Quick beforehand conclusion:
I will keep the Tamron lens and try to sell the Sigma one, and happily so.
I was looking for a wide angle lens to take on a trip to Morocco for photographing landscapes and cities. The two lenses I tested were the only real candidates. The Tokina 11-16mm wasn't available at that time. So I read some reviews about the Sigma and Tamron lenses and my conclusion from that was that they both have pros and cons on some aspects and that I couldn’t really decide just from the specs and reviews. Major aspects that struck me as important were that the Tamron lens should be very sharp in the center but lose a lot towards the edges. The Sigma was supposed to start with less sharpness in the center but have a better sharpness in the corners. While the Tamron should have better (or easier to correct) distortion behavior, the Sigma would be more resistant against flair. Built wise the Sigma would have a better and faster focusing system and a more convenient ...
Read More →