Originally Posted by
I @ M
No Dilemma to me at all really.
I assume that you want the reach a 300mm lens gives?
If you intend to shoot mainly at that focal length then consider the reviews of both lenses and settle on the one that suits your needs best.
If you want the convenience of a zoom lens then I guess the Sigma probably does the job better.
If you want to hand hold the camera and lens then the Canon is a vastly superior piece of gear courtesy of IS, (whether it is 1, 2 or 3 stops of stabilisation).
Sorry, L quality and lens designation don't do much for me, a lens with a reputation rather than a badge will win me over every time.
I am happy with the performance of the Sigma even when combined with a 1.4 x converter wide open to have a lens that Nikon don't seem to want to make. Canon do it all ready with the 100-400 which is a fantastic lens, have you thought about that as a zoom?