Quote: Yes all will be revealed with the Pentax FF body at the edges, but it may not be such a disappointment, the old Nikon AF-D series lenses in screw-drive are looking very good on the D750. (a thread to follow)Well, most of those AF-D lenses (like 35/2, 85/1.4...) didn't do too well in tests done here at PZ. The new AF-S ones usually run circles around them (I hope Markus does catch up with Nikon's pace of releases soon...) It was similar on the Canon side, even though at times the other tendency you speak of is rearing it's head (when a lens is no longer able to benefit from the smaller image circle, and is coming under pressure from much increased pixel density...)
I think there's somewhat of a misconception about FF sensors being demanding, yes they test a lens's performance at the edges, but there are having an easier time in everywhere else, given a 30X20 cms print size it's the APSc sensor that tests the lens's resolution and struggles the most purely because of magnification.
My findings from the D750 and D7100 with the Tamron 150-600mm and the Nikon AF-S 70-300 VR both of which are only decent on APSc, are that they suddenly look more like quality lenses on FF.
I think many will be pleasantly surprised by the results from some of this old Pentax glass, but even that obviously can't redeem the lack of modern designs.
I think if things go forward we will be seeing a lot more re-badged Tamrons!
Well, if Pentax is going that route - rebadges - I think they're doing themselves no favour in the long run. Not to mention that Tamron is still pretty short on primes, and even the recent 1.8 twins are but a step to amending that (unlike Sigma who has filled out the high-end lineup nicely (maybe a 135 would be handy, but just maybe - I have no idea how many people are interested in this), and may get to the mid- and lower range someday). So they'll have to get to the drawing boards themselves.