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When we have the three different negatives colour record as 
explained, the same are then printed in the colours indicated 
above, and each colour is printed in succession on the other, so 
that a complete print is only formed when holding a blue, a 
yellow and a redimpression. The name applied to such a print is 
three-colour print. 
The ordinary way to produce the three necessary negative 
colour records is with a camera having a repeating back or by 
change of slides. That is by three different and distinct 
exposures, thereby limiting the subjects to be photographed in 
colours to absolute stationary objects. 
Ditferent attempts have been made to take the three negatives 
with one exposure, and for that purpose the chromoscope has 
been tried, but found wanting, because three negatives of same 
size could not be obtained therewith. A chromoscope as generally 
known has not less than two reflecting surfaces ; but there is a 
reflecting system with only one mirror, known as Bennetto’s 
system. I have tried to use this system, but found that the 
refracted image was shorter from top to bottom when compared 
with the reflected image. Now if one glass reflector, like in 
Bennetto’s camera, interferes with the size of the picture, it should 
become obvious that double this interference will not improve a 
chromoscope camera with two glass reflectors. I have succeeded 
in correcting this interference, which is caused by the difference 
of a longer refraction at the top of the glass reflector to a shorter 
refraction at the bottom of the same glass reflector, which latter 
is inclined at an angle to a light cone coming from the optical 
centre of the lens. The correction consists of a plain glass plate 
of same substance as the reflector, and by inserting same at a like 
angle as the reflector, but in opposed direction ; that is, if the . 
reflector acts from top to bottom, the compensation acts from one 
side to the other side. By forcing each light ray to pass the two 
refractions as indicated the negative at the back is foreshortened 
in all directions alike if left in the old focussing plane, but by 
placing the plate a little further away in the proper, through 
refraction displaced, focussing distance, it will be found that this 
double refracted picture will be sharp, of equal and correct size, 
when superposed on the reflected image. The patent 25907, 
zg06, embodies the necessary improvements to take the three 
negatives of same size, with one single exposure and with one lens. 
To take three negatives with this camera: One is taken at 
the back, the blue record through the red reflector. The second 
negative is taken by way of reflection from the red reflector 
through its own glass surface at the top, therefore being 
not reversed. The third negative is on a flexible plate and is 
obtained on a ortho-chromatic plate pressed film to film, 
with the second plate which acts as yellow filter. By printing 
