Originally posted by tux08902 I'm aware the Tamron 17-35mm isn't available for Pentax anymore. It used to be though, and I've managed to find one. If I can get it for cheap enough, then I might go for it. Is it a good lens?
Yes. It's definitely better than the kit lens. Having said that, there were things about the kit lens I miss... like instant manual focus override without flicking any switches, and the nifty little tab on the lens hood for rotating filters. Also an equivalent of 26-50mm is a bit odd... but it's great for me since I still shoot 35mm film and so can take advantage of its true range. Anyway it's a very good semi-wide lens on the dSLR and if you can find one at a good price I'd go for it.
As for telephoto, the Tamron 70-300mm is a great choice for the money. It does have flaws, which is why I'm now waiting for a Pentax 55-300mm (will post some test shots when it comes)... but the Pentax is well over twice the cost. Personally I'd forget the Sigma since it doesn't have the value appeal of the Tamron and nor is it significantly better (especially past 200mm).