allow adjustment of "coincidence" which is independent of the focus setting.
Proper geometry is adhered to while allowing a
true (x, y, and z) scaling of 3.75 times normal.
The overall dimensions of the camera are:
3"(8cm) wide x 2"(5cm) tall x 5"(13cm) long
with a 0.7"(17mm) spacing of the lenses.