Here are some photos of Pat's combo viewer. It can be used to view 41x101mm
(Realist) slides, 2x2x2 (separate L & R 2x2 slides) and 80x132mm Medium Format
The lenses are double 36mm dia x 94 mm FL achromats. The resulting optic is
36mm dia x 50mm FL. The results with Realist and 2x2 slides is superb. With
Medium Format slides the corners are clipped and the edges are somewhat unsharp.
One of my slides that had been cropped to 40x40mm looked excellent so perhaps this viewer is ideal for
Focusing is done via the moving tray approach: the slideholder and diffuser move
relative to the lenses and body. A threaded rod is used to adjust focusing so it
take many turns to make major focusing adjustments.
This photo shows the insert removed to allow Medium Format slides to be inserted.
Click photo for larger view
These two photos show Pat's slidebar. It is about 2.5 feet long. Pat added the
rack and pinion for closeup stereos. For hyperstereos it can be removed and the
two cameras (Pentax Super Programs) separated by any desired distance.
The bracket on the near end is for mounting flashes and other accessories. The
sliders go above it so it does not need to be removed.