P3D Spacing problems with my RBT X4

["Alan Mahon" <alanmahon@xxxxxxxx>]

All measurements were across the film plane.  When I say the apertures are
too close I mean the 24mm by 36mm rectangular openings inside the camera
which determine where images are placed on the film.  The principle as found
in the Realist format is that the apertures are 3 frames or 15 perforations
apart.  Try it for yourselves with a piece of film.  In the case of full
frame RBT cameras the apertures should be 16 perforations apart which is
76mm.  This has nothing to do with creating a window in the camera it is a
function directly related to how much film is advanced each time.  A window
may be created in the camera by placing the lenses slightly closer together
than the apertures.  There is a remarkable tolerance on the part of users of
these cameras because the widest recommended mount has an aperture of 33mm.
This misses the point.  Proper design would result in exposed film with
images evenly spaced, indistinguishable from film from any flat camera and a
full range of processing options available.  What is surprising is RBT work
to a tolerance of 0.1mm to 0.4mm height adjustment being available with
their mounts.  So why not get the camera right.