Firm fixing and adjustment is provided for 
b
the use of plastic "pin-bars" which fit nicely into the top and
bottom recessed rails. The film chips fit over accurate
"pins" on the pin-bars. There are marks on one side of the
pin-bars which permit them to be placed as illustrated to achieve a
vertical variation of from zero (1) to 0.4mm (5) in 0.1mm increments.
(There are alternative pin bars available that allow adjustments in
approximately 0.2mm increments to 0.7mm).
Accurate baseline or vertical registration is achieved by working to a
proven jig / grid mounting system or by trial and error, checking progress
in your stereoscope (viewer). Freeviewing can also confirm baseline
accuracy, particularly if enlarging lenses are used. The most useful
non-projection jigs have a light-box under and a pair of lenses
over.
When it comes to adjusting for horizontal position, move the chips on
their pin-bars left/right according to your already proven and preferred
method, being careful not to violate the stereo window. As soon as you
are satisfied with the adjustment of the film chips, just press the
other half of the mount into place on its locating pins. The mount can be
easily reopened at any time.
