Okay- so I have a 7d with the 28-135 kit lens and a 50mm 1.8. I have been finding that I have been missing a lot of opportunities because I don't have a wider lens. I'm not looking for a UWA because the person I do most shoots with has a 8-15mm f4 L. I'm really wanting something that would also fit on a full frame body because I will DEFINITELY be going that route sooner than later. I was looking into the 16-35 2.8L along with countless others. The problem is that I'm really unsure of how wide that would be on a 7d body. I just don't know what to go with, and would appreciate any guidance! Thanks in advance!