From: erf@progress.COM (Eric Feigenson)
Subject: Re: New Nikon camera!!!
Organization: Progress Software Corp.
Date: Tue, 1 Sep 1992 14:57:48 GMT

Here are the press releases for the new Nikon N90 body and SB-25
flash:

                    NIKON INTRODUCES N90 CAMERA SYSTEM

             FEATURING 3D MATRIX METERING, WIDE-AREA AUTOFOCUS
                  Compatible with Nikon F-Type Lens Mount

MELVILLE, N.Y., Aug. 26, 1992 -- Nikon Inc. today introduced the new
Nikon N90 35mm SLR camera system with advanced new technology designed
to inspire a photographer's creative ability and extend picture taking
opportunities.

The N90 reaffirms Nikon's commitment to System Integrity, through its
continued use of the Nikon F-type lens mount. Integral with System
Integrity is Nikon's continued drive to enhance picture taking
potential. The new Nikon N90 and its system components establish new
standards of performance through their special features such as Wide
Area Cross-Type autofocus; 3D Matrix Metering, the world's first
5-segment flash sensor for superior flash control; and a speedlight with
monitor pre-flash for distance and reflectance analysis.

N90 will be the first camera to employ the Nikon Data Link
System, integrating the power of a palm-sized information manager with
the N90's operation. (Data Link System scheduled for delivery Summer 93).

According to Richard LoPinto, Division Manager, Nikon Photo Group,
"We've said for many years that Nikon takes the world's greatest
pictures. We're confident that the technical advances of the N90 will
make that statement even more true in the years to come."

Using the Nikon F lens mount, renowned for its durability and
consistently high professional performance, the Nikon N90 is compatible
with all AF Nikkor lenses and Nikkor AI-type lenses. With these lenses,
owners of these lenses will be able to use advanced features of the new
N90, such as the new 8-segment Matrix Light metering, 5-segment TTL
flash control and more.

Together with the N90 camera, Nikon is also introducing new
distance-encoder technology into AF Nikkor lenses. Designated by the
letter "D" in the product description, the new D-type AF Nikkor lenses
make it possible for the N90 to deliver its highest levels of exposure
metering and flash control with 3D Matrix Balanced Fill Flash.

Wide Area Cross-Type Autofocus: The Nikon N90 redefines autofocus
performance standards for precision, consistency and versatility. The
system's autofocus sensor, in-camera computer and new software allows
the camera to operate quickly and accurately in brilliant sunlight and
in light so dim the average photographer can not manually focus.

At the heart of its operation is Nikon's new CAM 246 Wide Area
Cross-Type Focus Detection Sensor. With overlap servo, operation is
fast, reliable and very accurate, even in low light conditions as dim as
EV minus one, or with moving and off-center subjects. The focus
detection area incorporates an extra-wide 7mm horizontal component
combined with a 3mm high vertical detection component, eliminating all
of the "dead spots" found in some systems and allowing for fine details
to be more reliably focused.

When focusing on small areas, the photographer can select Spot
Autofocus, covering approximately one percent of the field of view,
enabling focus on such small areas as a subject's eye in portrait
photography.

Autofocus operates with all AF Nikkor and AF-I Nikkor lenses, each of
which has a built-in CPU that communicates with the N90 computer via
contacts in the F-mount, relaying focus detection and, with D-type
lenses, distance data as well.

Two autofocus modes are provided, Single Servo and Continuous Servo.
Single Servo is designed for quick composition, locking the focus as the
shutter release is pressed. Continuous Servo is designed for following
moving subjects and allows the shutter to be released at any time.

Focus Tracking operates in both autofocus modes. It uses the system's
computer power to predict the point of sharp focus for a moving subject
and focus the lens to the estimated camera-to-subject distance at the
instant of shutter release.

3D 8-segment Matrix Metering:  Nikon was the first company to introduce
a multi-segment metering system to analyze both scene brightness and
contrast. Now, using an all-new 8-segment sensor, enhanced computer
power and special new Nikon software, the N90's exclusive 3D Matrix
Metering can also take distance into account using Fuzzy Logic to
perform expanded levels of light pattern analysis. Its advanced
performance is particularly noticeable in complex, fast changing
lighting situations and with off-center composition.

3D Matrix Metering operates only with D-type AF Nikkor lenses, which
incorporate a distance encoder in the lens. For other AF Nikkor lenses,
Advanced 8-segment Matrix Metering is provided.

The N90 also provides center-weighted metering for creative work and for
use with lenses that do not have a built-in CPU, such as the AI-S
lenses. In addition, there is a spot meter for critical applications,
particularly in laboratory and studio photography.

Versatile Exposure Control:  Programmed exposure sets both f/stop and
aperture automatically. In addition to its versatile multi-program
exposure control, the N90 provides the new Vari-Program, offering a
selection of built-in programs for special situations.

The photographer chooses the program, such as Portrait, Flash Portrait
with Red-Eye Reduction, Hyperfocal program, Landscape Program,
Silhouette Program, Sports Program or Close-Up Program, and the N90
controls exposure to achieve the programmed visual effect.

Other exposure controls built into the N90 are Aperture Priority for
automatic selection of shutter speeds, Shutter Priority for automatic
selection of aperture setting, and Manual exposure control. Manual
exposure compensation is also possible.

The photographer can monitor all exposure control modes and other
critical camera settings using the large, easy-to-read Liquid Crystal
Displays on the camera top and in the viewfinder. Display illumination
is provided for both displays.

5-Segment 3D Multi-Sensor TTL Flash Control:  One of the most
significant developments for flash exposure control since the advent of
TTL (through-the-lens) flash control has been the automation of
fill-flash photography.

Fill-flash combines the ambient light with a flash exposure that is
calculated to fill in harsh shadows and generally brighten and balance
the subject in comparison with the background. The result is a more
pleasing photograph with better rendition of color and detail for the
main subject.

Since Nikon's introduction of Automatic Balanced Fill-Flash, offered in
all of Nikon's Autofocus SLR cameras, the use of fill-flash has expanded
from being a highly limited feature to one that is routinely used to
enhance pictures.

The N90 marks the debut of the world's first 5-segment TTL flash sensor.
The new sensor detects a Matrix-like pattern during the flash exposure
and, through computer and software power, analyzes the scene's
brightness pattern.

Combining multi-segment ambient and flash exposure analysis with encoded
distance information from a D-type AF Nikkor lens and data from the
Monitor pre-flash provided by the new SB-25 speedlight, the system can
deliver 3D Matrix Automatic Multi-Sensor TTL Fill-Flash Control.

In mere milliseconds, this system calculates and executes a perfect
fill-flash picture even when there are headlights, mirrors, or very dark
or distant bacgrounds in the scene.

It also can recognize when there is a very near object between the
camera and the focused subject and compensate accordingly.

The 3D Matrix Flash Metering can even estimate the reflectance of the
subject and compensate automatically for very dark or light subjects and
for unusually dark or light backgrounds.

Non-3D Multi Sensor Balanced Fill-Flash is possible when any AF or AI-P
lens (except those for the F3AF) is used in conjunction with any Nikon
TTL Speedlight.

In addition to Matrix Balanced Fill-Flash, the N90 also provides
Center-Weighted Fill-Flash and Spot Fill-Flash modes.

Built-in flash synchronization options include normal sync from 1/250 to
1/60 sec. (or 1/focal length sec.), slow sync down to 30 seconds, and
rear curtain sync. FP sync up to 1/4,000 sec. is possible with the new
SB-25 AF Speedlight.

New Accessories Provide Advanced Capabilities:  The Nikon N90's
accessories include a new speedlight with advanced capabilities, a
multi-control back and camera programming and information storage and
retrieval using a palm-sized electronic data link, the Sharp Electronic
Organizer.

When used with the N90, this new Nikon Speedlight can provide Monitor
Pre-Flash for 3D Matrix Balanced Fill Flash analysis, Red-Eye reduction
for superior portraits, and Focal Plane flash sync for use with high
shutter speeds from 1/250 sec. up to 1/4,000 sec.

The Multi-Control Back MF-26 significantly expands camera performance by
providing a variety of creative and technical controls. These include
data imprint, a world clock, an interval timer, long exposure timer,
automatic sequence shooting, exposure bracketing, and freeze focus.

A new concept in photo control, the Nikon Data Link System (scheduled
for delivery during Summer 1993), operates with Sharp model 8000, 8200
and 8600 Electronic Organizers using the Data Link IC Card AC-1E
manufactured by Nikon and the Nikon MC-27 Connecting Cord.

On line, it provides a menu for complete remote control operation,
customized program and function settings, memory for shooting data for
each exposure, and control of MF-26 Multi-Control Back Settings. Off
line it provides an abridged instruction manual and photo handbook along
with a utility menu.

Other system accessories include the infrared Modulite ML-3 Remote
Control Set, connecting cords, camera straps, camera cases, and an
external Battery Pack DB-6 for prolonged shooting or work under low
temperature conditions.

Other Camera Features:  The N90 has three automatic film advance modes,
Single Servo for exposure each time the shutter is triggered and two
Continuous modes for action photography situations.

The photographer selects each of the N90's automatic functions using
input buttons and the convenient Command Input Dial. All settings are
displayed on an easy-to-read LCD panel on top of the camera. Selected
settings are displayed on an LCD in the viewfinder. Audible and visual
warning signals are also provided.

Electromagnetically controlled shutter speed range from 1/8,000 sec. to
30 sec. and are stepless in Programmed mode. A "B" setting is provided,
and the camera has a two-shot self timer.

Film speed indexing is automatic from ISO 25 to 5000. Manual settings
are possible from ISO 6 to 6400.

The high-eyepoint finder with BriteView screen makes the screen easy to
see, even in dim light, and clear markings for autofocus and meter
coverage are provided. An optional E-type screen with grid lines is
available, as are optional Nikon eyepiece corrections lenses.

The camera is powered by four, readily-available AA-type 1.5 Volt batteries.

The N90 is ergonomically designed with a built-in battery grip and
excellent balance for comfortable feel and elegant appearance.

The Nikon N90 35mm SLR Camera, SB-25 AF Speedlight, Multi-Control Back
MF-26, AF Nikkor lenses and other accessories are distributed by Nikon
Inc., 1300 Walt Whitman Road, Melville, New York, 11747-3064.
The Nikon N90 camera and accessories will be available through Nikon
Authorized Products Dealers. Price and delivery date to be announced.

(Sharp. is a registered trademark of the Sharp Corporation.)

# # #



          EXCLUSIVE 5-SEGMENT TTL FLASH EXPOSURE CONTROL SYSTEM
               AND 3D MATRIX BALANCED AUTOMATIC FILL FLASH

                FEATURED IN NEW NIKON N90 35MM SLR CAMERA
                      EXPANDED PICTURE TAKING OPTIONS
         WITH ALL CAMERA-COMPATIBLE LENSES AND NIKON TTL SPEEDLIGHTS

           ADVANCED TECHNOLOGY WITH NEW D-TYPE AF NIKKOR LENSES AND
                       NIKON SB-25 AUTOFOCUS SPEEDLIGHT

MELVILLE, N.Y., Aug. 26, 1992 -- The flash exposure control system
introduced in the new Nikon N90 35mm SLR camera is the most technically
advanced of any 35mm camera, to date. It is the first to provide a
5-segment light sensor for TTL through-the-lens) flash control. Control
through this sensor is integrated with inteligent light exposure control
provided through the N90's 8-segment Matrix Metering. The result is
Advanced Automatic Matrix Balanced Fill-Flash.

The N90 system opens up new picture taking possibilities with Nikon's
compatible AF Nikkor lenses and TTL Speedlights. With enhanced computer
power and Nikon's powerful software the system is faster, and provides a
detailed computerized analysis of complex lighting situations.

Even more picture-taking potential is unlocked when a photographer uses
the N90 with one of Nikon's new D-type AF Nikkor lenses, which provide
distance information, and the new SB-25 AF Speedlight, which features
Monitor Pre-Flash. This brand new flash exposure technology makes it
possible to produce 3D Automatic Matrix Balanced Fill-Flash photos in
situations that are still farther beyond the technical capability of
other camera systems.

By combining distance information provided by the D-type lens and
defocus status from the electronic rangefinder with multi-segment light
sensor (ambient and flash illumination) analysis of the scene, the
camera can determine if a centered bbbject has standard reflectance and
compensate the flash exposure. If reflectance is higher or lower than
the standard, it will automatically adjust flash power, so that black
and white will be properly rendered. The system can also automatically
control flash exposure for an off-center subject. The N90 is the first
camerain the world to deliver this level of flash control for advanced
picture taking and automatic balanced fill flash control.

>From the photographer's point of view, what the Nikon N90 offers -- to
an extent far beyond that of any other camera -- is an opportunity to
respond spontaneously to new photo possibilities. With its Wide-Area
Autofocus, Focus Tracking for iiiing subjects, and integrated
multi-segment ambient and flash sensors, the N90 is a powerful system.
With the N90, it is possible to use fill flash to illuminate a subject
moving rapidly between light and dark areas--children quickly moving in
dappled sunlight, a wind-surfer against a sunset sky, a motorcyclist
moving down a neon-lit street, a hang-glider just taking off from a
cliff face, and much more.

                  System Integrity is Significant

Keeping with Nikon's commitment to System Integrity, owners of current
Nikon AF Nikkor lenses benefit from much of the N90's new technology.
This is due in large part to Nikon's commitment to maintain the famous
Nikon F bayonet lens mount. The F-Mount, with its triple-claw bayonet
and electro-mechanical interface maintains the most extensively
compatible system in 35mm photography. In addition, owners of
compatible Nikon TTL speedlights, including the SB-24 AF Speedlight,
will also appreciate that their speedlights can be controlled by the
N90's new multi-segment flash sensor.

            Development of Nikon Multi-Segment Exposure Control

One of the most significant developments for flash exposure control,
since the advent of TTL flash control, has been the automation of
fill-flash photography. Nikon was the first to introduce the
multi-segment Matrix Ambient Light Meter and use it in conjunction with
the TTL flash control system to achieve improved results.

The benefits of fill-flash are extensive, and the resulting photographs
are striking. No other exposure control technique can provide the
improvements that fill-flash does. The method was long used by
professionals, but the techniques necesssary to accomplish a good
fill-flash photo are very complicated and the picture iituations in
which they could be used were very limited. As a result, the technique
was infrequently used. For amateurs, the use of fill-flash was almost
non-existent. Nikon Automatic Balanced Fill-Flash changed all that.

Today, it is offered in all of Nikon's Autofocus SLR models, and the use of
fill-flash has expanded from being a highly limited feature to one that
is routinely used to enhance picture taking. The effective results from
Nikon's Matrix Automatic Balanced Fill-Flash system have been
extensively demonstrated, and the system is widely used among amateurs
and professionals. The results are especially evident in photos taken
with camera models such as Nikon's F4S and N8008S when used with Nikon's
popular SB-24 AF Speedlight and AF Nikkor lenses.  Nikon's N6006 and
N5005, with both their built-in speedlight and external compatible Nikon
TTL speedlights also employ Balanced Fill-Flash capability.

Nikon has now expanded the technique. The N90 uses the power of new
computers, exclusive Nikon software and a new 5-segment flash meter so
that automatic fill-flash photography can enhance more pictures than
ever before.

            Highlights of Nikon's New Flash Technology

Various new technological features are employed in the new Nikon N90
system. Here's a run-down on each feature and the role it plays in
performance.

8-segment Matrix Meter for ambient light exposure control: Feeding data
about scene brightness and contrast patterns to the camera's computer,
the new Nikon N90 8-segment Matrix Meter features an additional, finely
patterned 3-segment centered element to compliment the overall 5-segment
pattern. The 8-segment sensor's eetection is controlled by the
computer, which selectively analyzes the limitless range of light
patterns that appear.

D-type AF Nikkor lenses:  All AF Nikkor lenses work effectively with the
new Nikon N90's 8-segment light meter and 5-segment TTL flash system.
The newest AF kkkkor D-type lenses, in addition to all of the features
of an AF Nikkor, also incorporate a "Distance encoder."  After
auto-focusing is accomplished, the D-Type ssss signals the actual
camera-to-subject distance to the camera's computer. This distance
information can be used by the computer to provide the most advanced
exposure control for both ambient and flash illumination.

5-segment TTL flash sensor for flash detection:  The 5-segment TTL flash
sensor significantly distinguishes the  Nikon N90 from all other
systems. Combined with all of the system's new technology, this
multi-segment sensor brings never-before-available Matrix-like exposure
analysis to TTL flash control.

One-segment TTL flash sensor control which is not effectively integrated
with the camera's ambient light meter exposure control operate under
serious limitations. For example, they can not determine the location
of the main subject, nor can they estimate subject reflectance. They
are easily fooled by a very bright or rrrk object within the scene, and
by subjects in the foreground that reflect too ccch flash illumination.
They are also unable to integrate ambient light exposure control with
the flash exposure control, resulting in overly dark or light
backgrounds and an artificial looking picture.

Nikon's original Automatic Balanced Fill-Flash, which is integrated with
the camera's Matrix light meter, is able to effectively address some of
these conditions, but the newest version -- the 3D Matrix Automatic
Balanced Fill-Flash system, using a 5-segment TTL flash sensor -- excels.

Nikon SB-25 AF Speedlight with Monitor Pre-Flash:  Under conditions when
flash is most used -- EV13 and darker -- operating in the TTL
mode, the Nikon SB-25 AF Speedlight activates its Monitor Pre-flash each
time a flash picture is made. During the moment after the mirror is
raised but before the first shutter curtain begins to move, the flash
fires a pre-flash of imperceptible light.

Depending on conditions, the pre-flash may fire up to 16 times. The
Pre-flash light reflects from the scene and is detected by the camera's
5-segment TTL flash sensor. This information is analyzed and the
results are used to control which TTL flash sensor segment or segments
will be used for the final flash sensing and what level of biasing
(weighting) will be employed for each sensor's reading. The resulting
information is also analyzed in connection with distance information
(from an AF Nikkor D-type lens) and defocus information (from all AF
Nikkor lenses) for further refined exposure control.

5-segment weighting:  Similar to Matrix metering for ambient
illumination, the 5-segment TTL flash sensor detects the brightness from
the reflected pre-flash light. This aids the system in analysis of not
only the scene's component reflections, but also its composition. The
flash analysis is compared to the 8-segment Matrix meter's reading for
ambient light.

Brightness Value and Distance Analysis:  Exposure failure resulting from
a subject that is significantly higher or lower in reflectance than
standard reflectance is a common cause of bad exposures -- very light
subjects tend to be underexposed and very dark subjects overexposed,
becoming a shade of gray instead of their natural black or white. The
N90's Brightness Value and distance analysis mark the first time that an
ambient / flash exposure detection system can perform a calculation that
helps overcome this problem.

Using any AF Nikkor lens, this calculation helps achieve the final
exposure control. With D-type AF Nikkor lenses, the control is
enhanced.

Guide Number Analysis:  Among the many calculations performed by the
camera's computer is a Guide Number analysis. Each of the five
reflected brightness value readings is analyzed using the guide number
for the Pre-flash and comparing it with the lens aperture. Using the
formula, Distance = Guide Number / f-stop, the computer will analyze the
Brightness Value from each sensor reading. This calculation is analyzed
together with the original focusing distance information and the defocus
status information.

Using the N90 with a D-type AF Nikkor lens and the SB-25 AF Speedlight,
here's an example of how it works when a subject is centered in the
finder:

1. The D-Type AF Nikkor lens and the camera's CAM246 focus detection system
   provides the camera-to-subject distance and defocus status. For this
   example, becaue the subject is in the center of the finder, the defocus
   status amount will be small and signal the camera that the focused subject
   is probably in the center of the finder.

2. The 8-Segment Matrix Meter provides the ambient light's brightness and
   contrast analysis and final ambient light exposure control.

3. The SB-25's Monitor Pre-flash fires. At this point, the camera's
   computer will have the following information:

   o  ISO of film in use
   o  Monitor Pre-flash guide number
   o  Subject distance
   o  Lens aperture in use
   o  Brightness value (from pre-flash) for centered subject

Using all of the known information, the computer compares the Brightness
value from the subject to a theoretically calculated Brightness value
for a subject of standard reflectance. Based on this calculation, the
exposure control can be biased (weighted), adjusting flash control for
the actual subject reflectance. Through this technique, blacks and
whites will be accurately rendered in their natural tone, and not in a
shade of gray.

Defocus detection from the Electronic Rangefinder:  Different from
distance, "defocus" is a term that indicates the extent by which the
subject is not in focus. When defocus is large, the subject is extremely
out of focus. As defocus diminishes to a smaller amount, the subject
becomes in-focus. Electronic Rangefinder and Autofocus operation is
based on a measurement of defocus amount, not on the distance to which
the lens is actually focused.

Defocus and Composition Analysis:  If after focusing, the photographer
decides to lock in focus and change composition, the N90 can take that
into account. It uses its memorized data of defocus amount in the
central area of the viewing system, and the distance to which the lens
is focused. In addition, the N90's exposure control system memorizes
the ambient light pattern from the original composition and then
analyzes the new composition's light pattern, comparing it to the
original.

After the photographer locks focus and recomposes, the camera's
Electronic Rangefinder (using defocus status) will detect if the center
of the newly composed scene is at the same or at a different distance
than that of the original composition. If it is different, that
information is analyzed by the computer and factored into the overall
exposure calculation for ambient light exposure control.

Next, as the photographer completes pressing the shutter button to make
the exposure, the Pre-flash fires. The computer then compares the
brightness values  of the Pre-flash light reflected from the scene with
the multi-segment ambient light exposure reading of the original
composition and with the original distance information for the center
segment. If the brightness value of the center segment is now too high,
the camera knows the new center composition is closer than the original
composition; if it is too low, the new center composition is farther
than the original composition. In either case, the computer will use
this information to adjust exposure control for the flash.

Real-Time TTL Flash Control:  Following the exposure control analysis
sequence, the system controls the amount of light put out by the flash
during the actual exposure and produces the final result - a 3D
Matrix Automatic Balanced Fill-Flash picture.

Fast, accurate and responsive:  This enormous number of calculations,
all performed by the N90's high-power computer using Nikon's exclusive
Fuzzy Logic Software, takes place during the mere milliseconds available
between the moment the shutter release is depressed up to the final
closing of the shutter curtains.

A Practical Example of a 3D Matrix Balanced Fill Flash In Action with an
Off-Center Subject:

The "D" stands for "distance", and it represents a whole new dimension
in automatic exposure analysis and flash control. When the photographer
puts the camera up to his eye and touches the shutter release button,
the first thing that happens is that the matrix meter analyzes the light
pattern and the lens focuses. The distance signal from the D-type AF
Nikkor lens is entered into the computer along with the Matrix analysis
and the first set of information is now in the N90's computer. This
happens in just a few thousands of a second.

If the photographer then locks in the focus and recomposes for an off
center subject, the N90 next detects the new light pattern and it
determines that the photographer is no longer pointing the camera at the
same subject. How? Because, while the lens remains focused to the
original distance, the Electronic Rangefinder detects that there is a
greater amount of defocus in the center of the scene.

When the photographer fully depresses the shutter release button, the
mirror swings up, the ambient exposure information is locked in, and the
five-segment flash meter goes into action, analyzing the Monitor
Pre-flash pulses of light, which are invisible because they fire so
fast. As the light pulses, each of the five sensors detects the
reflection of the Monitor Pre-flash and the computer performs an
analysis of the brightness value that has been reflected back from
the subject to the meter.

This is where it gets its Matrix-like information. The system detects
five different brightness values. The camera has the lens aperture and
the brightness value of the light coming back. It also has the guide
number of the Monitor Pre-Flash. Using the formula f/stop equals guide
number divided by distance (f/stop = GN/D), the camera can actually
calculate the distance of the subject from which the light was reflected
and estimate which sensor is detecting light from the originally focused
subject.

Through its computer analysis, the camera then decides how to weight the
sensitivity of the selection of sensors that it will finally use for the
detection of the full powered flash as it fires.

Finally the flash fires, and based on that analysis, the output of the
flash is controlled. The entire process takes only milliseconds, so
fast it seems to be virtually instantaneous. The end result is a 3D
multi-sensor automatic balanced fill flash.

Handling High-Contrast, Centrally-Located Subject:  Consider the problem
encountered when you try to photograph a centrally-located subject
against a very high contrast background -- the face of a model or a bride
swathed in white, a scene containing car headlights, or a mirror or some
bright light in the surrounding area. It could also be the opposite, a
face surrounded by a dark background. The typical automatic flash
system will tend to underexpose when there is a bright light in the
background, and over expose when there is a dark background. The N90's
remarkable system estimates what brightness value the subject should
have and compensates accordingly. No other can camera operates in this
way.

The Nikon N90 knows the distance of the subject because it received that
information from the distance encoder in the D-type AF lens. When the
light reflected off a centrally located subject comes back to the camera
sensor using its guide number calculation, it then calculates whether
or not the subject is of a standard reflectance.

The camera can then compares that information with the brightness values
detected by the peripheral sensors, which may be reading excessive background
brightness or darkness, and then determine whether the exposure should
be based primarily upon the center segment.

For the first time, there is a system that is not only capable of
measuring the light coming back from a centrally-located subject during
a flash exposure, but is additionally capable of estimating if that light
is of a standard reflectance or some other value.

The N90 can instantly handle photo situations that take time and effort
to set up and may be technically beyond the knowledge of many photographers.

             The Nikon Perspective on System Integrity

System integrity and non-obsolescence have always been hallmarks of the
Nikon system. Now with the introduction of the N90 SLR, the concept has
been expanded. Nikon System integrity has always dealt with maintaining
the compatibility of lenses and accessories, and the N90 offers that, and
much more. With the N90, Nikon brings a new technology to photography.
The 5-segment sensor TTL flash control system integrated with the
multi-segment ambient meter, along with powerful new built-in computers and
Nikon software for exposure analysis, is unprecedented.

Equipment Selection
-------------------
Total N90 system capability for flash control depends on the selection of lens
and Speedlight and on whether the Multi-Control back or Data Link remote
system is used.

For 3D Multi-Sensor Balanced Fill-Flash use the Matrix meter,a D-type
lens, and an SB-25 AF Speedlight.

With a non-D-type AF Nikkor or AI-P lens and any TTL Speedlight, the
distance analysis and Monitor Pre-flash are not available. Enhanced
performance is available through the use of the Matrix Meter and
5-segment TTL flash sensor.

With AI-S Nikkor Lenses, the N90 provides Center-Weighted and Spot
metered Balanced Fill-Flash.

Manual flash compensation control is possible with the N90 and can be
used with any compatible TTL Speedlight as an additional creative
alternative.

Automatic flash sequence exposure bracketing is possible with the N90
when using the MF-26 Multi-Control Back or the Nikon Data Link system.

With autofocus-capable speedlights such as the Nikon SB-25, SB-24,
SB-23, SB-22 or SB-20, the Nikon N90 can even focus automatically in
total darkness using the focus assist light included in each of these
Nikon Speedlights.

Flash Sync Options for the Nikon N90 include three built-in flash
synchronization settings with most Nikon Speedlights: Normal Sync, Slow
Sync and Rear Curtain Sync. In addition, Focal Plane High-Speed Sync is
available with the new Nikon SB-25 Speedlight.

Slow Sync: When using the Slow Sync setting for flash photography, the
Nikon N90's shutter operates over the entire synchronized slow speed
range, from 1/125 to 30 sec., which allows the photographer to
automatically combine long available-light exposures with a flash
exposure.

Using Shutter-Priority Auto or Manual exposure mode, the shutter fires
at the user selected speed, and if set at a speed faster than 1/250
sec., the shutter is automatically reset to 1/250 sec. to ensure proper
synchronization.

Rear Curtain Sync: Rear Curtain flash synchronization control is also built
into the Nikon N90 and can be used with all compatible Nikon TTL
speedlights. With this mode, the flash is triggered at the end of the
exposure. The results from this feature become most evident when using
slow shutter speeds.

For example, if the subject is a model carrying a colored light in a darkened
studio, a slow sync ambient-light exposure followed at the end by an
action-stopping flash can capture this light as a blur streaming out behind 
the
flash-exposed subject. Using ordinary manual controls, photos of this
type are technically complex, and very difficult if not impossible to
accomplish. The Nikon N90 with its Balanced Fill-Flash systems, Slow
Sync and Rear Curtain control makes it fast and precise.

FP Sync:  Focal Plane (FP) sync performance is available exclusively with the
Nikon SB-25 AF Speedlight. It offers new picture opportunities for serious
action flash photography.

Normally, electronic flash is limited to exposure speeds that allow the focal
plane shutter to open fully during exposure. At higher speeds, the shutter
becomes a traveling slit and a single high-speed burst of electronic
flash, which lasts only milliseconds can expose only part of the frame,
leaving blank the part not oovered by the open slit.

Nikon's new Focal Plane sync technology, built into the SB-25 and
operable with the N90, conquers this barrier by emitting a very rapid
series of pulsed flashes that maintain illumination throughout the
duration of the focal plane shutter's travel across the film. Although
pulsed, it happens so rapidly that the light does not have an
opportunity to fall off appreciably, and the net effect is that of a
continuous light.

Operation is exclusively for manual exposure and only at speeds from 1/250 to
1/4,000 sec. Higher speeds do not allow for a sufficient number of
pulses and lower speeds require more time than the flash can sustain.
Two power settings are provided for maximum flexibility at different
film speeds and in different situations.

Using this mode, the guide number of the flash varies with the shutter
speed in use. For example, with a subject at 10 feet and ISO 100 film,
the Guide Number is GN40 (GN12 metric) at 1/500 sec., and GN14
(GN4.3 metric) at 1/4,000 sec.

FP sync shatters the traditional limits for flash sync with substantial
flash power for a focal-plane shutter. It permits fill flash even in
bright sunlight sunlight with today's high-speed films and has applications
across a broad spectrum of photo situations from wedding candids to news,
nature and sports.

Other N90 Flash Features with the SB-25:  In addition to Monitor
Pre-flash and FP sync, other features available with the SB-25
Speedlight include red-eye reduction, manual variable power to 1/64,
rapid firing strobo type flash at up to 50 Hz, non-TTL A mode, TTL mode,
Zoom-rotating bounce head, automatic zoom coverage from 85mm to 20mm
focal lengths, and a built-in bounce card.

Red-eye reduction: is available exclusively with the new SB-25 AF
Speedlight used on the Nikon N90. Using a three-pre-flash system, which
is different from high-speed Monitor Pre-Flash, the subject's eye-pupils
close, and as result annoying red-eye is reduced. This feature can help
improve the quality of portraits.

Flash Attachment:  A variety of flash attachment systems for use with
single and multiple flash units are available for the N90.

The N90 has an ISO type hot shoe with contacts for the ready light,
TTL flash and monitor. The mount also has a receptacle for the SB-25
Speedlight's Posi-Mount System, which prevents the flash from
accidentally coming loose from the camera.

The N90 also incorporates a standard PC-type threaded flash terminal for
compatibility with standard non-TTL cord-type speedlights, including studio
speedlight systems.

Control of from one to five off-camera Speedlights is possible using the
Nikon SC-17, SC-18 and SC-19 connecting cords.

Recognizing the Difference
--------------------------

Where Nikon's new integrated multi-segment ambient/multi-segment flash
metering system stands out is with photographic situations that are not
average.

For an average scene, the results may be outstanding, while the results
from other less sophisticated camera systems may only be acceptable. On
the other hand, when a photographer tries making a picture of a
high-contrast subject moving through rapidly changing light and distance,
the new system in the Nikon N90 can make the difference

--
Eric R. Feigenson			UUCP: {mit-eddie,linus}!progress!erf
Progress Software Corp.		    Internet: erf@progress.com
14 Oak Park			  DISCLAIMER: I don't speak for my employer,
Bedford, MA  01730		              and vice versa.