P3D Mark Shields Ortho Q

[Michael Georgoff <Michael_Georgoff@xxxxxxxxxxxxxx>]

Mark Shields said:

>Using one of the simple formulas for focal length, distance
>to subject, and stereobase, I ran my rigs and a couple of
>other cameras through the mill. I came up with the idea
>that my beamsplitter, with a 70mm stereobase on a 50mm
>lens, is somewhat hyper (has a bigger stereobase than
>it should) compared to, say, a Kodak or a Realist, which
>have 70mm with 35mm lenses--in effect, the 50mm lens I'm
>using brings the subject closer so should have a shorter
>base.

Mark, did the formula you used for base specifically take focal length
into account?  I wasn't sure from your post.  I'm pretty much clueless
about beamsplitters relative to "classic base math", so I'd be
interested to see comments from others on this.

Michael Georgoff
San Jose, CA



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