, the instant stop-down method is also
referred to as the light intensity feedback method.
For manufacturers like Minolta and Nippon Kogaku, who
had to start with aperture-priority AE, the amount of
movement of the lens aperture drive lever and the actual
amount of aperture reduction differ from lens to lens. For
example, with lens A, moving the aperture lever by 3 mm
results in a 3-stop reduction, but with lens B, the same 3-mmmovement only results in a 2-stop reduction. This is because
the time when the system was created was so long ago thatdesigners did not take aperture control into consideration at all,and companies postponed changing the system out ofconsideration for users with conventional lenses. In this regard,
the instant stop-down method feeds back the light intensity as
it is, not the amount of movement of the aperture lever. This
was Minolta's painstaking strategy to avoid this problem. The
XD was a hit because of its dual-priority AE feature andcompact, lightweight body that was easy to operate, but the
instant stop-down method had a fundamental disadvantage.
Metering needs to be done at all times during the lens
aperture operation, and the mirror needs to remain in position
during this time. This is because raising the mirror cuts off thelight to the light-receiving element. In other words, the mirror
was raised simultaneously with stop-down, but now had to beraised after stop-down. Because both mirror lock-up and the

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –77aperture drive require about 20 to 40 ms, the shutter time lag,which is the time between pressing the shutter release button
and actual exposure, becomes longer, which may result in
missed shutter opportunities with moving subjects.
Nippon Kogaku, which was in the same position as Minolta,
adopted the instant stop-down method for its Nikon FA, FG
and others, but later, as automatic winding was developed andhigh-speed continuous shooting became more important, thistime lag problem gradually emerged, and both Minolta andNippon Kogaku were forced to switch to new lens systems.
(3) Stop-down amount feedback method
Aperture control refers to controlling the aperture lever on
the lens side in an appropriate position from the camera side,and thus the aperture lever can be controlled at any position by
converting the position information into electrical information
and reading the electrical information. Canon, which started
automatic exposure with shutter-priority AE, worked
diligently to develop this method and introduced it in theCanon AE-1 released in 1976.
This model was an unprecedented hit due to the introductionof a full-fledged CPU (microprocessor) into the SLR and thelow price achieved by advancements in automated production.
The aperture control also adopted a resistance value feedback
method in which the stop-down amount, that is, the amount of
movement of the aperture lever, is converted into a resistancevalue for control. The introduction of the CPU maximized theadvantages of being able to control each mechanism in thecamera in parallel and instantaneously.

Photograph 6-21 Canon A-1(Provided by Canon Camera Museum)The digital value feedback aperture control method would
later become the standard for SLR cameras, and would be usedby Nikon as well, especially in professional cameras wheretime lag was critical. As an example of this type of aperture
control mechanism, the mirror/aperture control mechanism of
the Nikon F5 released in 1996 is shown in Photograph 6-22.

Photograph 6-22
Mirror/Aperture Control
Mechanism of the Nikon F5

Photograph 6-20 Canon AE-1
(Provided by Canon Camera Museum)Two years later, in 1978, Canon introduced the A-1, whichused digital processing to control everything in the camera.
The aperture control is also more advanced than the AE-1,
adopting a digital value feedback method that converts theaperture value into a digital value for control. Although the A1 fell behind the Minolta XD as a dual-priority AE SLR, theA-1 was an extremely complete and innovative camera.

78

This mirror/aperture drive system mechanism performs allof the functions of shutter release, mirror drive and aperture
control. The aperture control mechanism alone can be
described as follows.
(1) The aperture start solenoid 1 is activated, rotating
the aperture lever 3 clockwise to initiate stopping
down. Although not shown in the photograph, 3 islinked to the aperture lever on the lens side.
(2) The movement of the aperture lever 3 is increasedin speed by the acceleration gear 4, rotating theratchet wheel 5 provided with many holes.
(3) The photocoupler 6 counts the number of holes in
the passing ratchet wheel 5.
(4) When the count (which corresponds to the aperture
value) reaches a predetermined value, the aperture
stop solenoid 2 is activated and the aperture stops
at the predetermined value.
Such a process as described above is used to control theaperture to a predetermined value. Note that 8 is the gearsystem for eliminating gear system backlash, and 7 is thesolenoid for shutter release. Along with the aperture control
mechanism, I think you will easily understand the modern

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchdrive system that uses solenoids and other dedicatedelectromagnetic actuators for various movements.

Speed, which was based on the Nikon F and could shoot at 7
fps with the mirror locked up, was released as a model tailored
toward the press. This model was for the Sapporo Winter6.3 Automatic Feeding

Olympics, and a special external viewfinder was provided forOnce advancements in exposure automation were made anduse with the mirror raised.

accepted by the market, the next step was to develop automatic
feeding technology that automates film winding. This socalled accessory is called a motor drive or a winder. Generally
speaking, the accessory is called a motor drive if thecontinuous shooting speed is fast, and a winder if thecontinuous shooting speed is slow, but the boundary between
the two is not clear. My sense is that it is the former if the speed
exceeds 2 fps (frames per second), and the latter if the speed isless than that or if the shooting is single-frame shooting only.
6.3.1

Motor Drive

Automatic film feeding itself has been around for a longtime, and Nippon Kogaku, which had been used by the press
for its high reliability, had offered a mountable motor drive
device since the advent of its rangefinder cameras as a special
specification. Even the Nikon F, although requiring someadjustment, could be retrofitted with a motor drive. For
professional applications, most of the high-end SLRs of eachcompany established motor drive specifications, such as theCanon F-1 released in 1971. Minolta also released the X-1
Motor in 1976, which combined a motor drive with the X-1
professional model. Nippon Kogaku also released thesuccessor to the F, the F2, in 1971, with enhanced motor drive
functions and a faster continuous shooting speed of 5 fps.
High-speed continuous shooting became a great advantage,
especially in the field of sports photography.
In order for a motor drive and a camera to work organically,
the interlocking system needs to be optimized. Early models,such as the Nikon F2, used a coupling for winding and a “prod”

Photograph 6-23 Nikon F High Speed7)

Canon, which was planning to penetrate into theprofessional market, was also keen to improve the continuous
shooting speed and launched the F-1 High Speed Motor Drive
Camera in 1972 for the Munich Olympics. In order to increase
the speed, Canon abandoned the mirror drive that requires along operation time, and adopted a fixed semi-transparent
pellicle mirror and made the aperture manual. In addition, themetering function and low shutter speed were omitted toachieve a maximum speed of 9 fps. The camera, shown in
Photograph 6-24, receives power from an external battery packof 20 AA batteries via a cord.

for the shutter release as a mechanism. At that time,mechanical shutter releases were used, so the only way torelease the shutter from the motor drive side was bymechanical means such as a prod. Because there is no signal
from the camera side to end exposure, the camera is forced tostart winding in expectation of the end of exposure, resulting
in a risk that winding will start during exposure at low shutter
speeds. Therefore, a setting dial is provided on the motor driveside to determine the timing of the start of winding inaccordance with the shutter speed of the camera. The motor
drive system of the Nikon F2, although prehistoric now, wasadvanced at the time, including automatic film rewinding, andwas used by many news photographers at the Olympics andPhotograph 6-24 Canon F-1
High Speed Motor Drive Camera(Provided by Canon Camera Museum)other events.
The need for high-speed continuous shooting by the news
media was understood from early on and, in 1971, the F High

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –79

In 1978, Nippon Kogaku also released the F2H with a fixedsemi-transparent mirror, surpassing Canon with 10 fps.
However, the race to increase speed in this era had limitationsin terms of general photographic performance, such as
metering, the prices were extremely high, and many products
were sold only to the press, resulting in models that had little
to do with general photography enthusiasts.

Photograph 6-26 Canon F3 + MD-4 Motor Drive9)

Canon came out with the New F-1, the successor to the F-1,
in 1981. The position of the motor drive for this camera isunique. The aperture control mechanism is on the motor driveside and shutter-priority AE is enabled with the mounting of
the motor drive. The design was based on the idea that, withthe shooting prioritizing shutter speed, continuous shooting isrequired, but was intriguing as a new motor drive concept.

Photograph 6-25 Nikon F2H(Provided by JCII Camera Museum)In the 1980s, the electric shutter release became morecommon, making it possible to release the shutter by anelectric signal rather than mechanical means such as a prod. At
the same time, necessary signals such as the shutter rear curtain
signal (for timing the completion of exposure) could now be
exchanged by simply installing electric contacts. Finally, theera was now one in which ordinary amateurs could benefit
from high-speed photography with almost no restrictions.
The race for faster motor drives between the top two
manufacturers, Nikon and Canon, in the high-end professional
camera market continued with the Nikon F3 and Canon New
F-1. In the Nikon F3 released in 1980, the camera's winding
mechanism and shutter mechanism were redesigned, and ballbearings and other components were used in abundance toreduce the winding torque. This was partly to improve the feelof the original winding lever, but according to Satō Akihiko
and others in charge of the design at the time, motor drive
acceleration and energy saving were also in mind.8) Indeed, theMD-4 motor drive for the F3 can achieve 5.5 fps with adedicated NiCd battery, or 6 fps with the mirror lock-up,
without requiring any special modification. Additionally, theMD-4 consumes relatively little battery power.

80

Photograph 6-27 Canon New F-1 +AE Motor Drive FN10)

The fastest continuous shooting speed for a 35 mm SLR is
14 fps, which was achieved by the Canon New F-1 High Speed
Motor Drive Camera released in the 1984 Olympic year,
combining the special technology of the fixed pellicle mirror
and a special horizontally traveling, electromagneticallydriven metal blade shutter. This camera was extremely large
due to the use of a special 24 V battery and was sold in limited
quantities for 1.3 million yen, but there was a certain demand
for the camera for sports photography.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchSince then, SLR cameras, including those for professional

the bottom, a very reasonable layout indeed.

use, have been equipped with built-in motor drives rather than
external ones, and the use of AF has advanced. Even though
the playing field changed, the rivalry between the two leadersin the professional line, such as the EOS-1 series and the Nikon
F5, continued for a long time.

Figure 6-10 Topcon Super DM + Winder Structural
Drawing11)

The rapid spread of winders began with Canon's blockbuster,
the AE-1. The AE-1, also known for its full-fledged built-in
CPU, was well received for its high functionality andreasonable price. In fact, Nippon Kogaku released the ELW
and the AW-1 winder based on the Nikomat EL a few months
Photograph 6-28 Canon New F-1 High Speed Motor
Drive Camera(Provided by Canon Camera Museum)

6.3.2

earlier than the AE-1. However, the AE-1 was priced at 81,000
yen with a 50/1.4 lens, while the Nikomat ELW was priced at
the same for the camera only, so it was far behind the AE-1 interms of sales (the price in Photograph 6-29 is 85,000 yen, butthat includes the case). In addition, most of the advertising wasdone with the Power Winder A attached, and even the sound of

The Winder

In addition to the motor drive for high-speed automatic
feeding for professionals described above, there is a type of
automatic feeding called a winder. The winder evolved
because, even in general amateur photography, automatic
winding reduces the probability of missing the moment to takea photo and, first and foremost, increases convenience. If we

continuous shooting was played in the TV commercials. The
Japanese catch phrase “Rensha-ichigan (continuous shooting
SLR)” shown in Photograph 6-29 had a strong impact on themarket, and the term “Rensha (continuous shooting)” waspopularized by this camera.

go back in time, Leica had offered a spring-loaded automatic
winding accessory and, in Japan as well, the Ricoh Auto Halfand the Canon Dial 35, which were not SLR cameras,
automated most of the functions of the camera, including film
winding with a spring, making the models huge hits. Although
it would be difficult to use springs in SLRs requiring a lot ofenergy to charge, the availability of compact, highperformance motors brought the wave to the SLR.
If you trace the origin of the winder for the SLR, you willfind that it is once again a Topcon product. The aforementioned
Kawase, after realizing TTL metering and full-aperture
metering with the Topcon RE Super, thought that the next stepin automation would be easy film feeding and decided toincorporate it in the successor. Tokyo Optical, with its trackrecord of delivering motor drive devices, albeit in large scale,used that know-how to launch the Topcon Super DM for thegeneral amateur market in 1973.
It was probably with this camera that the term “winder”
became commonplace. The special winder that comes standard
with the camera has a grip, the winding motor is placed inside

Photograph 6-29 Canon AE-1 Advertisement(Provided by Canon Camera Museum)

Since 1976, when the AE-1 was released, the most popular
SLR cameras have been equipped with winders as optional
accessories.

the grip, and four AA batteries are positioned side by side at

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –81

6.3.3

Emergence of SLRs with Built-in Automatic
Winding Function

As motor drives and winders became more common, it was
natural for companies to consider integrating motors intocameras for film winding. In the following, I will describe thehistory of this technology, but first, I would like to note that,in a broad sense, the Minolta X-1 MOTOR, SR-M and the likealso have motor drives that cannot be removed, so one could
argue that these cameras have built-in motors. However, froma technical point of view, the cameras are considered to be“integral” models with a fixed external motor drive, not a“built-in” motor drive. The following, therefore, describes
cameras with an internal motor drive, such as the Konica FS1.

the conventional so-called “sprocket drive” mechanism, was a
visionary move, considering the fact that cameras with builtin motors have since moved in that direction.
Power supply is a major issue for a camera with a built-in
motor, but in the FS-1, four AA batteries were placed in thegrip, improving the grip feel as well. Furthermore, to takeadvantage of the automatic winding system, accessories suchas a wireless release device for shooting from a distance, aninterval timer for cyclic shooting and a left-hand release button
were also provided.
CPU control, which became mainstream with the Canon
AE-1, was also incorporated to enable the well-timed controlof three motors, including those for winding and drive systemcharging, and four solenoids for triggering each function.

(1) The Konica FS-1
At Photokina in the fall of 1978, a prototype of an SLR withan eccentric design was exhibited. The following year, in thespring of 1979, Konishiroku Photo Industry released this as theKonica FS-1, a 35 mm SLR with a built-in motor andautomatic winding system.

The FS-1 was thus the ambitious work of Konishiroku
Photo Industry, but it was not a success in terms of sales. There
are various speculations about the cause of the unpopularity of
the camera, such as malfunctions due to motor noise affecting
the CPU, loading problems due to variations in film rigidityand difficulties in repairing the complicated winding
mechanism. However, in my opinion, the reason was that thecontinuous shooting speed was too slow at about 1.5 fps(catalog data; the performance seemed much slower), eventhough the camera was deliberately equipped with four AA
batteries. Even cameras with manual winding can shoot fasterthan that once the user becomes familiar with the mechanism.
Also, despite the fact that automatic film loading was a very

Photograph 6-30 Konica FS-1
(Provided by JCII Camera Museum)

Konishiroku Photo Industry released a practical lens-shutter
camera with a built-in flash, the Konica C35EF (nicknamed
the Pikkari Konica in Japan) in 1975 and the world's first
automatic focus (AF) camera, the Konica C35AF (nicknamed
the Juspin Konica in Japan), in 1977, both of which became
major hits, but Konishiroku Photo Industry took a backseat as
an SLR manufacturer. This FS-1 model was to be their quick
comeback, with a built-in film winding function and an
attempt to automate the film loading process. The name “FS,”which stands for Future System, also conveys their enthusiasm.
Technically, the motor was placed inside the film winding
spool to increase space efficiency, and a differential
mechanism was cleverly incorporated to wind the film andstop the winding. In conventional cameras, the sprocket feeds
the film for a predetermined length (8 perforations = 38 mm)
and then the spool rewinds it, but in this camera, the spool
winds the film and the sprocket just counts the perforations.
The adoption of the “spool drive” mechanism, as opposed to82

beginner-friendly specification, the price may have been illmatched for the amateur. Konishiroku Photo Industry released
a successor model, the FT-1 Motor, to break the slump of thismodel, but it too failed to make a splash and, at that point, thecompany gave up on the SLR market.
(2) The challenge of automatic winding for the Yashica
ContaxWhen Konishiroku Photo Industry exhibited the FS-1 at
Photokina in 1978, a slightly unusual model without a winding
lever was also displayed at the Yashica booth. This was theContax 137MD Quartz, the second automatic winding SLR
with a built-in motor.
The name Contax abruptly appears here, and this requires
an explanation. To digress a bit, as mentioned earlier, Zeiss
Ikon misjudged the main battlefield of SLR cameras andmissed the trend by launching the Contaflex with a lens shutter
and the ultra-high-priced Contarex, and withdrew from camera
production in 1971 to concentrate on the production of camera
lenses. However, the company could not deny their SLR

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchambitions, and was looking for a way to collaborate with a

The premier specification, automatic winding, was also

Japanese camera manufacturer that was gaining momentum.

equipped with interesting technology. In the Konica FS-1,

Asahi Optical, who was approached first, turned down theoffer, but Yashica, who was next in line, gladly accepted.
Yashica was languishing as a popular manufacturer of SLRs,
and thought that it needed the prestigious Contax brand to
expand into high-end models. Then, in 1975, the Contax RTS
was sensationally released.

independent motors were used to operate the mirror, shutter
and aperture, feed the film and charge the mechanism system,
but in the 137MD Quartz, only one motor was used to do allof these things. By making good use of a one-way clutch, theforward rotation of the motor after release causes the aperture
to stop down, the mirror to rise and the shutter to travel, andthe same motor is reversed after shooting to reset the drive
system and wind up the film. The design saves space byrequiring only one motor, and improves motor efficiency by
avoiding the concentration of drive torque. In the case ofcameras, quick operation is desired, so core-less motors withgood responsiveness are the best choice, but they are
expensive. This camera only requires one motor, resulting in acost advantage.
Although the mechanism is complex with its clutches andinterlocking systems, the 137MD Quartz was well organizedPhotograph 6-31 Contax RTS

as a camera, with a continuous shooting speed of up to 2 fps(Provided by JCII Camera Museum)As an SLR compatible with Carl Zeiss lenses, this camera
became a temporary threat to Nikon and Canon in theprofessional market. Then, the 137MD Quartz was exhibitedat the same time as the Contax 139 Quartz at Photokina in 1978
as an intermediate model that could use these same lenses. As
the name implies, the 139 Quartz was the world's first SLR
camera to use quartz as the oscillator for timer control of the
shutter speed and the like, and was released in April 1979.
A year and a half after its Photokina debut, the 137MD
Quartz was released in May 1980, a year after the manually
wound 139 Quartz. It is assumed that production difficulties
were due to the complexities inherent in SLRs with built-in
motors.

and a more comfortable feel than the FS-1. The camera wasconsidered to be positioned as an aperture-priority AE model
more for the amateur but, in 1982, was succeeded by the
137MA Quartz, which enabled manual exposure and increased
the continuous shooting speed to 3 fps, surpassing the external
winder models. This series continued until the 167MT in 1987,
offering automatic rewinding capabilities and the world's first
auto bracketing (automatic multi-step exposure) function that
automatically captures three frames with different exposures,
including a correct exposure, slight under exposure, and aslight over exposure. Yashica (merged with Kyocera in 1983)
was to be commended for the reliability of its initial design of
the automatic winding function and its technical ability tosuccessfully evolve the function, but the only stumbling block
was AF support.
The Contax automatic winding camera exhibited at
Photokina in 1982 also had a built-in AF drive function. This
prototype, based on the 137MD, is said to have alreadyadopted the method that Minolta later used to astonish theworld with the α-7000, in which the lens focusing is performedby an AF lens drive motor built into the camera side. However,this prototype never made it to the market. Then, in thesubsequent AF SLR era, the company was not blessed with

Photograph 6-32 Contax 137MD Quartz

any hit products and completely withdrew from the camera(Provided by JCII Camera Museum)

Back to the topic at hand, the 137MD Quartz represented,

business, but that story will be covered in a later section.

in many ways, a stark contrast to the FS-1. First of all, thearranged position of the batteries was quite different. In
contrast to the FS-1 with the batteries standing in the grip, fourbatteries were placed at the bottom. Most likely the company
did not want to destroy the Porsche design image of the Contax
RTS already put forth. Indeed, it is just a little bit taller, andcan carry on the design without any discomfort.
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –83

(3) Canon T series
Canon, which established an era of auto-exposure SLRs

falling short of the α-7000, a full-fledged AF SLR introducedby Minolta the same year.

with the AE-1 and the A-1, was also keenly aware of the
movement toward automatic winding and had been searchingfor a new concept since the early 1980s. This was realized with
the T series. A new design concept was adopted for the exterior,and automation, including film winding, was accelerated. The
first of these was the T50, released in 1983. Each camera of
the T series has its own nickname, and the T50 was named“Automan” in Japan. This was probably due to the tremendous
success of Sony's “Walkman” in the late 1970s.

Photograph 6-35 Canon T80(Provided by Canon Camera Museum)In 1987, the T90 appeared. Canon released the T-series
cameras in quick succession, each with its own uniquecharacteristics, but the T90 drew attention for its design. The
ergonomic appearance, said to have been designed by Luigi
Colani, an industrial designer famous for his curved and avantgarde works based on biological and natural motifs, had astrong impact both visually and in terms of operation feel.

Photograph 6-33 Canon T50(Provided by Canon Camera Museum)

The T50 was a popular camera that only had program AE.
Since automatic winding was still in its infancy, the intention
was most likely thorough automation for beginners, i.e., an
SLR version of a fully automatic compact camera.
This camera was followed by the release of the T70 in 1984.

Photograph 6-36 Canon T90

Its nickname was the Intelligent Shooter. In order to achieve(Provided by Canon Camera Museum)thorough automation and multifunctionality and prevent thatmultifunctionality from leading to complicated operations, a

The UI, which was a further development of the T70 UI andnew concept was applied to the user interface (hereafter UI),

used two control dials and a large LCD display, was also aand information input using a large LCD panel and pushprecedent for later cameras. The internal mechanism wasbuttons became a hot topic. This UI adopted by the T70

extremely advanced as well, using three motors to increase

remains the standard method today, even in the digital camera

speed. The T series ended with this model because of theera.

failure of the T80 to support AF, and so Canon changed thelens mount completely to transition to the EOS series, whichprioritizedAF

support.

However,therevolutionary

specifications and design concept of the T90 were inherited fora long time by the next generation, and had a profoundinfluence on other companies.
In this way, it can be said that Canon's characteristic policy
during this period was to reconstruct the product concept,
including the design, rather than simply aim for automatic
Photograph 6-34 Canon T70(Provided by Canon Camera Museum)winding specifications.
Incidentally, the nickname of the T90 was “the Tank.” The

In 1985, a year after the release of the T70, Canon's first AF

TV commercial was impressive. The head of a robot appeared

SLR, the T80 (nicknamed the Art Robo) was released. Thison another planet and opened up, and the T90 inside it started

was a complete SLR camera with auto exposure, auto winding

continuous shooting.

and autofocus (AF), but was not a hit because its AF
performance, a crucial feature, was not yet up to the mark,84

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

(4) Relationship between other company motor built-in

such as NiMH (nickel metal hydride) and lithium-ion batteries,
were developed. This trend extended to professional SLRs as

models and AF models
As understood from the fact that the Canon T80 is an AF
camera, the tide toward AF was about to turn in the 1980s. The

well, and models such as the Nikon F4 and the Canon EOS-1
were released in 1989 as models with built-in motors.

trend was for companies to try to achieve built-in motors alongwith AF. Minolta worked on the development, even including
a major change in the lens mount, to make the trend toward AF
blossom at once. The Minolta α-7000 was the first of its kind,and this model and the AF models that followed it will be
discussed in detail in the later section on AF.
Olympus' first SLR with a built-in motor was also an AF
model, the OM707. AF cameras almost inevitably came toinclude a built-in motor, making it natural to incorporate
automatic winding as well.

Photograph 6-38 Canon EOS-1

Somewhat different from Minolta and Olympus, Nippon(Provided by Canon Camera Museum)

Kogaku seems to have intended to release an automatic windermodel with a built-in motor before the AF model. It is wellknown that Nikon had been seeking a camera with a built-in
motor from early on, as indicated by a special exhibition at the
JCII Camera Museum12) and a special exhibition at the Nikon
Museum, “Prototype Cameras – Developers' Memories.” In1985, Nikon's first SLR camera with a built-in motor, the F301, was released based on a prototype model with a built-in
motor, tentatively called the MDX, although it was not an AF
camera. At that time, Minolta had already released the AF α7000, so Nippon Kogaku could not deny that they were late to
the party, but this camera was actually a milestone for the

Photograph 6-39 Nikon F4

coming AF era.

(Provided by JCII Camera Museum)With multiple motors arranged in the right places, eachmechanism became more efficient and unitized, making thecamera smaller, lighter, faster and more energy-efficient thanthose with an external motor drive, which led to the rapid
spread of this technology to various genres including that forthe press.
In 1996, the Nikon F5 was released for the Atlanta
Olympics, and was capable of high-speed continuous shooting
at 8 fps. I was in charge of the development of this model, andfelt that we were approaching the limit of what could be

Photograph 6-37 Nikon F-301

achieved without special modifications for high speed. Canon(Provided by JCII Camera Museum)achieved 9 fps with AF tracking and 10 fps without AF
tracking with the EOS-1V released in 2000, but in the prior(5) Use of built-in motors in professional models

year, 1999, Nikon released the D1, a full-fledged digital SLR

The shift to AF in SLR cameras, which began in the mid1980s, accelerated almost in parallel with the introduction offor professional use, and the silver halide era was coming to anend, especially in the press.

built-in motors. AF will be discussed in a later section, but I'dlike to note the subsequent evolution of models with built-in
motors.
The performance of cameras with built-in motors improved
dramatically since the latter half of the 1980s as motors
became more efficient, smaller and less expensive, and asrechargeable batteries having better performance than NiCd,
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –85

The concept was to banish the “three evils” of the SLR: size,
weight and shock.
At 136 x 83 x 50 mm and 510 grams (body alone), thecamera was only two-thirds the size (by volume) of an average
conventional SLR. The width of 136 mm is the same as that of
the Leica IIIf. Maitani said, “The size is not a simple copy of
the Leica; it had to be that size.”13) However, I believe that theMaitani was aiming for the size of the Leica IIIf from the start.
Maitani used the Leica IIIf on a daily basis, and when Leitz,
Photograph 6-40 Nikon F5(Provided by JCII Camera Museum)

who had already released an M series, complained about thename M-1, Maitani immediately accepted Leitz's demands andchanged the name to OM-1, which seems to show respect for
the Leica.
Aside from that, taking into consideration compact andlightweight technology, Maitani started by revamping theentire layout. In conventional SLRs, the shutter dial was
positioned on the left shoulder, but Maitani gave that prime
location to the film sensitivity dial. This change was made inorder to place the large exposure meter inside the film
sensitivity dial, making efficient use of space. This position is

Photograph 6-41 Canon EOS-1V(Provided by Canon Camera Museum)

6.4 The Trend Toward Miniaturization

The following is a brief history of the trend toward smaller
and lighter SLR cameras that began in the early 1970s.
6.4.1

Birth of the Olympus M-1

Belatedly, in 1972, after a long and vigilant development
process to enter the Leica format SLR market, Olympus finallylaunched the M-1. Unlike the FTL, which succumbed toright next to the pentaprism, making it convenient to bring themeter needle into the viewfinder. He then placed the shutter
mechanism under the mirror box. Conventionally, a governor
for low speeds or the like was placed in this position, but withthe shutter mechanism now concentrated here, the need forlinkage was eliminated. This led to the use of a ring provided
at the base of the lens mount to set the shutter speed, but thisis not a bad position as there is precedent for this in Nikomat
and other cameras.
Exposure meterpressure from the sales department and went on sale first in the
US market the previous year, the M-1 was a revolutionarymodel that caused a stir in camera history by advocating asystem SLR from the start, and was the best of a group of
masterpieces created by Maitani Yoshihisa, including the Pen,the Pen F and later the OM-2 and the XA.
Air damper

Shuttermechanism

Figure 6-11 Internal Layout of the Olympus M-114)

Maitani also exercised ingenuity in making the shutter itself
more compact. The format is a horizontal-travel shutter, but
the ribbon that supported the front and rear curtains was
replaced with string. The string made it possible to lower theheight to the extent of the width of the ribbon. Finding adurable and temperature-insensitive string was difficult, but
Photograph 6-42 Olympus M-1

Maitani made arrangements for surgical suture thread.

(Provided by JCII Camera Museum)

Photograph 6-43 shows the string wrapped around the shutter
shaft. This string system was subsequently adopted by asuccession of other companies, and was also used in the Pentax
MX and the Contax RTS.

86

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchto have been a pioneer in the miniaturization of SLR cameras.
Although the ST-701 was ambitious in some respects, such as
the use of an SPD element for metering for the first time, it isunfortunate that other specifications such as the stop-down
metering of the M42 mount were somewhat outdated, causing
the camera to not be well received.
Photograph 6-43 Olympus Shutter Structure

6.4.2

To reduce the overall height, the condenser lens wasomitted. The condenser lens is used to make the image on thescreen uniformly bright all the way to the periphery, which isessential for high-end SLRs, but instead Maitani made thebottom of the pentaprism convex. However, there is aprecedent for this idea: Zunow also made the bottom of thepentaprism convex in order to reduce size.
The condenser lens is made of glass and is relatively large
in mass, so its omission also resulted in weight reduction. On
the other hand, Maitani avoided miniaturizing the pentaprism,
which would have had an immediate effect on weight
reduction. The priority was to ensure a certain degree of frame
coverage. With the same philosophy, the operation dials andother controls were never miniaturized, even though the aim
was to make the overall size smaller. The development policyof Maitani, who enjoyed photography, is evident. The designteam was instructed to thoroughly permeate the attitude ofpriority to miniaturization and weight reduction, and prioritize
the miniaturization of each individual component while
maintaining necessary functions.

Pentax Persistence

Until then, it was Asahi Optical's Pentax series that had beensmall and light in the SLR market. The appearance of the OM1 (M-1) seems like a bolt out of the blue, but the company atthe time was in the midst of a major conversion from the M42
mount to the K mount and, with the time being one of pure
pandemonium, had little choice but to just get it over with. In
1975, the company successfully switched to the K mount andreleased three models simultaneously, the K2, the KX and theKM, and from there turned its attention to the pursuit ofminiaturization.
The Pentax development team must have worked
desperately to develop a competing model, launching the MX
the year after the release of the K series to take the title of theworld's smallest and lightest Leica-format SLR. From the startof development to release of the product spanned only one anda half years; a heroic effort was made, indeed. This model is
0.5 mm smaller than the OM-1 in width, height and depth,
showing blatant persistence, but there is no doubt that it was
based on the OM-1, including the string structure of the shutter
curtain support and the convex on the bottom of the pentaprism.

I joined Nippon Kogaku and became involved in camera
design at the end of the 1970s, and remember a seniorcolleague jokingly express his surprise when he disassembled
the OM-1 and saw how small its parts were. “I wondered if the
Olympus designers mixed up the 5x drawings and 10x
drawings.”
To touch on the last of the “three evils,” shock, the OM-1
incorporates an air damper that acts when the mirror is driven.
There is a limit to reducing the moment of inertia and initial
speed of the mirror, and so to reduce the shock, an air damper

Photograph 6-44 Pentax MX

was installed to avoid a sudden increase in speed, like a door

(Provided by JCII Camera Museum)closer. This is another technology that was later taken up byother companies.
Olympus succeeded in reducing the volume and weight ofcarried equipment by 30% to 40% for a typical photo
expedition by reducing the size and weight of not only thecamera but also the interchangeable lens group. This was
widely well received by the general public, and the OM-1
became a huge hit, greatly redirecting the trend of SLR
development toward smaller and lighter cameras.
Just to add a note, Fuji Photo Film's Fujica ST-701, released
in 1970, was 8 mm taller than the OM-1 in terms of overall

A month later, the ME was released. This was even smaller
than the MX and also had automatic exposure. Since Olympus
had already introduced an AE model, the OM-2, to the market
a year earlier, it is thought that the company intended to line
up both a small manual model and an AE model at once.
Although the MX and the ME look similar in appearance
and size and seem to be siblings, they are not. The MX uses ahorizontal-travel shutter while the ME uses the Seiko MFC-E
jointly developed with Seikosha. The Seiko MFC-E is arevolutionary small shutter described in the shutter section.

height, but 3 mm shorter in width at 133 mm, and could be said
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –87

The winders are also not common. Perhaps, although not

first dual-priority AE SLR camera, and was also considerably

efficient, a separate development team was hurriedly

smaller than previous models, with a width of only 136 mm,
the same as the OM-1. This is one aspect of Minolta's productorganized to launch the ME to compete with the OM-2 incontrast to the mainstream MX.

strategy of not only downsizing but also incorporating the mostadvanced specifications at the time. The XG-E, released at the

6.4.3

same time as the XD, was also downsized to approximately thesame size, and was popular in the popular camera price range

Pursuit of Miniaturization by Each Company

Stimulated by the OM-1, other manufacturers accelerated
their move toward miniaturization. Nippon Kogaku developed
the Nikomat line in the popular price range in the direction ofdownsizing, and introduced the Nikon FM in 1977. It was amarket. Note that the XG-E was the first model to be equippedwith a unitized horizontal-travel shutter.

manual camera with a Copal unit shutter and, although it did
not have any major features in terms of specifications and wasstill one size larger than the OM series despite being small, wasfavorably received because of its quality and sturdiness,
typical of Nikon. In 1978, Nippon Kogaku introduced the FE,
an AE camera of about the same size and design as the FM.
This camera was also well received because of its ease of use,matching the catchphrase “Simple Nikon.”Photograph 6-47 Minolta XG-E
(Provided by JCII Camera Museum)

Minolta's SLRs in this family had numerous variations andmany popular models. Among them, the X-700 wasparticularly popular as a highly complete model with amatching small size, light weight and high functionality, andremained on the market for nearly 20 years after its launch in
1981. In terms of buzz, the X-7, which featured in its
Photograph 6-45 Nikon FM(Provided by JCII Camera Museum)

The FM and FE lines continued through the FM2, the FE2
and the like with almost the same appearance until the FM3A
released in 2001, but production was unavoidably terminated
due to difficulties in complying with the European RoHS
(Restriction of Hazardous Substances) Directive that came into
effect in 2006. If it had not been for that, the series would havecontinued quietly and become a long hit series.

Photograph 6-46 Nikon FM3A
(Provided by JCII Camera Museum)

Minolta's situation was a little different. Rather thanfocusing on miniaturization up front, the company chose tofocus on new functions and make miniaturization asubordinate strategy. The aforementioned Minolta XD was the88

commercials Miyazaki Yoshiko, a university student at thetime who later became a renowned actress, drew muchattention.
6.4.4
Miniaturization and Computerization
Canon's goal during this period was to reduce the size of thecamera while at the same time increasing its electronic
capabilities and productivity, and the AE-1, released in 1976,
was the fruition of these efforts. The AE-1 has appeared herein
at various times, but with the camera being so innovative, I
hope you forgive me.
The AE-1 was intended to be fully electronic and unitized.
Computerization, in particular, is closely related tominiaturization and weight reduction. For example, inconventional mechanical SLRs up until this time, the need fora series of operations such as shutter release, mirror drive,
aperture drive and shutter drive to be linked mechanicallyrequired means to transmit the operation of each mechanicalpart. This reduces the degree of freedom of design and can leadto wasted space, and also requires levers and gears fortransmission. On the other hand, if these are electricallytransmitted signals, they can be designed substantially as
independent units, eliminating the need for mechanicalinterlocking systems. In terms of the number of parts, the AE1 reportedly achieved a reduction of about 300 parts due tocomputerization. As information transmission between units
requires only the routing of lead wires, which were also

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

Conn

Subsubstratereplaced by flexible printed circuit boards (FPCs), the freedomof electronic component placement was also revolutionarily
improved. Simply put, electronic components could now belaid out as appropriate in the available space. Furthermore,
electronic components also became smaller with theintroduction of ICs and even higher density LSIs.
As mentioned above, the AE-1 became a big hit thanks to
its low price and a marketing strategy that put the winder at theforefront, but it had no small influence on the subsequent trendof SLR cameras, not only by downsizing through advanced
computerization and unitization, but also by reviewing the
production line in order to improve productivity.

6.5 Sophisticated Electrical Mounting with
Electronization
The Apple II was released in 1977 followed by the NEC
PC-8001 in 1979 as almost complete personal computers, andthe world was entering the “home computer” boom. As if instep with this trend, SLR cameras also entered an era in which
the mounting of CPUs (microprocessors) was the norm.
These microprocessors evolved from 4 bits to 8 bits,
reduced in package size and became less expensive, making it
possible to install a plurality in cameras as well, depending on
the model, to perform advanced calculations at high speed,which then became the demand. This is due to the need forhigh-speed and complex data processing with the inclusion ofAF, the evolution of multi-pattern metering, complex
sequence control and the like.
Initially, electronic components were placed by using larger
FPCs and efficiently routing them in the open spaces between
mechanical components in the camera, but eventually it
became necessary to install rigid boards with multiple layers
and higher density electronic components at key locations. For
this purpose, the internal layout of the camera had to proceedfrom the beginning under the assumption of the presence of anelectronic circuit board. However, mechanical parts also
became unitized and could be placed independently, andminiaturization of motors, actuators, sensors and batteries
advanced, resulting in the advantage of being able to reduce
the size of each unit itself. Project leaders and electrical andmechanical leaders began to reach a consensus on the layout
in the preliminary stages of model development. I remember
that, when I participated in the planning of the Nikon F5 as amechanical designer, the person in charge of electronics
brought over a large multilayer circuit board fromdisassembled parts of a Sony Handycam TR-55 (a “passportsize” hit) and demanded an equivalent amount of mounting
space in the F5. After painstaking efforts to squeeze out such
space, we were finally able to secure a location where the main
substrate could be situated.

Unit shutter

Connectors

Subsubstrate

Main substrate
Rewinding motor

Charge motor

Photograph 6-48 Internal Mounting of the Nikon F515)

The era was now one in which project leaders had to haveknowledge not only of mechanical parts but also of electricalcircuits and mounting.

6.6

Evolution of the Viewfinder

Needless to say, the most significant difference between an
SLR and a rangefinder camera is the viewfinder. This section
describes the technological evolution of the SLR viewfinder.
To review terminology, Figure 6-12 illustrates a typical SLR
viewfinder configuration. The main components are the screen,condenser lens, pentaprism and eyepiece.
In SLRs, the screen for checking the captured image inadvance is placed at a position equivalent to the film surface.
To obtain an image as close as possible to the captured image,including blurring, a transparent plastic having a matte finish
on one side is used.
The condenser lens prevents the periphery of the image on
the screen from becoming dark and is a convex lens, but aFresnel lens is substituted or used along with the convex lensin some models.
In the pentaprism, an image reflected three times (two times
by prism surfaces due to the 90-degree roof shape) is guided
to the eyepiece. The eyepiece group can be thought of as amagnifying loupe focused on the screen.
Pentaprism
Eyepiece

Condenser lensViewfinder screen

Mirror

Shooting lensFigure 6-12 Optical Path Diagram of SLR

6.6.1

ScreenThe screen is used not only to check the composition of theimage, but also to check the focus of the captured image, checkthe blurriness and diffuse light to the metering system.
Adequate brightness and diffusion are also contradictoryelements, requiring each company’s utmost attention. Early
SLRs were molded in dies matted by a sand finish or a blasting

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –89

process. At the time, the screen for the Nikon F was highlyinterchangeable screens often offer several different screen

regarded and was said to be the benchmark for many

types so that the user can select the one with the best angle forcompanies.

the lens used.

However, with the sand finish, a feeling of graininessremains and the image tends to look dark, so brightening(Electron microscope image at
2000x)

attempts were made. In the Leicaflex, all areas except thecenter were made transparent so that an aerial image could beviewed as is. Leica, the leader in rangefinder cameras, may
have wanted to present an image as clear as that of arangefinder, but this camera was not well received due to theConventional matte surface (sand finish mattesurface)disadvantage of not allowing the user to fully check for
blurriness.
As a screen that is bright and allows the user to check for
blurriness, the Acute Matte of the Minolta XD is a pioneer.
The XD was the first camera with dual-priority AE and

Laser Matte surface

excelled in miniaturization as previously mentioned, but also
did not neglect screen ingenuity. The Acute Matte is composedof cones having a diameter of about 20 µm in regular intervals,
as shown in the upper right of Photograph 6-49. Although aviewfinder that is bright and allows the user to easily focus andcheck for blurriness was realized, the viewfinder had thedrawback that the regularity of the unevenness interfered withpatterns, such as a striped pattern, of the subject, causing moiré
fringes.

Bright Laser Matte surface

Photograph 6-50

Matte Surfaces of Canon17)

Based on the same principle as the split prism, there are also
some matte surfaces with numerous fine pyramid-shaped
microprisms aligned side by side. The image appears glary

Brightness of viewfinderwhen out of focus and clear at the focal point, making focusing
easier. The Acute Matte mentioned above is, if anything, an
Microprism

extremely fine version of a microprism. Figure 6-13 illustrates

Acute Mattean example of a screen that has a split prism in the center andConventional mattemicroprisms around it.

Split prism
Matte surface
Fnumber of lensPhotograph 6-49

Minolta Acute Matte16)

To solve this problem, a technology was developed to create“randomly smooth unevenness” in dies by mobilizing

Microprisms

Figure 6-13 Microprisms and Split Prism

photoresist and other chemical effects, and this technology was

To prevent shading in the split area, techniques of providing

put to practical use in the Laser Matte and the Bright Lasera split prism surface with fine irregularities or surfaces at

Matte of Canon. Other companies followed suit, and Nikon,

different angles were developed. These prisms are called thefor example, developed the Clear Matte.

Canon New Split and the Nikon Dual Split.

Although focusing is possible with a matte surface, for moreaccurate and faster focusing, some cameras use a split-image
system with two wedge-shaped prisms placed in the center ofthe screen, aiming for an effect similar to the dual-imagealignment of the rangefinder camera. In an out-of-focus state,

Enlarged view of New Split prism

the images of the two prisms are positioned in directions

Partial 3D view of New Split prism

opposite to each other, making it possible to determine thestate of focus with greater precision. A large wedge angle

Figure 6-14 New Split Prism18)

improves accuracy, but shade occurs with a lens having a large
aperture value (slow lens). For this reason, cameras with

90

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchThere were many variations of the split area since the early
SLRs. For example, the Canonflex released in 1959 adopted a

Movable mirror

technology called echelette grating, and one may say that theabove New Split, introduced about 40 years later, is a
developed form of this technology, echoing the spirit ofdiscovering new things by studying the past, and is a reminderof the bygone era when engineers pooled their wisdom
together in an effort to make the SLR viewfinders competitive
with the double-image alignment of the rangefinder camera.

Figure 6-16
Optical Path Diagram of
Ricohflex TLS 401

Ricoh had succeeded in adopting a plastic mirror for theroof prism surface with the 126C Flex, an SLR that, although
not designed for 35 mm film, uses Instamatic (126 type film),
and reutilized this technology. Thus, the first 35 mm SLR witha viewfinder that could be switched to eye level or waist levelby moving the movable mirror up and down due to theadvantages of its hollow design, as shown in Figure 6-16, wascompleted. Although this model was ambitious, including
features such as the mirror meter used in the Topcon RE Super
as a metering system, it was not a sales success and no
successor was ever produced, perhaps because of the old-

Figure 6-15 Echelette Grating

19)

Cameras with interchangeable screens combine thesetechnologies with further innovations to offer a large lineup of
appropriate screens for a variety of applications, with somemodels offering more than 30 variations.
6.6.2

fashioned M42 mount and the camera size.
It should be noted that, as 35 mm SLRs that could beswitched to eye level or waist level, the Rolleiflex SL2000F
and its successors, which were released by Franke & Heideckeof West Germany in 1981, are extremely unique camera and,as one form of the 35 mm SLR camera, the Rolleiflex

Pentamirror Debut and Special Viewfinder

The basic structure of the pentaprism, which is the symbol

SL2000F is shown in Photograph 6-51.

of SLRs, has not changed since the original Contax S, although
there have been partial modifications due to improvements inglass materials and additions of display and metering systems.
The outstanding idea of using the roof prism surfaces to return
an image left-right reversed on the screen to the correct image
led to the breakthrough of the SLR, and the same opticalprinciple is still used in today's digital SLRs.
One of the most significant technological advances in the
pentaprism portion of the camera is the debut of the pentamirror. Pentaprisms are almost ideal for SLR viewfinder optics,
but are heavy and result in poor productivity due to the massof glass. If the optical path of the pentaprism could be made ofmirrors, the conventional glass portion would be hollow anddrastic weight reduction could be achieved, but ensuring theflatness and accuracy of the roof portion was difficult. Early
35 mm SLRs, such as the Ricohflex TLS 401, achieved this.

Photograph 6-51 Rolleiflex SL2000F(Provided by JCII Camera Museum)With recent advances in molding and die machining
technologies, the pentamirror system has gradually been
adopted, and today the majority of SLRs in the popular pricerange use this system. Although the lightweight and low cost
are attractive, the flatness of each surface is somewhat inferior
to that of glass reflective surfaces, making pentaprisms stillprevalent in high-end models.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –91

6.6.3Specifications of Viewfinder System
The eyepiece group, together with the pentaprism (orpentamirror), is used to magnify the image on the screen forobservation and directly affects the visibility of the viewfinder,
making the specifications of frame coverage, magnification,
eyepoint and diopter important.
The frame coverage is the ratio of the shooting frame to theedge of the viewfinder frame (not the area ratio). Naturally,
100% is the demand, but various restrictions make that
achievement surprisingly difficult. Even for high-end SLRs for
professional use, the Canon F-1 and Contax RTS come ininsufficient at about 97% and 92%, respectively, but the Nikon
F achieved about 100% from the beginning because Fuketa,
the design leader, made it a top priority. This specification has
been carried over from the F2, the successor to the F, to the F6,
and other companies have also achieved approximately 100%
frame coverage in the field of professional high-end models.
There is a trade-off between viewfinder magnification andeyepoint. Eyepoint is the distance from the eyepiece to thefurthest eye position from which the frame can be viewed
without vignetting. Increasing the magnification makes theimage itself easier to see, but the eyepoint becomes shorter,
resulting in vignetting in the periphery of the frame, especiallyfor people wearing glasses. An optical design that provides along eyepoint while maintaining magnification is required, andthe optimum choice is made according to the positioning andconcept of the model.
The diopter depends on the distance to the imaginary image
magnified by the eyepiece and is usually measured in diopters(Dp or D), the reciprocal of distance (m). If the position of theimaginary image is 1 m in front of the eye, the diopter is -1 Dp.
With normal eyesight, viewing is easy at this distance.
However, in consideration of people with nearsightedness orfarsightedness, cameras that can be fitted with a diopteradjustable lens in the eyepiece or that allow diopter adjustment
by moving a part of the eyepiece group are now commonly
available. As an example of diopter adjustment, the diopter
adjustment knob of the Nikon F4 is shown in Photograph 6-52.

Photograph 6-52

Diopter Adjustment Knob of the
Nikon F4

6.6.4
Development of Viewfinder Internal Display
When checking the composition of an image in the
viewfinder, it is better to be able to simultaneously checkshooting-related information as well. Therefore, the display inthe viewfinder was gradually enhanced. In the early days ofthe built-in metering system, the needle of the meter indicating92

the measured light value was shown in the viewfinder frame
as is, and a desired exposure value could be obtained byaligning the needle to a fixed point by changing the aperture or
shutter speed while looking at the needle. Subsequently, it was
better to be able to see the aperture value and the shutter speed
value, and so some cameras were developed with an ingenious
optical system that guides an optical path through thepentaprism, allowing the lens aperture value display and the
shutter speed value to be seen directly or indirectly. In the caseof a manual exposure setting, the display need only show theset value, but in the case of automatic exposure, the display
must show the control value, not the set value. In this case, aconfiguration was adopted in which a display panel listing the
shutter speed values was arranged, and the control value wasindicated by a meter needle or dot LED. An example isillustrated in Figure 6-17.

Figure 6-17 Display in Viewfinder of the Nikon FE20)

Later, with the spread of digital watches and calculators,
seven-segment digital displays became widely accepted, andthere was a movement to adopt such displays in cameras aswell. The first camera to use seven-segment LEDs for the
display in the viewfinder was the Fujica ST901 in 1974.
This camera could digitally display shutter speeds from1/1000 to 20 seconds, but had many limitations and could notdisplay 1/250 or 1/2000. With the ST801, a lower-end model,
being capable of high shutter speeds of up to 1/2000, theST901 specifications being limited to 1/1000 is a serious
display limitation.
For reasons such as power saving, liquid crystal displays(LCDs) were introduced in camera viewfinders just as LCDs
were introduced in calculators. Figure 6-18 shows an exampleof the LCD of the Nikon F3 released in 1980. The upper left
side of the frame is the LCD, and the center is a direct-reading
display for optically viewing the aperture value characters of
the lens. Since calculators and watches with LCD had theirmarket debut in 1973 and the technology was still new, there
were concerns that the displays would become difficult to readover time, so the early F3 catalogs included a sentence statingthat parts would be replaced free of charge in the event of aging.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchFigure 6-18 Display in Viewfinder of the Nikon F321)

The LCD was subsequently widely adopted because of its
high degree of freedom in display design and content. In
addition to the aperture value, shutter release time and the like,the LCD can display the number of shots, a bar display in placeof a meter, and the like, all at once. Although the liquid crystal
is not a light-emitting device, with the mounting of a backlight,
there are no hindrances to nighttime photography or the like.
In recent years, some models have emerged with light-emitting
displays such as organic electroluminescence.

Photograph 6-53 Ricoh XR-S + AF Rikenon 50/F2(Provided by JCII Camera Museum)Any camera could have earned the title of the world’s firstcommercially available 35 mm AF SLR system as long as
equipped with a motor in the lens, a battery and an AF sensor,
and this one can be said to meet the criteria, but the camera

6.7 Autofocus

struck out swinging due to its ruggedness and its principle
drawback of poor AF accuracy at long distances. Another AF

With the development of auto-exposure and auto-feedinglens of this type that used an optical path other than thetechnologies, the big remaining automation technology wasshooting lens was the Canon New FD35-70/F4 AF lens

autofocus (AF). The principles of AF have been studied for areleased in May 1981.

long time, and mainly include the rangefinder method, thecontrast method and the phase difference detection method.
These methods are described below, with specific products

6.7.2

The TTL AF method used in SLRs

The rangefinder method used in SLRs did not fit the SLR
principle of viewing the image from the shooting lens as is,introduced.

and a TTL AF method was still desired. TTL AF methods can
6.7.1

AF Lenses for SLRs Using Rangefinder
Methodbe broadly classified into two categories: a contrast detection

The rangefinder method, as the name suggests, is based on
the principle of triangulation used in rangefinder cameras todate, and electrically performs the dual image alignment of amethod and a phase difference detection method. Thesemethods are described below.
Figure 6-19 illustrates the contrast detection method.

traditional rangefinder. In this method, the pair of images fromtwo windows spaced apart are detected by a line sensor, andone optical path need only be swung in conjunction with
distance adjustment of the lens. Once the relationship between
the focal point position and the two images is determined, thefocus state can be detected.
Although not an SLR, the first commercially available
camera with AF was the Konica C35AF, which used thisrangefinder method. The AF sensor was the American

Sensor B

Figure 6-19

Sensor A

Principle of Contrast AF Method

Honeywell Visitronic. This method is not suitable for SLRs
because the optics for AF are separate from the shooting lens,A line sensor or image sensor is placed at a position

but Ricoh's AF Rikenon 50/F2 lens, released in February 1981

equivalent to the film surface, and the contrast of the image is

as an interchangeable lens for SLRs, uses this method.

determined from the difference in output of each pixel, withthe highest position being judged as in focus. As long as thesensor is installed correctly, the design has the advantage ofhigh accuracy and simple structure. However, there are
drawbacks, such as the fact that, in principle, whether in front
or in back of the focal point position cannot be determined
unless the lens is moved to change the contrast, andovershooting is required to find the highest point of contrast.
Normally, the two sensors A and B are placed as shown in the
Systematic Survey on 35 mm High End Camera – History from Leica to SLR –93

figure to determine the front and back of the focal pointthat can display front focus, rear focus and in-focus. Based on

position based on the difference in output, but this is difficult

the Pentax ME Super, the camera was the first AF SLR withto do when the image is extensively blurred, and sometimes

only an additional AF-related configuration and only one AF

the amount of light from each sensor is cut in half, resulting indedicated lens, but was not well received due to its poor AF

limited effectiveness.

performance, which is the most important factor.

The phase difference detection method, in principle, is to
identify the position of the primary image, that is, the focus
position, by re-imaging the primary image of the shooting lenswith a set of relay lenses placed at different rearward positions
and checking the status of the re-imaging. Figure 6-20
illustrates the phase difference detection method.
Shooting lensPhotograph 6-54 Pentax ME-F
Focal plane
Aperture plate
Relay lensLine sensor
OutputRear focus

In focus

Front focus

Figure 6-20 Principle of Phase Difference Detection AF
MethodSets of relay lenses and line sensors placed at the rear of thecamera are each used to observe the primary image formed by
the shooting lens. In the case of the front focus and in the caseof the rear focus, the secondary image position shifts indifferent directions relative to the secondary image output state(Provided by JCII Camera Museum)The early 1980s was a time when companies were trying tofigure out how to tackle AF. Existing lenses on the market
could not be ignored, and resetting everything andtransitioning to a new system meant high risk, making
companies hesitant. There was also the question of whether toadopt the relatively simple contrast AF technology or to use
the TCL module from Honeywell, which had been marketed
as an AF sensor for phase difference detection. It was a time
when experimental models were introduced to the market as
each company approached the frontier of AF with trepidation.
First,

manufacturers

who

adoptedonly

focus-aidof each sensor when in focus, and thus the amount of shift
indicates the amount of focus deviation, and the shift direction

specifications, which also benefit conventional lenses,

indicates the deviation direction. In other words, in contrast to
the contrast detection method of conventional SLRs that isused the contrast AF method, enabling focus-aids (called

appeared. In March 1982, Canon introduced the AL-1 that
Quick Focus by Canon) with conventional lenses.

based on focusing an image on a matte surface, this methodaligns two images that are split prism. Although this method
requires more space because the relay lens and sensor must be
installed rearward of the primary image with a certain optical
path length maintained, the deviation amount and deviation
direction are easily understood, which is a major advantage
over the contrast detection method, making this method themainstream with the exception of the early days of AF SLRs.
6.7.3

Transitional AF SLRs

The first commercially available AF SLR with an AF sensor
in the camera interior was the Asahi Optical Pentax ME-F
released in November 1981. This camera has a contrast AF
sensor on the camera side, and sends a drive signal to thededicated lens based on the distance measured. The lens side
has a lens drive motor and battery, and the system drives thelens by signals from the camera side. With the AF sensor on
the camera side, when a conventional lens is attached, thecamera has a so-called focus-aid function in the viewfinder

94

Photograph 6-55 Canon AL-1
(Provided by Canon Camera Museum)

Olympus and Minolta also followed the same trend, with
Olympus launching the OM30 in November 1982 and Minolta
launching the X-600 in April 1983, both with focus-aid
specifications. Olympus, like Pentax, provided one AFdedicated lens with the motor and battery on the lens side.
These two models were equipped with the Honeywell TCL
module, which used the phase difference detection method, in
the AF sensor, instead of a contrast AF system.

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchIn Nikon's case, the company entered the AF SLR market
with a different approach than its competitors. The F3AF,
released in April 1983, took advantage of the fact that the F3,
a high-end professional-use model, had an interchangeable
viewfinder, and kept the modifications to the minimum
necessary, just adding contacts to the camera. The company
enabled focus-aids by replacing the viewfinder with an AF
viewfinder, and prepared two dedicated AF lenses and an AF
teleconverter for attachment to the rear end of a conventionallens, enabling AF for older lenses by its attachment. The
dedicated lenses have only a built-in motor and no battery, so

Photograph 6-56 Minolta α-7000

are not much larger than an ordinary lens. On the other hand,the viewfinder has a built-in battery, AF sensor and optics, so
it is huge. Claimed for professional applications and used with
Nikon's own AF sensor instead of the TCL module, the camera
boasted an AF performance and drive speed that were a step
above those of other companies, but was naturally expensive
and large, and did not become widely used like other AF SLRsof the period.

(Provided by JCII Camera Museum)The α-7000, released in February 1985, incorporated an AF
sensor, battery and lens drive motor on the camera side, andwas configured to freely allow distance adjustment on the lensside using an AF coupling, similar to the tip of a flatheadscrewdriver, provided in the lens mount area. In this way, there
is no need to place a drive motor inside the lens, making it
possible to retain the size the same as a conventional lens. The
AF sensor itself was made by Toshiba, and the optics related
to AF were designed in-house, which would later become aproblem, but the AF performance was outstanding comparedto the TCL module used in the X-600.
The information necessary for focus and exposureadjustment specific to the new lens is held as ROM on the lensside, and this information is communicated to the camera side,achieving optimal control for any lens. This made it possible
to achieve a faster AF drive, the long-cherished wish for AF
SLRs. The camera was a big hit, not so much for its good
performance as a camera and the fact that most of its functions,such as winding and rewinding, were automated, but because

Figure 6-21

6.7.4

Perspective View of the Nikon F3AF22)

it maintained a price comparable to that of the conventional
mid-range model. With this camera, Minolta, which had been
third or fourth in the SLR market share, quickly rose toward

Debut of the Minolta α-7000

the top.

The first half of the 1980s was a period of trial and error forNormally, a change of lens mount is a big risk for a

the major SLR manufacturers with regard to AF compatibility,

manufacturer, but in Minolta's case, the trade-off was a greatas described in the previous section. All manufacturers were

improvement in camera performance and, with careful

studying ways to solve the problem, but they were struggling

preparation of interchangeable lenses and accessories, theto deal not only with the difficulty of the AF function itself,

camera was rather well received by the market. It was also

but also with the systemic nature unique to SLR cameras. The

significant that the company had developed its lineup by

fact that so many interchangeable lenses were introduced tolaunching the high-end α-9000 six months after the α-7000,

the market held manufacturers back and prevented them fromfollowed by the popular model, theα-5000, the following year.

taking the next step.
It was Minolta that boldly abandoned most of its
conventional systems and tried to break through with a new
system. With Minolta being one of the few manufacturers thatprided itself on not having changed its basic lens mount since

Three years after the release of the α-7000, the α-7700i, its
normal evolution version, was released and well received,
leaving other manufacturers laps behind. Minolta seemed to besailing smoothly, but at this time already had one foot mired ina muddy patent dispute with Honeywell.

it introduced its first SLR in 1957, the public was surprised,
but also awed by the excellence of the new system.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –95

6.7.5

Patent Dispute

Honeywell's cleverness also lies in its choice of a jury trial

Honeywell's TCL module, which was adopted in the SLRs

(the plaintiff has a choice). In hindsight, since the jury, madeof a number of manufacturers, utilizes the phase difference

up of average persons not familiar with the technology, was todetection principle, but to reduce size, the optics and AF

decide whether “an engineer of ordinary skill would easily

elements are actually contained in a single package. Although

recognize such an omission,” the inevitable victorious

the module has the advantage of being space-efficient, making

outcome was as clear as day.

it easy to mount inside a camera, its AF performance was

The case, which took five years to fight, ended in Minolta's

somewhat unsatisfactory. For this reason, Minolta, which once

defeat. The company paid approximately 16.5 billion yen in

adopted the TCL in the X-600, switched to an AF systemcompensation to settle the case. Other camera manufacturers,

developed in-house when the company staked everything on

who had been watching warily, lost their will to fight,

the α system.

concluding they would not win due to Honeywell’s homefield

After witnessing the success of the α-7000, other companies
began to develop their own AF sensors, resulting in a sharp
decline in sales of the TCL module. Honeywell, however, wasready for its next move. The company sued Minolta in April
1987, claiming that it was in violation of its US patents. The
patents in question were several, but the most important is USP
3,875,401, commonly known as Patent 401 or the Stauffer
Patent after its inventor.
Normally, there are two main strategies to take when beingsued for infringement of a patent: proving non-infringement oradvantage, and all agreed to the settlement, paying large sumsof money23).
If we look at this case as part of a larger trend of the times,
it seems that it was not unrelated to the fact that a pro-patent
shift (strengthening patent protection) was gaining momentum
in the US as the US manufacturing industry, led by theautomobile industry, fell into a downturn and, personally, I
feel some sympathy for the Minolta side.
6.7.6

Evolution of AF Technology

proving invalidity of the patent in question. Minolta took the

Did the defeat in the nightmarish Honeywell AF lawsuit

latter. This is because there were actually publicly known

leave Japanese camera manufacturers exhausted? No, at least

examples that seemed influential.

not on the surface. The development race came to a standstill

Even in the SLR era, Leitz worked diligently to improve its

for a moment, but there was no manufacturer other than those

rangefinder models. These efforts also extended to autofocus

in Japan that could take advantage of the situation and catchtechnology, and prior to Patent 401, the company had applied

up. After paying a hefty settlement as pro-patent tuition, so tofor an important AF-related patent, USP 3,860,935 (hereafter,

speak, the manufacturers returned to developing SLRs as if

Patent 935). It was the invention of Dr. Ludwig Leitz, thenothing had happened.

second son of Ernst Leitz II who once made the wise decision
to introduce Leica to the world. Minolta argued that Patent 401

Below, the technological evolution of AF while bediscussed while following the trends of each company.

was invalid because of a known example, Patent 935. The factthat the Japanese application for Honeywell's invention was
not published is evidence of this assertion.

(1) AF response by each company
In April 1985, two months after the release of the α-7000,

However, Honeywell, which is well versed in patent

Canon launched the T80, an AF SLR, but the camera failed todisputes in the US and has been through many ordeals, noted

perform well due its pre-α shock specifications, including athat some lenses were not depicted in the illustrations of Patentcontrast AF and only one AF lens. The amazing thing about

935, and argued that it was incomplete as an AF device andCanon is that the company just knew that, in order to catch up

therefore did not constitute a known example.

with the α, they needed to rethink their system from theIt has been my experience that, in patent specifications andbeginning, just like Minolta. After enduring several years of

explanatory drawings, especially in the case of principle-based

development, in 1987 the company converted to a completely

inventions, detailed parts that are obvious to an engineer may

new system, including the lens mount, and introduced the EOS

be omitted. Dr. Leitz, who wrote Patent 935, probably intended

620 and 650 as its first new SLRs.

to omit them.
Even if some lenses are omitted, the validity of theinvention is not impaired if the omission is easily recognized
by a person of ordinary skill in the art, and therefore the issue
is whether a person of ordinary skill in the art would recognize
the omission of such lenses.

96

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 MarchPhotograph 6-57 EOS 650(Provided by Canon Camera Museum)The large mount, which has no vignetting even with large
diameter lenses, has no mechanical linkage at all, and all
signals are exchanged electrically. This was achieved byproviding each lens with its own AF drive motor, but also on
the strength of having Canon Precision as a motor
manufacturer under the Canon umbrella and the ability to use
ultrasonic motors, which are suitable for driving lenses, as oneof the technologies in its possession.
Starting with the EOS 620 and 650, the company
consistently expanded its lineup from mid- and high-end
models to popular models from the following year, 1988,
regaining the top position in the SLR market. Among them, theEOS Kiss series was a huge sales success, opening up newmarkets as SLR cameras for women and families.
At the top of the lineup, as a professional AF SLR camera,
the EOS-1 was released in 1989 and evolved in function while
continuing in spirit in the EOS-1N in 1994 and the EOS-1V in
2000, becoming the flagship series of Canon SLRs.
Like Minolta, this is an example of a company thatsucceeded in drastically revamping its lens mounts to support
AF. Needless to say, this was made possible not only by a full
lineup of cameras, but also by well-planned preparation ofinterchangeable lenses and accessories as well as the technicalbackup to support these lenses and accessories.
In the same year as the α-7000 shock, Nippon Kogaku
launched the F-301 with a built-in motor, as mentioned above.
Although the F-301 was not an AF model, the F-501, an AF
model based on this, was released in April 1986, and thissystem was ready to follow on the back of the α. With the lensPhotograph 6-58 Nikon F-501(Provided by JCII Camera Museum)

Subsequently as well, Nikon constantly released othermodels, such as the F-401, released in June 1987, as an AF
SLR with a standard SLR design with a built-in flash andNikon's proprietary AM200 AF sensor, and the F-801, whichboasted a shutter speed of 1/8000 as well as other high basic
performance standards.
The first AF camera for professional use, the F4, wasreleased in 1988, but many pointed out that its AF performance
was insufficient for professional equipment, so the F5,
released in 1996, boasted a five-point AF area and arevolutionarily fast AF drive speed. Furthermore, what is
unique to Nikon's strategy is that Nikon provided two different
types of lens drives, one from the camera side and the otherbased on an in-lens motor, differentiating use according to lens
type. For super-telephoto and other lenses with heavy driven
optics, a dedicated motor was provided in the lens, whilesmaller lenses with less energy to be driven were coupling
driven from the camera side. Although there is a disadvantage
of wasting the drive mechanism on the camera side when using
a lens with a drive motor, there is an advantage of being able
to use a drive system appropriate to the lens type, so hasadvantages and disadvantages. This can also be said to beanother measure to continue the traditional Nikon F mount.
Olympus launched its first AF SLR, the OM707, in October
1986. As a phase difference detection AF SLR, the camera
took third, following Minolta and Nikon.

drive adopting an AF coupling method that utilizes a motor on
the camera side, similar to the α method, and the AF sensor
using Honeywell's TCL, the model was somewhat lacking fora latecomer, but Nikon's claim to fame was that it did notchange the lens mount. Without changing the F mount, which
had been in use since 1959, the company adopted measures
such as adding the AF coupling and new electrical contacts for
AF. Although the camera has a sense of building an extension
on top of an extension, it appears to have received a certain
level of recognition from long-time core Nikon fans.

Photograph 6-59 Olympus OM707(Provided by JCII Camera Museum)

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –97

The lens mount is similar to the Nikon counterpart, whichat Photokina, a photography, video and imaging fair, in 1982.

added an AF coupling and electrical contacts to the

Like Minolta, the camera uses AF couplings to drive the lensconventional OM mount. After all, there was no time to review

from the camera side. A patent was filed for this in-camera AF

from scratch and create a new AF lens mount design, and risk

drive motor, but Minolta was allowed to file first by a mere

was most likely to be avoided. In keeping with the Olympus

week or so24). Whether this was the reason or not is unclear,corporate culture of unique specifications different from those

but this prototype never made it to the market.

of its competitors, this camera also incorporates various

Kyocera's first AF SLR was the 230AF, released in

specifications, including a pop-up flash built into the grip, an

December 1986. Although the mount was not the

AF auxiliary light that provides illumination for distanceContax/Yashica mount that had been used since the Contax

measurementof

RTS debut and the Kyocera AF mount was newly adopted forinterchangeable lenses that are all controlled from the camera

AF, conventional lenses could still be used with someside, eliminating even the distance ring. However, it ended up

limitations with a 1.6x AF converter.

in

dark

conditions,

and

a

group

being a failure, as evidenced by the fact that no successor tothis camera was ever produced. There are some subjects thatare just not good for AF, and to manually focus on them, youhave to use a power focus switch on the camera because there
is no distance ring, but this operation is not very comfortable.
It seems that the fatal mistake was to cut corners in the basic
camera operation of focusing.
In March 1987, about two years after the α-7000, Asahi
Optical introduced the Pentax SFX, a phase difference
detection AF SLR camera.
Photograph 6-61 Kyocera 230 AF(Provided by JCII Camera Museum)This model incorporated innovative ideas, such as theability of use as an SLR with a built-in flash by combining a
dedicated flash with the pentaprism area, and successor models
were released, including a popular type, but these did not reachthe point of being on par with other companies in terms of sales.
Kyocera continued to offer two series of mounts, thisPhotograph 6-60

Pentax SFX(Provided by JCII Camera Museum)

Kyocera AF mount and the non-AF Contax/Yashica mount,but in 1996, Kyocera suddenly released the Contax AX.

The lens mount was, of course, similar to the Nikon
counterpart, which added an AF coupling and electricalcontacts to the conventional mount. While the earlier Nikon
and Olympus models were TCL module cameras, this camera
introduced Asahi Optical's own SAFOX AF system, including
an AF sensor and a control system. Other unique designs, suchas the LCD and flash above the pentaprism area, were also wellreceived, but perhaps because what was wanted for Pentax was
a compact and lightweight AF SLR rather than somethingunique, the company has since returned to a relatively
orthodox design in the Z series and MZ series, with a few
exceptions.
In 1985, when the α-7000 shock occurred, Yashica had
already merged with Kyocera, but the design and development
team of the former Yashica had the mettle to keep up with thecompetition. As mentioned above, even for an AF SLR, aprototype with AF built into the Contax 137 MD was exhibited98

Photograph 6-62 Contax AX(Provided by JCII Camera Museum)The surprising thing about this camera is that the lens is not
driven. Instead, an ultrasonic motor inside the camera moves
the film support back and forth on the camera side to perform
AF. It was the first ever AF SLR with automatic back-focusing,a unique feature that made AF possible even with conventional
lenses. On the other hand, the camera body had to be larger
and more expensive, and unfortunately, the model was not well

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchreceived in the market. From a camera engineer's point of view,
however, the efforts of the Kyocera camera design/development team in confronting and accomplishing thisadvanced technology should be highly commended.
Kyocera then made a complete change to its newly
developed, fully electronically controlled N-mount system in
2000. Although it was a major shift in the direction ofdigitalization, it was already too late, and the company decided
to withdraw from the camera business in 2005 without seeing
any sales success. The reason for this was cited as, “We
couldn't keep up with rapid changes in the market.”(2) Development of multiple AF points
Early AF SLRs could only measure distances at the centerof the shooting frame, which limited the composition of theimage. Attempts were made to create a multi-point
measurement system provided with AF points at the center aswell as other locations. Minolta, a step ahead in AF technology,
introduced four AF points with the α-7xi released in June 1991.
Another technique similar to multiple AF points is crosstype AF points. Phase difference detection AF in the earlystages only looked at the correlation between the images of
two line sensors placed horizontally across the frame, so in
principle it was not possible to measure distance with a subject
such as a horizontal line. Therefore, the line sensors are placed
vertically to see the correlation in the vertical direction of theframe as well. As an example of a multipoint and cross-typesystem, the AF optical path diagram of the Nikon F5 released
in 1996 is illustrated in Figure 6-22. In this model, three CCD
sensor units are placed at the bottom of the mirror box toenable distance measurement at a total of five points: center,
top, bottom, left and right. Three of these points, the center andleft and right, can be understood as a cross.

Mask
Condenser lensCCD sensor
unit

Mirror
Separator lensCCD sensor
unit

CCD sensor
unit

AF optical path
diagramFigure 6-22

Five-Point AF Optical Path Diagramof the Nikon F525)

The trend toward multiple AF points accelerated in othercompanies as well. For the 35 mm SLR camera, the EOS-3
released in November 1998 and the EOS-1V released in March
2000 boasted the highest number of AF points at 45 and, forthe latest digital SLR camera, some cameras even have morethan 100 AF points. These evolve with the technologicaldevelopment of CCD and CMOS sensors and the advancementof other AF-related technologies described below, and the field
is expected to continue to develop greatly in the future, with
the incorporation of AI technology, for example.

(3) AF on-screen display
As the number of AF points increased, it became necessary
to indicate which AF point was selected. Such information isusually displayed on the screen, and thus the display is referred
to as an on-screen display or superimposed display. There areseveral methods for achieving this, which are described below.
(1) LED illumination method
In this method, an LED light is illuminated to indicate theposition on the screen corresponding to the AF point. Various
optical paths are possible, but Figure 6-23 illustrates a generalexample. The light-emitting portion includes the same numberof LEDs as AF points. These LEDs can emit light
independently and emit light through individual light paths topredetermined positions on the screen. The screen has
diffusibility, and thus a portion of the light is reflected toward
the eyepiece lens, making the light visible to the photographer.
This method is a luminescent type, making the display visible
even in the dark, and the structure is relatively simple as longas a high-precision optical path system is provided. Although
this method has the disadvantage that the light cannot be
continuously left on from the standpoint of energy
conservation, it is the most commonly used.
Optical path diagram ofsuperimposed display
Lightemitting
portionViewfinder
screenMirrorFigure 6-23

Optical Path Diagram of LED-Type
Superimposed Display26)(2) Liquid crystal display (LCD)
A method that utilizes an LCD also exists, which was usedin the Minolta α-7700i. LCDs are commonly used in various
types of devices and have the advantage of being stable interms of quality and price. The format has a high degree of
freedom, allowing indicators of information other than AF
points, such as grid lines for checking the composition andlight metering areas, to be displayed on the screen. On theother hand, the LCD has the disadvantage that, when used witha viewfinder, which requires a transmissive type, the entire
viewfinder becomes dark due to the low transmittance of the
LCD transparent portion. Further, because LCDs are not lightemitting elements, they have the disadvantage of being
difficult to see with dark subjects.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –99

Some cameras adopt PN LCDs to compensate for theseshortcomings. PN is an abbreviation for polymer network. In
a PN, when a liquid crystal material is encapsulated in a
network made of UV curable resin or the like, the material iscloudy when not energized and aligned in the electrolytic
direction and transparent when energized. Because of thisproperty, this liquid crystal is also referred to as diffusion-type
liquid crystal. Unlike conventional LCDs, the diffusion-type
does not use a polarizing plate, resulting in high transmittance,
and the cloudy diffusion display portion glows when irradiatedby LED light, making it visible even with dark subjects
without the use of separate LEDs for each AF point.
The first camera with a PN LCD was the Nikon F80,
released in 2000. Figure 6-24 illustrates an exploded view ofthe viewfinder portion of this model. LEDs and light guides
are placed on the left and right sides of the PN LCD plate andemit light from both sides at low luminance.

(4) Evolution of AF function(1) Motion prediction
In sports photography and other fields where moving
subjects are photographed, the time lag of the shutter releasecan be a problem. Even if the shutter is released at the rightmoment, a time lag occurs in the SLR camera due to mirror
lock-up and the like, causing the image to be out of focus when
the distance to the subject changes during that period. To
prevent this, a motion prediction function was conceived thatmeasures the speed at which the subject is moving and predicts
the distance the subject will travel during the release time lag,ensuring that the image will not be out of focus at the time ofshooting.
The Minolta α-7700i, released in 1988, was the first to adopt
the motion prediction function, making it possible to improvethe brand’s in-focus rate with moving subjects. The principleof the motion prediction function is shown in Figure 6-25. The
motion prediction function derives a regression line from

Pentaprism

multiple distance measurement data to calculate the speed of
the subject at the time of shutter release, predicts the distanceto be traveled over the camera's unique release time lag, anddrives the lens to the corrected subject distance. Since it isexceedingly difficult to reduce the shutter time lag to 40 ms orless in SLR cameras due to the SLR principle, this technology

PN liquid
crystal plate

became an indispensable feature of subsequent AF SLRCorrection
amountDistance fromsubject

cameras and was widely used in popular models.

Light guide
ScreenFigure 6-24 Exploded View of PN Liquid Crystal Display

Time(3) Electrochromic element
The Nikon F5, released in 1996, was the first to adopt anelectrochromic (hereinafter EC) element as an on-screen
display. EC elements combine thin films of iridium oxide andthe like to electrically change the concentration. Unlike liquid
crystals, EC elements are in an all-solid-state, so there is noneed for sealing portions or the like, making it possible toensure a wide frame. Furthermore, EC elements have a higher
transmittance than LCD elements, resulting in the additional
advantage of maintaining the brightness of the frame evenwhen used with a viewfinder. Although not adopted in AF
point displays in subsequent SLR cameras due to an inability
to display luminescence and poor response at low temperatures,Time lagRelease timing Exposure

Figure 6-25 Explanatory View of Motion Prediction(2) Higher speed
Advancesinmicrocomputers

reducedthecalculation time for distance measurement data and made it
possible to handle more complex algorithms. At this same time,
the performance of the motors used to drive the lenses
improved, and the hardware significantly increased in speed.
Especially in sports photography, where high speed is required,ultrasonic motors were commonly installed in the telephotolenses used. Photo 6-63 shows examples of two types ofultrasonic motors: a ring type and a micro type.

EC elements are capable of high-quality display and can beapplied to grid line displays and the like that do not require
responsiveness.

100

greatly

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

2)
3)
4)

Photograph 6-63

Examples of Ultrasonic Motor27)

The ultrasonic motor is based on the principle that a stator
machined into a comb shape is crimped onto a rotor, and a
traveling wave is generated by a piezoelectric element attachedto the backside of the stator to rotate the rotor. Although notsuitable for high-speed rotation, the high torque makes a speed
reduction system unnecessary and the quietness makes itsuitable for lens driving. The ultrasonic motor was adopted by
Canon in their super-telephoto lenses and subsequently, withthe micro type, in other lenses, and by Nikon in their supertelephoto lenses mainly used for sports coverage.
(3) Other AF-related technologies
Just before the beginning of the 21st century, cameras
underwent a drastic shift from silver halide to digital, but
technologies related to AF were still in the process ofdevelopment and continued to steadily evolve. With thedevelopment of multiple AF points, a faster AF drive andincreased computing power, functions for supporting thephotographer in following a subject and functions forautomatic tracking were developed, to name a few.
In addition, there have been proposed technologies thatcombine the selected AF point with information related tosurrounding points to obtain an apparently large distancemeasurement area for a subject in motion and technologies that
automatically select the AF point on the camera side. There arealso technologies that capture not only an image of the subject,
but also color and other unique information, and utilize thisinformation to identify the main subject. These improvements
were made possible by the development of CCD and CMOS
sensor technology used for AF sensors as well as byimprovements in microcomputer processing speed for
calculating huge amounts of data at high speed to derive
optimal distance measurement results.
References and citations
1) Ogura, Iwao. Kokusan Kamera Kaihatsu Monogatari[The Story of Camera Development in Japan], (Asahi

5)

6)
7)
8)

9)
10)
11)
12)
13)
14)
15)
16)

17)
18)
19)
20)

21)
22)
23)

24)
25)
26)
27)

Shinbun Publications, 2001), pp. 130-134.
Nakagawa, Tadashi. Seikosha Shattā Monogatari [TheSeikosha Shutter Story], (Asahi Sonorama, 1998), p. 88.
Nikon F4 Tekunikaru Gaido [Nikon F4 Technical
Guide], (Nikon, 1998), p. 10.
Shashin Kōgyō Bessatsu Nikon F5 Tekunikaru
Manyuaru [Nikon F5 Technical Manual], (Shashin
Kōgyō Shuppansha, 1997), p. 40.
Shashin Kōgyō Bessatsu Nikon Tekunikaru Manyuaru(Zōhoban) [Nikon Technical Manual (augmented
edition)], (Shashin Kōgyō Shuppansha, 1982), p. 51.
Nikon FA Catalog, (Nikon, 1984), p. 5.
Uli Koch. Nikon 100 Anniversary, (OstLicht, 2016), p.
306.
Shashin Kōgyō Bessatsu Nikon Tekunikaru Manyuaru(Zōhoban) [Nikon Technical Manual (augmented
edition)], p. 54.
Nikon F3 Catalog, (Nikon, 1981), p. 4.
Canon New F-1 Catalog, (Canon, 1985), p. 9.
Kamera Kodawari Dokuhon [In Pursuit of the Camera]
2001-2002 (Mainichi Shimbun, 2001), p. 194.
Nikon Exhibition Pictorial Record (JCII Camera
Museum, 2003), p. 14.
Orinpasu no Subete [Everything Olympus], (EiPublishing, 2001), p. 16.
Olympus M-1 Catalog, (1972), p. 9.
Shashin Kōgyō Bessatsu Nikon F5 Tekunikaru
Manyuaru [Nikon F5 Technical Manual], p. 46.
35-miri AE Ichigan-refu Zenchōsa [35 mm AE SLR
Complete Survey], (Shashin Kōgyō Shuppansha, 1981),
p.193.
Manyuaru Kiyanon no Subete [Full Canon Manual],(Ei-Publishing, 2001), p. 48.
Manyuaru Kiyanon no Subete [Full Canon Manual], p.
50.
Shashin Kōgyō, May 1959 (Shashin Kōgyō
Shuppansha), p. 458.
Shashin Kōgyō Bessatsu Nikon Tekunikaru Manyuaru(Zōhoban) [Nikon Technical Manual (augmented
edition)], (Shashin Kōgyō Shuppansha, 1982), p. 79.
Nikon F3 Catalog, p. 8.
Nikon F3 AF Catalog, (Nikon, 1984), p. 10.
Ogura, Iwao. Kokusan Kamera Kaihatsu Monogatari[The Story of Camera Development in Japan], pp. 199207.
Ogura, Iwao. Kokusan Kamera Kaihatsu Monogatari[The Story of Camera Development in Japan], p. 181.
Nikon F5 Catalog, (Nikon, 1997), p. 6.
Nikon F100 Catalog, (Nikon, 1998), p. 5.
NIKKOR Lens General Catalog, (Nikon, 2009), p. 5.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –

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National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

7

In Lieu of an Afterword

It has been a long time since cameras transitioned fromsilver halide to digital. The Casio QV-10, which is said to be
the first digital camera to become popular, was released in
1995. It was around that time that the rapid shift to digital
cameras began, and even SLR cameras have now mostly been
replaced by digital cameras.
However, a second look at the structure of the digital SLR
camera reveals that the elements, other than the film feedmechanism, are an extension of the SLR cameras of the silver
halide era. For example, the focal-plane shutter, the quick
return mirror, the pentaprism ....
These are the result of improvements made by many camera
designers, both famous and unknown, over half a century ago,
and in some cases more than 100 years ago. This document isa systematic analysis of such technologies and the productsthat incorporate them.
The history of photography is nearly 200 years old, but it issafe to say that the first compact precision camera was the
Leica, created by a genius in poor health, Oskar Barnack, about
100 years ago. The Leica was so groundbreaking that it seems
few other industries have been able to create a product withsuch a high degree of perfection from the start.
At the end of 2016, the Center of the History of JapaneseIndustrial Technology of the National Museum of Nature andScience asked me to conduct a systematic analysis on thesubject of “the mechanical camera.” When I heard this theme,
the first thing that came to mind was the Leica. I had been in
charge of camera mechanism design for a long time, so I
thought I could manage the topic. I also wanted to do somepersonal research on the Leica and Barnack, so I tentatively
agreed to the project. Later, upon confirmation, I found out thatthe topic was the mechanical camera (that is, the silver halide
camera) as opposed to the digital camera. The history of thesilver halide camera can be traced back to the Edo period(1603-1868), and conducting a comprehensive systematic
analysis on such a topic would be extremely daunting.
I was also told that two people had already declined theoffer and that the museum had no more options. The fact thatboth of those who declined the offer had authored numerous
books on camera-related topics and were senior members in
the field with whom I was well acquainted also added to thepressure.
With my retreat cut off and the theme unexpectedly heavy,
2017 dawned dark and gloomy. With no other options, thedecision was made to limit the theme to areas of familiarity
and, as was my first thought, to limit the topic to the focalplane shutter models starting from the Leica (though some
exceptions were made in the end). The event that had thebiggest impact in the history of the camera was the birth of the
Leica, and it is an undeniable fact that the Japanese camera
industry since then has been strongly influenced by the Leica.

The purpose of this systematic analysis is not only toinvestigate the history of technological development, but also
to document the cultural background and the state of
manufacturing in Japan. I would be grateful if you would agree
that I have humbly served my purpose in touching on how theculture of the compact precision camera, starting with the
Leica, developed in a way that shook and wove together thelatent technical sense and manufacturing sensitivity of theJapanese people. In this respect, I was able to advantageously
draw on my experience in camera mechanism design andproduction engineering since I joined the company.
In retrospect, the innovative Leica, with its streamlined
layout and astonishing mechanisms that later changed thecourse of the photographic industry, might not have even beencommercialized without the recession that accompanied
World War I. The Contax I, made by Zeiss Ikon under theumbrella of the Carl Zeiss Foundation and based on theconcept of an ideal camera achieved through thorough study
and further enhancement of the Leica mechanism, of course
would not have emerged, nor would the famous and unknown
Leica copies have been born in an island country far to the East.
Compact precision cameras were deeply involved in WorldWar II and related events, such as the February 26 Incident andthe Sorge incident. The Leica-type cameras, which werehighly portable, robust and reliable, had many military
applications, including copying classified documents,
reconnaissance and aerial photography. As the availability ofLeica cameras became more difficult, countries began todevelop their own Leica copies, which marked the dawn of thecompact 35 mm format precision camera in Japan.
The Korean uprising also had a significant impact on
Japanese cameras. The excellence of the Japanese lenses
became known through the unassuming test shots taken byforeign news photographers who were in Tokyo to prepare for
their coverage, and the reputation of the lenses grew
dramatically.
However, the Leica M3, introduced in 1954, was a
breakthrough that far surpassed even the old Leica at its
pinnacle. Japanese manufacturers, realizing that they shouldhave caught up, shifted their development focus to SLR
cameras, which proved to be successful, and in the late 1950s,
new products blossomed one after another, with dramaticdevelopment beginning in the 1960s.
Tossed about by the turbulence of these tumultuous times,
compact precision cameras continued to evolve in Germany
and Japan.

Systemized Survey on the Development and Practical Application of Compact Disc (CD) Technology103

In delving into the theme, I considered various approaches,
including

product

concept,

internal

and Portugal.

mechanisms,

The camera industry then reached a turning point in thespecifications, manufacturers, various technologies anddigital age. The Leica brand has been revived like a phoenix indesigners and, while I proceeded to write without yet having ahigh-end digital cameras through its partnership withclear idea of these, I tried to present the personalities of thePanasonic.

designers as much as possible. This is due to the advice I

manufacturing base in Wetzlar and continues to produce the M

received from my former boss: history is made by people – ifseries, which is more expensive but still carries the Leica blood.

The

company

returnedtoits

traditional

you are going to write about history, include names. Indeed,

Currently, its flagship product is a high-end mirrorless

the Leica is the “Barnack camera” born from the genius ofcamera. Although the camera can no longer be called a

Oskar Barnack, and the designs of cameras that made history

rangefinder camera because an optical rangefinder is no longer

are filled with the ideas and human touch of the people

needed, the mirrorless camera, which can measure distances

involved, such as Kueppenbender for the Contax and Yoshidausing an imaging element and is without mirrors or a

Gorō for the Kwanon Camera, both cameras being designed

pentaprism, can in a sense be considered to be in the ultimate

with the Leica in mind.

position of solving the shortcomings of both the rangefinder

Even in the SLR era, one notices a strong link between thecamera and the SLR camera.

product and its designer: Fuketa and Matsunaga for the Nikon

I can only wonder how the thoughtful eyes of Barnack lying

F, Kawase for the Topcon RE Super, Yoshida for the Asahiflex

in Wetzlar would view the Leica, which at one time sufferedand Maitani for the Olympus M-1.

from the launch of an offensive by the silver halide SLR

Although I spent only a little less than 30 years as a designer

camera, making a comeback with mirrorless cameras and now

in the 100-year history of the compact precision camera since

becoming a strong competitor to Japanese digital SLR cameras.

the birth of Leica, I wanted to introduce the cameras by getting
as close as I could to their design philosophy as someone who

Acknowledgments

was involved in the camera design process.
I must apologize for not being able to make a

I would like to express my deepest gratitude to thefollowing organizations and media outlets forcooperation in providing valuable materials and photographic

for not being able to write about electronics and optical

data for the writing of this document.

technology due to my limited knowledge of the subject. In•

Japan Camera Industry Instituteaddition, there are so many excellent literature and research•

JCII Camera Museum

books on the Leica and SLR cameras that it was impossible to•

Leica Camera Japan Co., Ltd.

read and digest them in a very limited time. As a result, it is•Canon Camera Museumwith a degree of trepidation that I reread this document and•Canon Marketing Japan Inc.

found it incomplete and rambling, but I hope that it will be of•

Yamato Museum

some help as a systematic survey on the compact precision•

Nikon Corporation

camera from the perspective of a camera designer.

I would also like to express my deepest gratitude to the

Finally, I would like to note what happened to the Leica.

following persons for their valuable information and warm

After being late to the SLR competition and the originaladvice on the technology and history of cameras and shutters.

rangefinder models became more expensive due to rising fixed•

Mr. Sato Akihiko and Mr. Toyoda Kenji (ex-Nikon)

costs in Germany, Leitz was forced to move its production to•

Mr. Nakagawa Tadashi (ex-Seiko Precision)

Portugal and Canada. With the help of Minolta and Copal, the•Mr. Takahashi Shigemi (Nidec Copal Corporation), Mr.

Leitz family entered the SLR camera market, but it was not

Inoue Nobuyoshi (ex-Nidec Copal Corporation)

enough to turn the business around, and the Leitz family soldI would like to express my deepest gratitude to theits holdings to the Swiss company Wild and the company

following persons for their kind cooperation and provision of

became its subsidiary. Camera production at the Wetzlar

access to related books, documents and literature.

factory, which had been associated with Barnack, was halted,•

and the tradition was hanging by a thread. There was a time
when I, as a camera enthusiast, spent many gloomy days
wondering if the day would finally come when cameras of the

104

their

comprehensive mention of even domestic SLR cameras, andMr. Miyazaki and Ms. Yoshida, JCII Library, Japan
Camera Industry Institute•

Mr. Itō, Secretariat, Camera & Imaging Products
Association

Leica brand would no longer be produced. Nevertheless, theIn addition, I would like to take this opportunity to express

Leica brand kept its vitality by changing the company namemy deepest gratitude to all those who have given theirfrom Ernst Leitz to Leica and later to Leica Camera, andcooperation, both tangible and intangible, in matters related to

products continued to be produced in small quantities in Solms

this document, without which the writing of this document

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 Marchwould not have been possible.

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –105

Camera-related ISO standards
ISO
516
517
518
519
1007
1203
1222
1229
1230
1754
1948
2720
2721
2800
2827
3028
5763
6053
6516
6728
8478
8581
10157
10330

Name
Camera shutters – Timing
Apertures and related properties pertaining to photographic lenses – Designations andmeasurements
Camera accessory shoes, with and without electrical contacts, for photoflash lamps andelectronic photoflash units
Hand-held cameras – Flash-connector dimensions
135-size film and magazine – Specifications
Roll film cameras – Back window location
Tripod connections
Expendable photoflash lamps – Determination of light output
Determination of flash guide numbers
Cameras using 35 mm film and roll film – Picture sizes
Front lens barrels up to 127 mm – Dimensions important to the connection of auxiliaries
General purpose photographic exposure meters (photoelectric type) – Guide to productspecification
Cameras – Automatic controls of exposure
Expendable photoflash lamps – Definition and evaluation of flashability
Electronic flash equipment – Determination of light output and performance
Camera flash Illuminants – Determination of ISO spectral distribution Index (ISO/SDI)Electronic flash equipment – Automatic control of exposure
Shutter cable release tip and socket – Dimensions
Photographic lenses – Distance scale marking
Camera lenses – Determination of ISO colour contribution index (ISO/CCI)
Camera lenses – Measurement of ISO spectral transmittanceElectronic flash equipment – Connectors to synchro-cord
Flash exposure meter – Requirements
Synchronizers, ignition circuits and connectors for cameras and photoflash units – Electricalcharacteristics and test methods

Camera-related Japanese Industrial Standards (JIS)
JIS B

Name

7091
7092
7094

Shutters for still cameras
Photoelectric methods for measuring light exposure in focal planes of cameras
Photographic lenses – Measurement of the focal length
Photographic lenses – Methods for the measurement of the effective aperture,
F-number and relative aperture
Determination of ISO Colour Contribution Index (ISO/CCI) of Camera Lenses
Photography – Camera Flash Illuminants – Determination of ISO Spectral
Distribution Index (ISO/SDI)
Camera Accessory Shoes and Feet
Socket and plug for camera flash synchronization
Tripod Connections for Cameras
Shutter cable release tips and sockets for cameras
Photographic lenses – F-number marking
Photography – Camera lenses – Measurement of ISO spectral transmittancePhotographic lens – Front lens barrels up to 127 mm – Dimensions important tothe connection of auxiliaries
Picture Sizes for Still Cameras

7095
7097
7098
7101
7102
7103
7104
7106
7107
7111
7115

Japanese Camera Industrial Standards (JCIS)
JCIS
2
3
4
8
9
10
24
25
26
27
28
29

106

Name
Kamera no dōchō hakkō kikō soketto oyobi puragu-yō genkai gēji [Limit
Gauges for Camera Synchronized Flash Mechanism Sockets and Plugs]
Kamera no sankyaku toritsukebu-yō gēji [Gauges for Tripod Connections
for Cameras]
Kamera no rerīzu-yō gēji [Gauges for shutter cable release]
Seimitsu kiki-yō neji jūji ana (0-ban) [Cross-Recess for Machine Screws for
Precision Instruments]
Seimitsu kiki-yō jūji neji-mawashi bitto (0-ban bitto) [Screwdrivers for Cross
Recessed Head Screws for Precision Instruments]
Seimitsu kiki-yō jūji ana-tsuki koneji (0-ban koneji) [Cross-Recessed Head
Machine Screws for Precision Instruments]
Kamera no richiumu denchi kōkan hyōji hōhō [Camera lithium battery
replacement indication method]
Kamera no kigō E ni yoru sōsa hyōji hōhō [Camera operation display
method by symbol E]
Kamera no gurafikarushinboru [Camera graphical symbols]
Kamera no shitsuryō oyobi sunpō no hyōji hōhō [Method of indicating themass and dimensions of a camera]
Bōsui kamera no shurui to hyōji [Types and method of indicating waterproof
cameras]Shashin-ki nado ni shiyō suru mētoru hosome-kei neji [Metric fine threads
for photographic equipment, etc.]

Corresponding JIS
B7091
B7094, B7095, B7106
B7101
B7102
B7103
B7115
B7111

B7098
B7104
B7097
B7107

Year ofpublication
1971
1973
1978

Most recent Corresponding
revision
ISO
1992
516
–
2721
1997
517

1978

1997

517

1986

–

6728

1988

–

3028

1952
1952
1952
1952
1952
1969

1975
1995
1975
1992
1997
1997

518
519
1222
6053
517
8478

1954

1997

1948

1955

1975

1754

Year ofpublication

Most recent
revision

1963

–

1963

–

1963

–

1970

–

1970

–

1970

–

1993

–

1995

–

1997

–

1997

–

1997

–

1997

–

National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25. 2018 March

Note
Corresponds to JIS
B 7102
Corresponds to JIS
B 7103
Corresponds to JIS
B 7104JCIS 8-10 are
combined volumes.

1870

Konishiya Rokubeiten
Konishi Honten

Transitions of
manufacturers

1880
1890

Japanese

35mm

focal-plane

shuttercamera• “Corporation” is omitted• (LLC) is a limited liability company• (Ltd.) is a limited company• Meguro Kōgaku , Tanaka Optical, Daiichi Kōgaku, Mejiro Kōgaku, Zuihō Optical, Reise
Kōgaku, Misuzu Kōgaku Kōgyō and the like also manufactured 35 mm focal-plane cameras,
but details are unknown and therefore omitted.

1900(Established Rokuosha)

Kuribayashi Seisakusho

1910

Merged parts of Tokyo Keiki, Iwaki Glass and Fujii
Nippon Kogaku Kogyo
Asahi Optical (LLC)

Takachiho Seisakusho

1920

Konishiroku Honten

Nichi-Doku Shashinki Shōten(Japan-Germany Camera
Company)

Katsuma Kōgaku Kikai and surveying
instrument factory of Seikosha merged

Kuribayashi Camera
MOLTA (LCC)

1930

Teikoku Kōgaku Kenkyūjo
Tokyo Optical
Precision Optical Instruments Laboratory
Japan Precision Optical
Instruments Laboratory

Riken Kankōshi
Konishiroku

Chiyoda Kōgaku Seiko

Fuji Photo Film

Precision Optical Industry
Asahi Optical Riken Optical

EnomotoKōgaku Seiki
Manufacturing
Kōgaku Seikisha
made into
subsidiary

Kyōei-sha
Shōwa Kōgaku (LCC)

1940

Mamiya Kōki Seisakusho

Takachiho Optical

Konishiroku
Photo
Industry

Fuji Photo Optical
Olympus Optical
Shōwa Optical Works

Nippon Camera
Canon Camera

Orion Seiki Sangyō (Ltd.)Sanshin Seisakusho
Yashima Seiki
Mamiya Optical

1950

Nicca Camera
Sanshin Seisakusho (Ltd.)Sanshin Seisakusho K.K.
Yashima Kōgaku Seiki
Teikoku Kōgaku Kōgyō
Zunow Opt.
Orion Camera
Yashima Optical
Miranda Camera
Yashica
Nikō

Leotax Camera

1960

Petri Camera

Minolta Camera

Taiho Optical

Absorption andmergerSanshin Kōgaku Kōgyō

Ricoh

Absorption andmergerCanon
1970

Leitz alliance

ChinonPartnership with the Carl
Zeiss Foundation

CosinaPetri Kōgyō

1980

Merged with Kyocera
Withdrew fromcamera business
KonicaNikon
Topcon1990

Withdrew from camera
business

Merged with Olympic
Mamiya-OP

Minolta

2000

Pentax
Konica Minolta

OlympusMerged with Kodak
Japan Digital ProductDevelopment

Fujinon(Transferredcamera business to

2010(Integrated
management with
Hoya)

Fujifilm

Withdrew from camera
business

Mamiya Digital Imaging

Hoya camera
businesstransferred to
Ricoh

Systematic Survey on 35 mm High End Camera – History from Leica to SLR –

107

108
National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25 2018. March

Product transitions of 35 mm compact precision camera (focal-plane shutter camera and SLR)
Brand/Company
name

1910s

1920s

1930s

Ur-Leica (prototype)

1940s

Standard

1950s

IIIc (die-casted)

1960s

IIIf (with synchronizer)

1970s

IIIg (M3-type viewfinder)

Null Leica (prototype)

Leica

1990s

2000s

R3 (Minolta XE based)

SL (TTL metering)2010s

R8 (in-house design)

R4 (Minolta XD based)

II (coupled rangefinder)
III (slow shutter speed)
I (B) (lens shutter
camera)I (C) (interchangeable
IIId (self-timer)lens)

CL (Minolta manufactured, vertically traveling shutter)M5 (built-in light-receiving
element)

M3 (automatic frame switching, parallax correction,bayonet mount)

Contarex I

Contax I (louver-type shutter, long baseline length, bayonet mount)Carl Zeiss

1980s

Flex I (external metering)Contax II (reduced in size)

Contax IIa (reduced in size)
Contaflex I (lens shutter camera)
Contax S (with pentaprism)

Kine Exakta

Other international(described in thisdocument only)

Exakta Varex (viewfinder interchange)

FED

Retina Reflex (lens shutter camera)

Duflex (eye-level viewfinder, quick return mirror)

SPORT (first 35 mm SLR)

KardonPraktica (M42 mount)Rolleiflex SL2000F (film back replacement, waist/eye-level switchable viewfinder)

Bessamatic (lens shutter camera)

Reid III△Zorki

Kodak Ektra (film back replacement)
Asahiflex I (first 35 mm SLR in Japan)

Asahi Pentax ES (AE)Asahiflex IIB (quick return mirror)

Asahi Optical
PentaxPentax ME-F (FA)Asahi Pentax K2 (K mount)

Asahi Pentax (with pentaprism)

Pentax Z-1

Asahi Pentax MX (small, lightweight)

Asahi Pentax S2Asahi Pentax ME
Asahi Pentax SP (TTL metering)

35 I (24 x 32, 4-shaft FP shutter)

Pentax MZ-5
Pentax SFX (full-scale AF)

Leitz Minolta CL (Leitz design)

35II (24 x 36 format)

Pentax MZ-S

Pentax Super A (dual-priority AE)

Pentax LX

Pentax *ist

α-7700i (AF multipoint)

CLE (curtain surface metering)X-1 (professional AE camera, viewfinder interchange)

SR-2 (Minolta’s first 35 mm SLR)

Minoltaα-7000 (full-scale AF, full automation)
SR-7 (external light exposure meter)

α-9xi (with 1/12000)

XD (dual-priority AE)

SR-T101 (pattern metering)
PEN-F (half-size SLR)PEN FT

M-1 (small, lightweight)

OM-4 (multi-spot metering)OM-2 (curtain surface metering, direct metering)
FTL (M42 mount)

Olympus

OM2000

OM101 (power focus)

OM10
OM707 (full-scale AF)

OM20
OM30 (FA)OM40
I (24 x 32 format, bayonet mount)

F (quick return mirror, viewfinder interchange, frame coverage 100%)

Nikomat FT

S2 (24 x 36, winding lever type)

F3 (first F single-digit AE)

F2 (high functionality, highreliability)
Nikomat ELW

S (24 x 34 format)
F Photomic TN

SP (6 types of viewfinders)F5 (8 fps, 5-point AF)

NIKONOS RS AF (underwater SLR)

FM (reduced in size)

Nikon

F4 (automatic winding, AF)

FA (multi-pattern metering)
F-301 (automatic windup)

Nikomat EL (aperture-priority AE)

S3 (reissue)

F-501 (full-scale AF)

Nikomat FTn

SP (reissue)

F-401 (built-in flash)
EM (AE dedicated camera)

F2 Photomic

F100 (Mg cover)F-801 (with 1/8000)

FM2 (with 1/4000)
FG (program AE)

Flex (trigger lever winding)Hansa Canon

F-1 (viewfinder interchange, high reliability)

T50 (automatic winding)
T70 (large-size LCD)FX (external light metering)

PELLIX (fixed pellicle mirror)

AE-1 (CPU built-in, reasonably priced camera)
A-1 (dual-priority AE)

Canon

P (high CP)
IV Sb2

NipponNicca
Yashica
Contax
KyoceraEOS-1 (automatic winding AF)

New F-1 (high systemability)

Flex R2000

EXEE (front group interchangeable lens)

Nicca IIIL
Nicca 4

RTS (Yashica’s first Contax brand)

Yashica Penta J-5

Nicca 33

Nicca III

EOS620 (new mount, full-scale AF)

Yashica Penta J

Nicca 5
Nicca

T90 (advanced design, high-speed continuous shooting)

7 (50/F0.95 lens)Yashica FR

Yashica TL Electro X

Yashica YF

N1 (new mount)

RTS II Quartz

139 Quartz

Yashica TL Super

137 MD quartz (automatic winding with built-in motor)

Yashica Pentamatic

137 MA Quartz

AX (back-focusing AF)

167 MT (with auto-bracketing)Yashica FX-3 Super

Aria

Kyocera 230-AF (full-scale AF, compatible flash)
F (metal blade FP shutter, 1/2000)

KonicaHexar RFFS (vertical traveling shutter)

FS-1 (built-in motor)

Autorex (external light AE, half-size switchable)
FTA (shutter speed priority AE)
R (semi-automatic aperture)

TopconSuper DM (optional winder available)

R II (automatic aperture)
RE Super (mirror meter, TTL full aperture metering)

FT-1 Motor

ST701 (SPD adoption)
ST801 (LED display)

FujicaFuji

AX-5 (new mount, dual-priority AE)

TX-1 (24 x 65 size changeable)

ST901 (LED digital display)
Leotax (original)

LeotaxSpecial A/B
SpecialSpecial D III
Singlex TLS

XR-S (equipped with solar cell)

Flex LS401 (waist/eye-level switchable viewfinder)

Ricoh

XR-1 (K mount adopted)

PENTA

PENTA V3PENTA V6 (reasonably-priced camera)

PENTA VPetri

XR-X (automatic winding without sprocket)

PENTA V2
Flex 7
Prismat CLP (export only)
Prismat NP

MamiyaSekor Auto XTL

ZE-2 quartz (mount with electrical contacts)

Sekor 1000 DTL

Prismat WP (dedicated mount)Prismat CP
Sekor 1000S
T (built-in pentaprism)
B (quick return mirror)

MirandaSensomatSensorex EE

Automex III
Sensorex (TTL metering)
Chiyoca 35

Zunow (open aperture, quick return mirror, viewfinder interchange)

Ichicon-35

Other Japanese
focal-plane shutter
camerasChinon CE-3 Memotron (K mount)

Honor S1

Zeiss Ikon

Chinon CE-4

Chinon M-1

Yasuhara Isshiki

Osanon (Yashima) Digital 750
Honor SL

Bessa L
Bessa T

Cosina T-1

Tanack 35 IIC

Bessa R2

Cosina Hi-Lite EC
Tanack VP

Bessa R3M
Bessa R4A

MelconSystematic Survey on 35 mm High End Camera – History from Leica to SLR –Firstflex 35 (lens interchangeable)
Pentaflex 24x36 (penta mirror)
Topcon PR

Topcon Uni (TTL-AE)

Topcon PR II

Topcon Unirex
Topcon Wink Mirror (quick return mirror)

Topcon Wink Mirror S (lens replaceable)
Aires Penta 35 (automatic aperture)
Topcon Unirex EE

Domestic lens
shutter SLR camera

Early Bridge
CameraNote•△ indicates a rangefinder camera, and ▲ indicates an SLR
camera.
•For cameras with different launch years in Japan and overseas, theearlier date was indicated.
•
Major brand names are omitted to avoid complications, but
indicated in the case of possible confusion.
•
Models not described in this document are also included.
•
Not all models are covered; only major models.
•
To avoid complications, the following abbreviations are used.
FP: Focal-plane
AF: Autofocus
FA: Focus-aid•
Most overseas products have been omitted except for thosementioned in this document, but those of Leitz have been included
to the extent possible.
•
Domestic foreign brands such as Zeiss Ikon and Bessa wereconsidered domestic.
•
So-called early bridge cameras often have focal-plane shutters, butclassified in a different category.

Kowaflex

Fujica ST-F (built-in flash)Kowa SETR

Kowa E

Kowa UW190 (19 mm lens)
Kowa H (external flash AE)
Kowa SE

Nikkorex 35 (Porro mirror)
Nikkorex 35-II
Nikkorex Zoom 35 (with zoom lens)
Nikon Auto 35
Ricoh 35 Flex
Canonex
Mamiya Prismat PH
Mamiya Family
Minolta ER (for export only)
Fujicarex II (for export only)
Olympus L-1
Olympus L-2
Olympus L-10
Ricoh MIRAI
Kyocera Samurai (halfOlympus L-10 Super
size)
Kyocera Samurai Z
Olympus L-20
Kyocera Samurai Z2

Kyocera Samurai Z-L (left-handed)
Chinon Genesis
Chinon Super Genesis

Olympus L-30
Olympus L-5

109

110
National Museum of Nature and Science Survey Reports of Systematization of Technology, Vol. 25 2018. March

35 mm compact precision camera
No.

1

2

3

4

5

6

7

Name

Industrial technology history material
Location

Material TypeHansa Canon

Camera Industry Institute, JCII
Camera Museum
25 Ichibanchō, Chiyoda-ku

Prototype

Asahiflex

Camera Industry Institute, JCII
Camera Museum
25 Ichibanchō, Chiyoda-ku,
Tokyo

Mass produced
product

Nikon F

Nikon Museum
2-15-3 Konan, Minato-ku,
TokyoShinagawa Intercity Building C

Topcon RE Super

Camera Industry Institute, JCII
Camera Museum, 25
Ichibanchō, Chiyoda-ku, Tokyo

Olympus M-1

Hachioji Office, Olympus
Corporation
Olympus Technology History
Museum, “Zuikodo”
2951 Ishikawa-machi, Hachioji,
Tokyo

Canon AE-1

Canon Inc.
3-30-2 Shimomaruko, Ota-ku,
Tokyo

Minolta α-7000

1 Sakura-machi, Hino-shi,Tokyo
ReleaseKonica Minolta Tokyo Site Hino commemoration
Konica Minolta With You, Inc.

Mass produced
product

Mass produced
product

Mass produced
product

Mass produced
product

Location confirmed

Current State

Created by

Created Year

Reason for Selection

Note

On display

Precision Optical
Limits Laboratory(currently Canon)

1935

Japan's first 35 mm rangefinder camera with focal-plane
shutter.
This was a monumental product that was not merely an
imitation of the Leica, but also marked the beginning of thecompact precision camera made in Japan, with its unique lens
mount, film counter on the front and unique pop-up viewfinder.

Product No. 1119
With Nikkor 50 mm F3.5
(No. 129)

On display

Asahi OpticalCo., Ltd.
(currently Ricoh)

1952 (Year of
product release;year ofmanufacture notyet confirmed)

The first domestically produced 35 mm SLR camera.
The unique screw mount permits interchangeable lenses, andthe semi-quick return function eliminates the disadvantage of
the SLR camera (loss of viewfinder image after shooting) byreturning the mirror by release of the shutter release button.

Product No. 26274
With Takumar 50 mm
F3.5 (No. 26207)

On display

Nippon Kogaku
Kogyo Co., Ltd.
(currently Nikon)

On display

Tokyo OpticalCo., Ltd.
(currently
Topcon)On display

In storage

In storage

1959

An SLR camera that quickly gained a reputation forfunctionality, quality and systemability.
With its advanced lens mount, quick-return mirror, open
Product No. 6400028
aperture and interchangeable viewfinder, the camera has
become the reigning professional and high-amateur camera forover 15 years.

1963

A 35 mm SLR camera with pioneering features such as TTL
open-light metering and a mirror meter.
In addition to its graceful design, the camera also deserves
praise for its high systematics, including the commercializationof a 300mm F 2.8 large-aperture lens and a retro-focus wideangle lens.

Olympus OpticalCo., Ltd.
(Currently
Olympus)1972

A 35 mm SLR camera with an astonishingly compact andlightweight design achieved by completely rethinking theinternal mechanisms and layout.
Despite its compact size and light weight, the camera maintains Product No. 100471
a high level of systematics and enhanced basic performance,such as the inclusion of an air damper, and established theideal SLR camera for the future.

Canon

1976 (Year of
product release;year ofmanufacture notdisclosed)

Minolta (currently
Konica Minolta)

1985

A 35 mm SLR camera with advanced functions andspecifications achieved through digitization while keeping theselling price low.
Provided with a low-cost integrated dedicated winder, theproduct was an unprecedented hit with the catchphrase,“Rensha-ichigan (Continuous shooting SLR) camera.”

Product No. 4601021
With RE AUTOTOPCOR 5.8 cm F1.8
(No. 99007265)

Product No. 357856

The first interchangeable-lens SLR camera to realize a fullfledged automatic focusing function. This innovative product,
Product no. 10000002
which changed the trend of the 35 mm SLR camera in a single
With AF70-210 mm F1.4
stroke, was the result of a complete rethinking of the(No.10000002)
conventional product form and the almost complete automationof functions, including the system itself.