STEREOSCOPIC CAMERAS 15The lenses are of only 25mm focal length, a fact which makes
it possible to dispense with focusing adjustment. Satisfactorily
sharp pictures at a distance of 28 inches have been made, indi-
cating the entire practicality of the fixed-focus lens when the
focus is so short. The lenses have a maximum aperture of f3.5
and are coated.
The shutter is of the time proven guillotine type which cannot
possibly get out of synchronization and is speeded 1/10 to 1/100
with Bulb. A flash synchronizer for five millisecond delay (SF/SM
bulbs and most portable strobe units) is built in and couples for
all speeds.
The picture size is i2xi3mm upon a 12xi8mrn film. The extra
6mm in length provides a tab which is indexed in the camera
to indicate right or left and also forms a “handle” so that the
film surface never need be to_uched in mounting. A 20-exposure
magazine of standard 35mm film provides 38 stereo pairs. The
method of adapting the so-called 16mm size to the 35mm film
is unique. During the first ig exposures, the lenses are opposite
the top half of the film and the exposures extend to the midline
of the film. When ig exposures have been made, a dial on the
front of the camera is turned. Then the lenses are opposite the
lower side of the film, the film travel is reversed and ig more
exposures are made along the bottom of the film. When the last
exposure has been madd the film is already rewound ready to be
removed from the camera.
The release is located at the lower, right corner of the camera
(in operating position), and is pressed back into the camera.
This provides a natural squeeze motion which is unlikely to
produce camera bounce.
To make mounting easy, a special film punch is provided
which punches out both films simultaneously, thus providing
mechanically positive alignment between the two films. The
camera apertures have small notches in one edge. One is semi-
circular, the other square. These are the right-and-left indi-
cators. The blank reels have 14 pockets. One is numbered 1, with
a semi-circle, the opposite one is numbered 1 with a square mark,
and so on for seven pairs. You do not even need to know which
is right or left. You simply take the punched film which has the
circular mark and place it in the pocket bearing the same mark.