Originally posted by Kunzite Let's not forget about pixel peeping - we will examine the lenses at 200% and look for every imperfection; the old designs were simply not made for this.
The "old designs" have been used on dSLRs of a smaller format, which places MORE demand on lens quality than FF, for years now. They hold up quite well, and will hold up even better on a FF dSLR than on an APS-C dSLR.
Originally posted by Kunzite But it wasn't a widespread phenomenon like it is today, and IMHO people back then had more realistic expectations. Otherwise, everyone would've used medium format, since the difference is obvious at such sizes.
It wasn't as widespread to do the equivalent of "pixel peeping" in film days, but there's nothing wrong with older Pentax lenses, as can be seen by the images taken with APS-C dSLRs - the "lenses won't be good enough" stories are FUD designed to convince you of the supposed "need" for new lenses, but it is for the most part nonsense.
Having said all of that, Pentax didn't have too many high end autofocus lenses, and the ones they did have may not be the best choices; for example, the
28-70 f 2.8 should be updated to a
24-70 f 2.8, and the
80-200 f 2.8 should be updated to a
70-200 f 2.8, since 28/70 really isn't wide enough for the short end of a "standard" or telephoto zoom (respectively) compared with contemporary competing glass, and leaves a gap (though small, still annoying) in the focal length range when using both lenses. It would also be nice if the
250-600 f 5.6 was a
200-600 f 5.6, which would expand the zoom ratio to the ideal maximum of 3:1
and make it "stack" nicely on top of the
70-200.