[ScooterMaxi Jim]

My experience pretty much mirrors Gibby. I certainly don't worry about it when shooting with the 85mm. I have gotten good shots with my 75-150 on the long end, but it can be hit and miss. If you are shooting architecture, you'll see it if there is any movement at all. So its just a matter of the situation.

Most fast lenses have issues when shot wide open. The advantage of having good f/1.4 lenses (50mm and 85mm) is that by f/2 the quality is very good, and they focus very nicely wide open if you are using focus peaking. Only in extreme conditions do I actually shoot them wide open - even on my "regular" bodies. As for modest PF, usually it cleans up easily if you're using a decent converter program or even in post.

Obviously, you are going to have hit and miss situations when you adapt lenses that weren't designed for the format. That's part of the charm. However, I have several high quality images from adapted lenses (as indicated in the album linked above), from various fairly cheap c-mount lenses and good quality K mounts.

[willsteeleuk]

I vote for m42 adapted lenses, a lot are fun to shoot and have surprising image quality for the price.