Originally posted by ChromaNoise I've been an owner of a Pentax K-5 for several years now. I got the camera at a discount and at that time I thought it was a pretty good deal. However, throughout the years I've been trying to find a decent walk-around zoom lens for it, without much success.
What I found that literally all of the "digital" lenses don't provide enough quality the sensor otherwise would be capable of. Since I tried many film lenses, I know what the sensor can do, but the obvious caveat there is the lack of focal length on the wide end. Regarding "digital" lenses, another issue has surfaced and that is a ridiculously small focus throw. My Pentax 17-70 has ruined quite a few shots because of inaccurate AF and accurate MF is impossible with that short throw.
It seems to me that Pentax, including competitors essentially killed off APS-C quality by manufacturing lenses meant for full-frame sensors. For me those are prohibitively expensive, not to mention they don't represent a good value (ala I'm not getting a 5 times better camera for 5 times the price). Since I'm a hobbyist, I'm not making money on photography either.
At this point I don't think there is a way to salvage my camera, since there won't be any normal zoom lens for it ever, that matches its sensor. I understand that people will say I wanted too much for too little, but I just wanted to share my experience.
The 16-85 is an outstanding lens. Downsides are it's not 2.8. Upside it's sharp wide open and usable at all focal lengths. Flare and contrast are well controlled when shooting into the light. I'd say it's one of the very best zoom lenses I've ever used when you consider it's focal range, the fact it's WR, the optical quality through the range, the size and price. And I've got a few lenses to compare it to. Including most of the limiteds, DA*s, and FA* glass.
Biggest issue for me is the focus ring. Since there is no infinity focus on it, I have to always make sure I have an additional lens for anything that requires infinity focus, such as star trails.