Year: 1897

page_text: T. EDWIN TRANTER BUTLER, Broomlea, Cambuslang, Glasgow, Steel Plate
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention relates to a single, or sterescopic, colour camera for the purpose
of taking three separate negatives simultaneously at one exposure by means of
the same lens.
It consists of a sliding body camera fitted with single or stereoscopic lenses
which may be adjustable and two coloured glass reflectors set at an angle of
forty five degrees with the base of the camera and may have three coloured
screens to act as ray filters.
The first reflector is greenish blue, the complementary colour to red.
The second reflector is yellow, the complementary colour to violet.
The image proceeding from the red rays of the subject to be photographed
is reflected upwards by the first reflector and is focussed on a sensitive plate placed
horizontally fixed in a dark slide which produces negative No. 1. A red plate of
glass may be placed beneath the sensitive plate which causes the red part of
picture to be more intense, although the action is quicker without the red plate.
The image proceeding from violet rays of object to be photographed is trans-
mitted by the first reflector and is reflected upwards by the second reflector and
focussed on a second sensitive plate placed horizontally in a dark slide which
produces negative No. 2. A violet blue glass is placed beneath the No. 2 sensi-
tive plate which causes the violet blue part of picture to be more intense.
The image proceeding from green rays of object to be photographed is trans-
mitted by both the first and the second reflectors and is focussed on a third sensi-
tive plate placed perpendicularly also in a dark slide which produces negative
No. 3. A green glass may be placed before No. 3 sensitive plate which causes the
green part of the picture to be more intense.
All the negatives are taken simultaneously at one exposure and by one lens if
the camera be single and a pair of lenses if stereoscopic which ensures the views
on each being the same, excepting as regards density which differs on each plate
according to the strength of colour represented.
Transparencies taken from these negatives in the ordinary way may be used in
the Kromskop or for other purposes.
A diaphragm is placed before each reflector to exclude all surface reflection
from the lens and prevent fogging of the plates.
When the camera is stereoscopic a partition between the lenses and through
the camera separates one stereoscopic side from the other.
The camera is lined with black velveteen this being a more perfect absorber of
light than the ordinary lamp black and so assists in the very important object of
keeping all diffused and reflected light from the sensitive plates except the direct
light of the image.
One advantage of photographing the subject on three separate plates is that
different kinds of sensitive plates may be used under the same exposure for the

page_text: different colours thus for the red an orthochromatic plate which is more sensitive
to the red rays is used and for the blue and green images separate plates may be
used which are more sensitive to those colours.
Having described the purpose of the camera and the manner of its use I would
sum up the essential features of my invention as being as follows:-
1. A single or stereoscopic colour camera having a simple device consisting of
two transparent coloured reflectors and three supplementary coloured screens.
The colours of the said transparent reflectors being analogous or secondary to one
primary colour and complementary to the other two, for separating the primary
colours of light, and arrangement for focussing the images from the same on
three separate sensitive plates two of which are placed horizontally and one per-
pendicularly each in a separate dark slide and so allowing the use of different kinds
of sensitive plates each of which may be particularly sensitive to the colour it
represents and thus shortening the exposure.
2. The reflectors used being only two, no opaque reflectors or mirrors and no
object lenses, there is less absorbtion of light which also shortens exposure.
3. The arrangements for focussing and the internal arrangements of diaphragms
and light absorbing lining and arrangements for dark slides renders this instru-
ment specially suitable for taking three colour negatives but unsuitable for
viewing the pictures.
"
The invention also comprises a supplementary addition to the "Kromskop
which may be used in connection with that instrument, after removing its internal
arrangements of reflectors and the lenses, for the purpose of enabling anyone
possessing a Kromskop to use the combined arrangement for taking three colour
negatives from which transparencies may be taken and shewn in the ordinary
Kromskop.
It consists of a covering box with removable lid of a suitable size to hold the
Kromskop and space to slide backwards and forwards for focussing purposes and
space to hold extension body fitted with shutter to keep out the light while the
shutters of the three dark slides in connection are being withdrawn. The front
of the box is fitted with adjustable lens with shutter arrangement which keeps
out the light while the interior shutter attached to the extension body is being
raised thus enabling three double dark slides to be changed in daylight to secure
two sets of negatives.
And also a frame to slide into the Kromskop consisting of transparent reflectors
fitted with diaphragms and central partition.
The combined arrangement constituting a photographic camera for taking three
colour negatives and in such a manner that suitable sensitive plates may be
used in each dark slide to facilitate the shortening of exposures.
The Kromskop not being a fixed arrangement but removable is not precluded
from use for its own purpose of viewing after attaching its own lenses and
interior arrangements.
The arrangement for moving the Kromskop within the box when required for
focussing or the movement of the lenses by rack and pinion, may indicate on a
marked the distance in yards at which the subject is in focus.
Dated this 10th day of December 1897.

page_text: same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention relates to a single or stereoscopic colour camera for the purpose
of taking either one, two or three separate negatives, and in either of the latter
cases taking them simultaneously and at one exposure by means of the same lens
or pair of lenses.
It consists of a camera fitted with single or stereoscopic lenses which may be
adjustable and having either one or two coloured glass reflectors set at an angle
of forty five degrees with the base of the camera and two or three coloured screens
to act as ray filters.
The reflectors are of a colour complementary to the colour desired to be reflected.
The first reflector may be greenish blue the complementary colour to red. The
second reflector may be yellow the complementary colour to violet.
The image proceeding from the red rays of the subject to be photographed is
reflected upwards by the first reflector and is focussed on a sensitive plate placed
horizontally fixed in a dark slide, which produces negative No. 1.
A red plate
of glass may be placed beneath the sensitive plate which causes the red parts of
picture to be more intense.
The image proceeding from violet rays of object to be photographed is trans-
mitted by the first reflector and is reflected upwards by the second reflector and
focussed on a second sensitive plate placed horizontally in a dark slide, which
produces negative No. 2.
A violet blue glass is placed beneath the No. 2 sensitive plate which causes
the violet parts of picture to be more intense.
The image proceeding from green rays of the object to be photographed is
transmitted by both the finst and the second reflectors and is focussed on a third
sensitive plate also in a dark slide placed perpendicularly, which produces nega-
tive No. 3.
A green glass may be placed before No. 3 sensitive plate which causes the
green parts of the picture to be more intense, by its absorbtion of other rays.
All the negatives are taken simultaneously at one exposure and by one lens if
the camera be single and a pair of lenses if stereoscopic which ensures the views
on each being the sanre, excepting as regards density which differs on each plate
according to the strength of colour represented.
But in order that my said invention may be more readily understood and easily
carried into effect I will proceed to describe the same with reference to the accom-
panying drawings in which
Fig. 1 is a sectional side elevation
Fig. 2 a sectional plan and
Fig. 3 a front view, also partly in section, of a stereoscopic camera constructed
to take three negatives simultaneously at one exposure.
Fig. 4 is a sectional side elevation and
Fig. 5 a plan, also partly in section. of a stereoscopic camera constructed to
take two negatives simultaneously.
Referring to Figs. 1. 2 and 3 of the drawings I construct the camera of wood
or other suitable material, preferably lined with black velveteen. having two
dark slides A & B arranged horizontally above and a third dark slide C arranged
vertically at the back of the camera. The dark slide A is carried in a box
portion D which is connected to the body of the camera by spring clips so that
it can be readily removed for the purpose of gaining access to the inside of the
camera when desired.
Below the dark slide A, in the position shewn, is situated the greenish blue
reflector E for reflecting the red rays, proceeding from the subject being photo-
graphed, on to the plate in the dark slide. e is the red plate of glass for inten-
sifving the red parts of the picture.
Fis the vellow reflector for reflecting the violet rays, transmitted by the

page_text: reflector E, upwards onto the plate in the dark slide B. f is the violet blue
glass which causes the violet blue parts of the picture to be more intense.
Gis the green glass which intensifies, by its absorbtion of other rays, the green
parts of the picture transmitted by the reflectors E & F on to the plate in the dark
Slide C.
In the example the camera is shewn fitted with a pair of single lenses H mounted
in a sliding body h actuated, for focussing purposes, by a rack and pinion as shewn
The front of this sliding body is fitted with a cap J and also with a double screen j
having suitably coloured glasses j¹ as and for the same purposes as those used
with ordinary cameras.
Partitions K are arranged between the lenses and through the camera so as to
separate one stereoscopic side from the other and a diaphragm k is placed before
each reflector to exclude all surface reflection from the lenses and thus prevent
fogging of the plates.
Different kinds of sensitive plates may be used under the same exposure for
the different colours, thus an orthochromatic plate, which is more sensitive to
the red, may be used in the dark slide A.
Transparencies taken in the ordinary way from the negatives thus obtained
may be used in the "Kromskop" or for other purposes.
When only two negatives are desired to be taken simultaneously, only one
reflector need be used of a colour complementary to the colour represented by
one negative and analogous to the colour represented by the other. Such a camera
is shewn in Figs. 4 & 5, the reflector L being mounted so that it can be removed
and another substituted as desired in place of being permanently secured as in
the first described example. With this form also I may employ a pair of lenses
each of which can be focussed by hand. independently of each other, the said
lenses being enclosed by a light tight box L¹ hinged at 1 and secured by a
spring catch, or otherwise removably connected. The front of this box is fitted
with a cap M and may or may not be provided with a coloured screen.
Also any
ordinary means may be used for interposing a coloured screen before the lens or
lenses when desired.
Although the examples described are stereoscopic the same relative positions
may be occupied by the various parts when it is desired to take two or three
single negatives simultaneously, in this case however one lens only being
employed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
clair is.-
1. A single or stereoscopic colour camera having transparent coloured reflectors
and supplementary coloured screens for absorbing or separating the constitutent
colours of light, substantially as hereinbefore described and shewn in the accom-
panying drawings.
2. In a single or stereoscopic colour camera, the arrangement of the dark slides
and the method of focussing the images transmitted and reflected by the coloured
reflection and screens, upon the plates contained therein, whereby different kinds
of sensitive plates may be emploved to suit each colour of the picture to be photo-
graphed, substantially as herein before described and shewn in the accompanying
drawings.
Dotad this Oth dor of Santambor 1808