[photo-3d] Re: viewer optics

["John Goodman" <jgood@xxxxxxxx>]

This won't do justice to Paul Talbot's informative post on viewer 
optics but, concerning "eccentric viewing", I recently discovered 
something very surprising. I was playing around with the 
interocular adjustments of several viewers, trying to get the 
best "coverage" with 5p and wider slides, mainly with widened 
viewers originally designed only for 5p.

Until now, I found the wider interocular settings more 
"comfortable" (e.g. when the Realist red-button adjustment 
lever is well toward the right). Such settings no doubt make it 
easier to see the extreme left and right edges of a view, but at 
the expense of the inner window edges.

I discovered, with the viewer lenses about a hand span away 
from my eyes (~8 inches, ~20 cm), that in order to see the 
same small part of the view centered in the left lens (with my 
left eye), and centered in the right lens (with my right eye), the 
interocular lens spacing had to be a *lot* less than I was used 
to. I suppose this "reduced" spacing is approximately equal to 
the mount window separation or the separation of the 
respective homologous points that I was looking at in the slide. 
These distances should be nearly the same (differing at most by 
the on film deviation?), but there probably is some triangulation 
involved since my interpupilary distance is ~68 mm.

So I wound up with the Realist lever slightly to the .left. of 
center, and similar settings with other viewers. What struck me 
was that this much "reduced" interocular setting, once I got 
used to it, was quite nice, and seemed to offer an optically 
more "balanced" view. Fwiw, ymmv, etc.

jeg

 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/