Which PC lens?

[BrianSmith]

Apologies. I posted this on DPR a little while ago where it is disappearing without trace.
Perhaps the cognescenti here may have more experience to give me some advice ;o)

I'm looking at good used examples of the 28mm f4 PC and 28mm f3.5 PC lenses as I cannot afford the new PC-E lenses.

From what I can read the f4 lens might be better in edge sharpness but the f3.5 may be sharper overall at wider apertures. Ther may also be other differences in the degree of CA but nothing seems consistent.

Can anyone give me any advice on which would be the better choice when the primary use would be panoramas?

[Guy Van Hooveld]

I have transformed a non-AI 35mm 3.5 PC lens and I am very happy with the results.
I have no experience with the 28mm version but you could have a look at Bjorn Roslett's site for more info
Look for the wide angles section in his lens reviews.
http://www.naturfotograf.com/index2.html

[Luke Kaven]

I've had the 35mm f/2.8n PC and the 28mm f/3.5 PC. Both were extremely sharp unshifted, even wide open, verging on Leica quality. Shifted however, you are relying a lot on edge performance, and it is advisable to use these lenses only stopped down when they are shifted. I can't comment on the 28 f/4 versus f/3.5. Clearly the 28 is preferable for most things, making it possible to photograph a building from across the street in most cases. A 24 would be just a bit better.