Re: [photo-3d] Re: Camera separation in stereo photography

["don lopp" <dlopp@xxxxxxxxxxxxxxx>]

I am at a loss to explain why it is tha t reguardless of which viewer I use
for M F views 45 mm 60mm ,70mm,85 mm or 100 mm lenses the deviation problem
appears to be approximately the same except in degree even when using 150mm
lenses whih doesn't fit any of the theories expressed so far. I often talk
about ortho viewing but it is not allways available and I think sudued
deviation is more valuable making things look more natural especially
considering that in my opinion very few people seeas much stereo when
looking at a scene in the raw as compared with looking into a viewer-I have
seen this when walking around Mt Rainier and showing them a stereo view of
the scene they are looking at , taken on a previous trip. This is where I
think M F really comes ouit ahead of 35mm stereo. I never heard such
comments when I was with Warren Callahan when he showed his 35 mm slides to
fellow travellers largely , in my opinion , because 35 mm stereo just does
not have the quality of MF { Isaid that] based on my personal experiences
and prejudices. Don
----- Original Message -----
From: "Abram Klooswyk" <abram.klooswyk@xxxxxx>
To: "PHOTO-3D" <photo-3d@xxxxxxxxxxx>
Sent: Thursday, June 29, 2000 2:36 PM
Subject: [photo-3d] Re: Camera separation in stereo photography


> Sergio Baldissara (29 Jun 2000):
> >Fusion capacity physiologically varies between individuals:
> >some skilled stereo watchers are even able to freeview
> >stereocards in parallel format.
>
> I don't believe the ability to freeview is the same as, or
> even related to, the capacity to view large convergence
> differences. These are essentially different skills.
>
> don lopp (28 Jun 2000):
> >I think  the deviation numbers given are erroneous or being
> >measured in a strange way  ?
>
> The strict definition of deviation is something like:
> The Deviation of a pair of homologues on a stereo picture is
> the difference between the infinity separation on the stereo
> picture and the separation of that pair of homologues.
>
> In looser usage, for the infinity separation (which is often
> not measurable) the far point separation can be substituted.
>
> In the stereo base discussions often the deviation of the mask
> aperture is used. Its separation is easily measured on the
> mount, and it is mostly known already. Then only the
> separation of infinity homologues or of far points have to be
> measured to compute the mask deviation on the mounted slide
> (or card). This is often the largest deviation of the slide,
> unless something gets "through the window.
>
> Hardly any errors can occur in my opinion (if we stick to the
> right terms :-)).
>
> Abram Klooswyk
>
> BTW: Can replies to posts please quote only the necessary, not
> whole messages?
>
>
>
>