Finally I've bought a lens for landscape-photography: it's a Sigma 10-20mm F4-5.6 EX DC HSM. Actually I preferred the Tokina 12-24mm lens, but there were none in eBay, at least not within a price range I wanted to pay. So I searched for other ultra-wide-angle lenses and I was lucky to purchase the Sigma for a low price :)
So far, I'm very satisfied with it. I read a review about the Sigma, where the author also said, that it wasn't easy to get used to the wide angle, because you'll get so much stuff into the picture (I hope you understand what I mean^^). This is one point, I have to agree. The first look through the viewfinder was amazing, b