Originally posted by gkreth The question, up front: Does anybody own both a 70-200 f/2.8 (Sigma or Tamron) and the Prntax 60-250? And if so, do you find yourself using one more than the other?
I own the 60-250 and extensively tested the Tamron and Pentax 70-200.
Originally posted by gkreth I own the Tamron 70-200 f/2.8, and I really like it, especially for night-time high school football.
That's great, especially if you use F2.8 a lot. With the K-3 you probably could manage with F4 quite often, but sometimes there's no substitute for aperture.
Originally posted by gkreth But then I think: Surely dropping from 70mm to 60mm on the wide end would not do that much for me.
It is a significant difference, more so than most people imagine. To me it's one of the main perks of rhe 60-250.
Originally posted by gkreth Likewise, increasing from 200mm to 250mm would not do that much. Especially since I will lose a stop going from f/2.8 to f/4.
That's relatively true. The difference is a few degrees in the horizontal FOV. It's visible but cropping from 24MP will do the same. However, 250mm F4 has a narrower DOF than 200mm F2.8, if that's important for you.
Originally posted by BigMackCam especially at the long end where focus breathing limits the field of view.
That only occurs at close distances.
My opinion is that the Pentax 70-200 is a huge lens, the Tamron 70-200 a large lens, and the 60-250 a surprisingly small lens for what it does. The Tamron and 60-250 can both be used handheld, but the Pentax is still smaller and lighter. For your needs I doubt you'd see much of an improvement by going with the 60-250. What you would loose is a stop of light. What you would gain is a smaller and lighter body, WR, silent AF which works better in live view, and some sharpness (the Tamron is
very good, but not
quite as good as either the Pentax 70-200 or 60-250).