Page 36 - RD_2024-06

In consequence, twice
the footage is used for a
given scene. Through
colour filters placed in
front of the upper and
lower frames of the film,
which is colour sensitive
(panchromatic), one
section registers only
the reddish or ‘warm’
colours, and the other
the greenish or ‘cold’
colours.

"The film, when
developed, resembles a
normal black and white
negative, except that
each alternate exposure
includes only the red or
the green. Two separate
positive films are
printed, which are to
serve as ‘block?’ in the
printing of the final film. One of these two positives forms a continuous strip of only the red
frames of the negative: the other of only the green.

"The two positive films are chemically treated, so that the dark portions of the image are caused
to swell out from the surface of the film. The uneven surfaces thus created later act in the printing
process like the raised letters on a rubber stamp. A dye of suitable reddish shade is applied to the
positive of the red parts of the picture prepared in this way, and by mechanical contact the red
portions of the scene are transferred to a blank film. The green parts of the scene are printed from
the other positive film directly over the red impression. The resulting film in full colour can be
run through any projection machine in the ordinary manner.”
As for Grandeur and Spoor-Bergren films, the pictures are taken and projected with more highly
corrected lenses capable of giving sharp detail to the edges of a wider field. The chief technical
difficulty lies in running the 70 or 65 millimetre film through the camera and later through the
projector, and keeping it from buckling and causing areas of the picture to appear out of focus.
This, technicians say, has been overcome by a special mechanism which practically “floats" the
film through camera and projector on a "cushion of air.” Details of the method, however, are still
being kept strictly secret.
To obviate the buckling obstacle, Leon F. Douglass, a Californian experimenter. has devised a
panoramic lens which permits pictures for projection on the new wide screens to be taken upon
film of standard width. Another advantage of this invention is, of course, that it would save the
added expense of the double film. Working on the same principle as the distorting mirrors seen
at amusement places, it condenses a double-width picture into a single width of film. An
adjusting lens in the projection machine restores the picture to its normal proportions.

36 REEL DEALS March 2024