[Rondec]

I disagree. If I wanted Canon, that is what I would of had. BTW, Canon has it's own issues with it's AF, and more than one photog had to change systems because of that(google it if need be, but not to start another issue here). The reason for the f2.8 zoom was supposed to be quality of the shorter zoom ratio lens, the aperture blades, and WR. So far, the 17-70 I borrowed has the quality, and it made lovely sunstars, it at least has a mount base gasket - though not full WR capability.

David

Photozone really likes the DA 17-70. They felt like it was the best "normal" zoom for the Pentax (made by Pentax). Sorry that the DA * 16-50 didn't work out for you. Pentax SMC DA 17-70mm f/4 AL [IF] SDM - Review / Test Report - Sample Images & Verdict

[simico]

David, I switched from DA 17-70 to DA* 16-50 and I really regret it! I'd switch back to 17-70 or the new Sigma 17-50, but I don't want to lose money again.

Imho DA 17-70 is an excellent lens, I used it at f/4 in 95% of the time. Regarding WR, I just used a small plastic bag to cover the lens and my cam in the few cases when I had to shoot in rain or snow.

[David&karen]

I use Aperture 3 on my Imac and that makes it easy to compare lenses as separate 'Projects', so I can do side by side comparisons. From what I saw of my friends 17-70 vs all three of the defective lenses I got, the 17-70 won hands down, and that's not even counting the 70mm setting the 16-70 can't do. I do know the 17-70 has a mount gasket to keep junk and water out of the camera, so that really makes it a better choice I think than the Sigma, though I am undecided as of now.

David