Originally posted by CarlJF I had the F 35-70 in the film days and, even then, I didn't considered it very good. It was good at f8 at about 50mm, but quite average to poor at larger apertures and extereme focal lenghts. Although it could be fun to try on a K-1, I would expect disapointing results.
I also used a FA 28-105, 2nd version, which was significantly better than the F 35-70. This was my main lens for many years, even on the first generations of digital bodies. However, compared to modern lenses, it simply didn't cut it anymore on the newer bodies (16MP+). I get rid of it about two years ago when I came to the conclusion that this will not be a lens that make sense use on a FF digital camera. Again, nothing wrong to try it, but I don't see the point of paying a lot of money to get a hires FF body to use a subpar lens.
I'm quite sure that the new 28-105 is a way better choice than thse two lenses.
Although old prime lenses aren't that different from modern ones, zoom lenses have improved greatly in the last 10-20 years. I would expect most of the zooms from the 80-90 to be average, at best, relative to 2016 IQ standards.
I had 2 copies of F35-70, and 2 copies of FA28-105 powerzoom.
Both copies of F35-70 were sharp wide open at any focal length.
I could shoot with them wide open all day long.
FA28-105 powerzoom is the best autofocus consumer 28-105 zoom from film days but needs to be stopped down for similar amount sharpness like F35-70 wide open.
I sold one copy of F35-70 and both copies of FA28-105 because I have A35-105 which is more usable to me than FA28-105.
I believe that new D-FA 28-105 can't beat A35-105 in IQ