In article <4fajeg$rl5@firebrick.mindspring.com>, PWILS@dbsnotes.dbsoftware.com says...

>I'm curious as to how big the image circle produced by perspecitive control
>lenses such as the Nikkor 28 PC and the Canon FD 35 TS is.
>Specifically, I'm wondering if they have enough coverage for medium format
>without using the perspective controls. For example, in 6x7, the Nikkor 28 >PC would be about equivalent to a 14mm lens in 35.
>Yes, I would like to have a super wide angle for Pentax 67.

Ah, sounds neat, but...... In the case of both Nikkor 28mm PC's, using
the maximum 11mm shift on 35mm with the lens set for worst case coverage
(shifted diagonally off the upper corner of a vertical, which Nikon rates
as 7mm max recommended shift), vignette just begins to appear when no filter is used (and corner performance is just acceptable at f22, worse wider).
If you figure the 35mm frame diagonal to be 43-44mm, and add about 10mm x 2
to it, it gives you a circle at infinity of about 63-64mm - well short of
the coverage neaded for 6x7 (and the lens back-focus would be too short to
mount to a Pentax, anyway). Try the 35mm fisheye, or 45mm rectangular lens
for Pentax....
Hope This Helps