Seeking an optical light transtandard and quality for my EOS 7D, I hesitated between the barrel and the equivalent thereof. The price and quality of comments in various forums canonist did not hesitate me long. I am delighted with the quality optics. I finally drop without flash shooting indoors happiness! Only regret: I realize that 50mm is a course for me and 70mm have been nice, but it is my way of photographing.