Hello everyone, I'm looking for a new lens for canon. I currently own the Sigma 10-24 f.4 or something like that. And also a 50mm 1.8. I want a not to expensive really sharp lens for landscape photos. E.g. Between 18 and 40mm. I have looked at the Sigma 35mm 1.4 prime and the 18-35mm 1.8. I'm not sure how sharp these are or if there any any better options? Thanks.