Re: Realist vertical registration

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

Paul Talbot writes:

>I'm having a problem with the chips from one of my Realists. 
>Within a single roll of film, the vertical registration seems
>inconsistent.  On some shots it looks perfect; on some shots
>the left image seems too high; on others the right image seems
>too high.  The vertical registration seems to vary as the
>roll progresses, rather than being strictly random, but I
>have not positively determined a pattern.

Someone mentioned this a long time ago and I think I see it in some of my
pictures with certain Realists but not often.  The effect is very small for
me to be important and using Albion mounts the vertical registration can be
easily adjusted.  Using RBT mounts is where this situation manifests
itself.

I tend to believe that the tension in the film might cause it to move a bit
up and down in the film plane path.  Is there a little bit of slack there?

>Is it possible I am confusing vertical registration with
>something else (like camera not level with horizon), is
>there something really whacky with this Realist, or is
>this a common and/or normal thing?

As we've discussed in the past, a (non)leveled camera has nothing to do
with vertical registration.  This is a real phenomenon (and I believe common
in many stereo camera, not just the Realist) that is recognized now that
perfectionists are using RBT mounts.

>I am now wondering if I am having this same problem with both
>Realists, as I previously noted significant vertical registration
>problems on some images mounted by Kodalux.  Those shots were
>taken with the other camera.

I would not trust anything mounted by Kodalux in terms of vertical
registration.  Better remount those in RBT mounts to check for yourself.

George Themelis


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