P3D Re: PHOTO-3D digest 3248

[roberts@xxxxxxxxxxxxxxxxx (John W Roberts)]

>Date: Wed, 17 Mar 1999 00:22:52 -0700
>From: Rob <lilindn@xxxxxxxxxxx>
>Subject: P3D Re: PHOTO-3D digest 3248

>...using SLR's frees you up to use other focal lengths, or faster lenses 
>for nightscapes, but excellent shots "on the fly" are grabbed by cameras 
>like the Realist.  Many stereo users use twin-camera rigs or
>slidebars for their competition slides, while shooting countless snapshots 
>on a Realist for personal use.

That's an interesting viewpoint - I can generally take snapshots and
sequences of stereo photos much faster using twin SLRs than with a Realist -
and that's with SLRs that have manual focus and manual film advance!
I find the exposure using slide film and a Realist to be extremely sensitive
to changes in lighting - if I don't painstakingly check a light meter
pretty frequently, the exposures will usually be off. (Of course at noon
on a clear day, repeatedly photographing the same subject, the checks can be
infrequent.)

>Is it easy to perfectly synchronize the two shutters perfectly?   

How many picoseconds differential are allowed for "perfect" sync? Judging
by the results from stereo photos of fast-moving objects, I can routinely
get better than 1/500 second synchronization (though if I let the contacts
get dirty in my custom wiring or if the batteries get very low the results
are worse).

>From a certain point of view, it could be argued that if sync in a twin
rig is better than ~1/200 second, then it's better than the
synchronization of a Realist. :-)

John R


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