As Im learning photography, Im also learning what I enjoy and what I dont. One thing that I have been loving is doing landscapes and cityscapes. That being said, Im in the market for a wide angle lens for my Canon but I need some input from more advanced photographers (so anyone reading this basically haha). Im looking at: Sigma 10-22mm 4 5.6 which sells for about $650 at a local store Canon EF-S 10-22mm 3.5 4.5 which sells for about $840 at the same store so about $200 more. Im thinking the main reason the Canon is more expensive is because its 3.5 instead of the 4.0. And because its Canon. My question is, from my basic photography that I have been learning, Ive been doing city and land scapes with a tripod and using a small aperture (deeper depth of field). While there are instances where a shallow DOP might be interesting, Im thinking at 4.0, I should be able to achieve this, thus making the 0.5 difference kinda pointless for the type of photography I would be doing with this Is my thinking off? Am I overlooking something? Are there other major applications for a wide angle lens? Thanks for taking the time.