Re: 4x5 stereo

[bercov@xxxxxxxxxxx (John Bercovitz)]

Yeah, I don't know why that is.  Theoretically, MF can reach the 
limits of human vision for any but the highest contrast images 
(like black lines on a white background).  With 4x5, when you 
look at a pair, you don't feel like you're pushing the edges of 
what can be done.  As a bonus, Stephen gets a wider true angle 
of view with 4x5 than the other formats give because he is using 
a little shorter than normal lens.  It's about as wide as Don 
Lopp's wide angle MF viewer but with much more resolution.

As I've said a few times before, I sat down once and looked at 
lens charts and film charts and found that good 35 mm format 
lenses can be better than any film a sane person would use for 
stereo, and 4x5 film was better than what was possible in a 4x5 
lens.  I'm talking about viewing from the center of perspective, 
of course - the films are actually the same in absolute terms.  
MF was a nice balance of what film can do vs what the format's 
lenses can do.  So MF is a practical choice but probably 4x5 
will edge it out for sheer angular resolution given top lenses 
and film, etc, in both formats.

As to wide angle or normal angle stereo systems, the wider the 
angle, the worse the resolution because film limitations show up 
and to some degree lens limitations appear.  Stephen's lens is 
close enough to normal that this isn't a problem.

John (Where's my ASA 25 Kodachrome 4x5?) B