Originally posted by MrStupid I'm not greedy.
Being that I have no intention of going back to full frame I could buy these and hold them until FF comes out (when that happens 24-70 ain't gonna be the work horse anymore, it's back to the 35-105) and sell them but then I would be a... well you know.
https://www.keh.com/251524/tamron-35-105mm-f-2-8-aspherical-sp-requires-adaptall-lens-67
I don't know If it's on par with the lens that got me to switch from Nikon to Pentax the 35-105 3.5 A, which will also be a great lens again when the FF comes out and a lot easier to manual focus than the 24-70. (Manhattan fashion & beauty photography and especially character study photography, indoor and studio it never comes off the camera. Had three of them.) But this one is constant 2.8 and it looks pretty good here on Pixelpeeper. A little barrel distortion not seen with 35-105A but not bad.
https://pixelpeeper.com/lenses/?lens=13115 They also made a 28-105 2.8 but like the PK A 28-135 it's soft and not made for Pentax anyway.
Enjoy
The 24-70 zooms are usually used on full-frame cameras. On crop-format cameras, people usually use wider lenses, like 16-50 or 17-70 lenses.
Those 35-70 or 35-105 zooms are usually older lenses, dating from a time when it was very difficult to manufacture good quality zooms going from wide to short telephoto. I am not saying they are necessarily bad lenses (I have an excellent Minolta MD 35-70 Macro), but they are certainly less convenient on full frame than a 24-70 or 24-105 lens. For a future Pentax full-frame, I'd rather be stocking on the Pentax FA 24-90 than on the Tamron 35-105!
Cheers!
Abbazz