An Improvement in Cameras for Colour Photography.
Year: 1899

page_text: I, ARTHUR JOHN OSBORNE POLLOCK, Colonel, Newcastle House, Kingscourt,
Ireland, do hereby declare the nature of this invention to be as follows:-
This invention relates to cameras for use when taking coloured photographs.
The invention consists in using three lenses in the camera two lenses being
arranged one beside the other and the third above and intermediate of the other
two. By having this arrangement the operator is enabled to take three nega-
tives (red, blue and green) of an object by direct rays instead of by means of
reflectors as hitherto practised. Each lens box may be fitted in a chamber
which is cut off from its neighbours by means of divisions which are removable
so that when desired the lens boxes can be removed the divisions withdrawn
and a single lens substituted in order to do ordinary photographic work.
By this invention practically three cameras are in use within a single casing
so that three negatives can be taken at a time.
Focusing is not necessary with this invention.
Of course the three lenses, instead of being arranged as at first herein before
described, can be arranged in any other suitable manner.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.
An Improvement in Cameras for Colour Photography.
I, ARTHUR JOHN OSBORNE POLLOCK, Colonel of Her Majesty's Forces, New-
castle House, Kingscourt, Ireland, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement: —
This invention relates to cameras for colour photography.
With my improved camera three simultaneous exposures for colour photo-
graphy can be made without the intervention of a reflector, and, further, when
so desired the camera can be adapted for use as an ordinary camera.
In order that the invention may be properly understood I have hereunto
appended an explanatory sheet of drawings, whereon,
Fig. 1 is a front view of the camera.
Fig. 2 is a back view of the camera with the focussing screen removed.
Fig. 3 is a cross section of the camera taken on the line A-B Figs. 1 and 2.

page_text: Fig. 4 is a view of the removable inner body for use when taking coloured
photographs.
Fig. 5 is a plan of the inner body.
Fig. 6 shows the caps for the lenses.
As will be seen from the drawings the instrument consists of a rectangular
body a with a removable inner body b which fits into place with a sliding fit.
care guides for the inner body and c is a guide frame at the back of the main
body a. d is the usual ground glass focussing screen it is only shown at Fig. 3.
e, el, e, are three lenses arranged at the front of the camera, the lenses e¹ and e²
being arranged one beside the other and the lens e above and intermediate of
the other two.
The inner body is divided into three boxes or chambers f, f, f, divided off
from one another by means of division pieces g, g¹. It will be seen that the
arrangement of the chambers corresponds to the arrangement of the lenses,
that is to say, the chamber f is above and intermediate of the other cham-
bers f¹, f. At the front end of each chamber is a colour screen and these
colour screens are fitted removably in place, the colour screen h for the upper
chamber being passed through a slot at the upper side of the chamber and
held in place by means of a button i whilst the colour screens and 12 for the
chambers and fare passed through a slot at the side of each chamber and
are held in place in a similar manner to the screen h. The screens consist of
coloured glass, the screen h being red. the screen 1 blue and the screen ² green.
It will be seen from Figs. 1 and 2 that there is a lens to represent each screen.
The three chambers practically constitute three cameras so that three nega-
tives can be taken at once.
The principle of the camera is that the positives from the three negatives
are viewed through three colour screens, one positive must superimpose with
the other two; the process is known and has already been patented by a Mr. Ives.
What is claimed for this camera is that in colour photography three exposures
can be made at the one time without the intervention of a reflector as has
hitherto been practised and also that the camera can be used either for colour
photography or ordinary photography as desired.
The front board a¹ (see Fig. 3) of the camera is removably fitted in place in
the usual manner with cameras having movable front boards so that when it is
desired to use the camera for ordinary photography the front board with
the three lenses thereon can be removed and replaced by a front board with a
single lens thereon. The inner body is, in such cases, also removed so that the
camera can be used in the same manner as an ordinary camera.
Owing to the law of parallex the camera with its three lenses is always in
focus that is to say no focussing is required as the camera can only be used
for objects situated beyond a definite point the point varying with the focal
length of the lenses used.
The three simultaneous exposures are made by means of three caps 1,1‚ Î²,
for the lenses. The caps are connected together by radial bars which are con-
nected together at the centre and provided at this point with a knob or handle k¹.
If so desired a shutter may be used instead of the caps.
The necessary difference in the duration of the exposure for each of the
colours is regulated by the size of the aperture of each lens. For example
the red screen negative requires the longest exposure and therefore its lens has
the largest aperture, the blue screen negative requires the least exposure and
therefore its lens has the smallest aperture, whilst the green screen negative
requires an aperture between that of the red and the blue and therefore, for
its lens, an aperture of intermediate size is used.
If desired, as an alternative arrangement for giving the varving exposures
three shutters, released at one movement, may be used each shutter giving a
different exposure: or a shutter arrangent may be used in conjunction with
the aperture method above described.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I consider novel and desire to claim is:-
1. A camera for colour photography capable of making three simultaneous
exposures without the intervention of a reflector, substantially as herein before
set forth.
2. A camera made substantially as herein before described and which can be
used as desired either for colour photography or for ordinary photography.
Dated this 27th day of November 1899.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.