I have a Canon 350D and I would like to pose to you a question about lenses. I currently own: - Canon EF-S 18-55mm f/3.5-5.6 - Canon EF 70-300mm f/4-5.6 IS USM - Canon EF 50 mm f/1.8II I want to expand my range of possibilities with a wide-angle lens. I will use it mainly for landscape (natural and urban) and my key parameters are that it is suitable ALSO for low-light situation and a maximum of around 400 ($510 approx.) I am considering the following lenses and I would appreciate a lot if you could let me know your experiences (pro's, con's, examples) and recommendations so I can make an informed decision when buying. - Canon EF 20mm f/2.8 USM - Canon EF 24mm f/2.8 - Canon EF 28mm f/1.8 USM - Canon EF 28mm f/2.8 - Sigma 20mm f/1.8 EX DG Aspherical RF - Sigma 24mm f/1.8 EX DG Aspherical Macro - Sigma 28mm f/1.8 EX DG Aspherical Macro Many thanks for your help!!