Originally posted by Crazykev m going 2 lenses. the kit lens (18-35) seems great for everyday picture taking.
You mean DA 18-55 or DA 18-135? The latter is much better than the kit lens.
Originally posted by Crazykev So far I really like the sigma 10-20 for pentex. Thanks for the suggestion. Would i have to get a adepter for it?
No. Just make sure you get one with the Pentax mount (often called K-mount), rather than Nikon, Canon, etc.
Originally posted by Crazykev Reasons why i like it: 1 it is 10-22 so i can kind of play around with it and see which size i actually like. 2 its a little bit cheaper then the Pentax HD 15 mm so i would not feel too bad buying a WR wide angle when/ if it gets made.
Good reasoning. A lot of us have agonised about the choice between primes and zooms in wide angles. I love primes for their image quality (IQ), compactness, light weight. But the versatility of an ultrawide zoom is great for situations where you can't "zoom with your feet" - like shooting trees in a dense forest, or standing on rocks in a stream or shooting when pressed against the back wall inside a building. And there is a huge difference in field of view between 10mm and 20mm. One prime (e.g. 15 or 21) would be far more limiting.
Two notes of caution.
1. When you get towards 10mm there will always be a lot of distortion. If you don't want to spend the time post-processing your images with good software (DxO ViewPoint plug-in for Lightroom or DxO Optics Pro is very good), you will either need to live with the distortion, or get a Pentax-branded lens and rely on in-camera distortion-correction of jpgs (the K-S2 has this feature, but it doesn't work with third-party lenses). That's a good reason to consider the DA 12-24, even though it costs a bit more (about $450 or so second-hand).
2. If you think the 16-85 seems huge, the ultrawide zooms will too! They all tend to be bulky because they need a wide front element (77mm in the case of the DA 12-24 and also the Sigma 10-20 f4-5.6, even larger on some other UWA lenses). Not always easy to stow in a bag, particularly with the lens hood reverse-mounted.