Flat-field lenses for stereo: Bad or Good?

[P3D Sam Smith <3dhacker@xxxxxxxxxxxxx>]

Having finished the testing stage of my new Stereo Pro, I graduated to
taking REAL stereo shots on the weekend. The results were far better than
expected.

My initial testing of the 80mm Yaskimar lenses showed that they lost quite a
bit of sharpness at the edges shooting at 3.5. But it seems I had a flaw in
the way I tested the lenses. It was based on shooting wide-open at subjects
close to infinity eg- a skyline. This indeed showed me that the lenses
weren't very flat field. But who shoots stereo wide open with nothing but
distant objects as subjects?  it's true that those into hypers may, but most
of my subjects have near and far depth.

If I'd tested as I regularly composed in stereo, I would have found that
when the lenses were focused at infinity, the edges focused a lot closer.
This to me has a great advantage to the average stereo user. Most of the
time when I am doing an average scenic, my foreground is in the bottom
corners. The top is mostly sky with little detail. Would it make sense that
this type of lens would perform better for most subjects than a strictly
flat-field lens?

I gave up my Realist 2.8 years ago because my 3.5 outperformed it. perhaps
this is why.


sam


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