Originally posted by cousinsane I am not saying all Pentax lenses will perform badly on FF. I am only talking about the old Takumars. My brick wall test of the SMC takumar 28/3.5 on a K10D showed pretty soft corner. Too bad that I deleted all the test images(raw file) when my laptop hard drive was running out of space. I can only prove that I am not making this up by pointing to the following lens review written a year ago, where I mentioned the soft corner issue.
Pentax Lens Review Database - 28mm F3.5 The fact is, some lenses will do better than others, and some of those old Taks are very good lenses.
However, like all lens lines, they have some good, some not so good.
Corner performance generally does get better when stopped down, so a lens that is iffy in the corners wide open may well be just fine a couple of stops off full aperture, and there are a lot of applications where a little corner softness just isn't important anyway, so it really is a bit of a specious argument.
It's kind of a moot point though, since there isn't a snowballs chance in hell that Pentax could release a full frame camera without releasing a set of lenses to go with it almost concurrently, and as almost six years into APS-C digital they still don't have a full lens line released, I'm just not seeing much chance of a full frame camera.
The only reason why Pentax didn't fall flat on it's face with the *istD was because they had enough glass out there that would work. They've been very slow about fleshing out their lens line for APS-C digital.
My guess is that with the 60-250 in production (I saw an incredible shot from it today), they will soon start ramping up for 645 digital lens production so that when that camera is released they will have a lens set ready for it.
It's imperitave that they have lenses in place and ready to buy with that camera. This is pro territory, and they won't buy if they think the support is half assed.
This presumes that it hits world wide release. If it's a home market only camera, then it's hard to guage what they will do.