[MF3D.FORUM:1375] Re: Larger aperture size for twin rig shots?

[Paul Talbot <ptww@xxxxxxxxx>]

Still catching up on things that transpired during my
absence...

Greg Erler (sic) wrote:

[re: how much room to work with twin camera shots]
> 
>   Thus with 55mm film gates you should be able to still
> have 55-1.35mm or so of usable area. Any non-parallel aiming
> of the cameras could easily waste 1mm or more so that might
> be a bigger effect.
> 
>   Stereo base shouldn't matter if you keep the OFD under
> control.

It would take a lot more brain power than I have to think
all the way through the implications of that observation!

Here's where I see a potential problem: as the stereo base
increases, so does the "non-overlap" image area at the edges
of each image.  (George Themelis has posted a formula for how
to compute the non-overlap area.)  Is it possible to have a
large non-overlap area while not violating Greg's condition
"if you keep the OFD under control?"  It seems to me that when
dealing with twin camera hypers, it is the non-overlap area
at the edges, more so than the OFD, that restricts the maximum
size of the mount apertures.  But maybe I'm confused, as usual?

Another factor that occurred to me after my post was that using
two stereo cameras will give different answers depending on how
the images are mixed in the final pairing, because of the built-in
stereo window.  For example, using the left camera's left image
with the right camera's left image will give a different result
than using the left camera's left image and the right camera's
right image.

Paul Talbot