I borrowed a Canon 70-200L non-IS
from a friend recently and took it for a photo-shoot at a little GA
fly-in. I was absolutely blown away by the lens' sharpness, and the lack of IS
didn't seem to be a problem, but 200mm is a little too short for me, so I ended up buying a Canon 100-400L.
Another option is the Canon EF
70-300mm F4-5.6 IS USM
. It is about a third of the price of a Canon 100-400, has a decent range and the image quality is quite good. I've been using one of them for over three years.
I've had mixed experiences with Sigma lenses. The 17-70mm F2
.8-4.5 Macro (non-DC) that I've had for a couple of years, is excellent, I' am very impressed with the image quality it delivers. The wide angle zoom 10-20 proved a bit of a disappointment.
As for the wide angle lens - 17mm is not enough for an EF
camera, IMHO. Sigma 10-20 or Canon 10-22 seem much better options. I am currently using Sigma 10-20; it is okay, but not great. There is plenty of good feedback on this lens on the net, I must just have a bad copy. Looking at exchanging it for Canon 10-22 in near future.