I have a canon 550d and various lenses, but i really want a good quality not to expensive 100mm- 400mm for wildlife photos. I,ve read some articles on sigma and tamron lenses , but i have only used canon lenses. Any views or advice welcome
Depends on your budget?
Sigma 120-400mm f4.5-5.6 OS £500-600
Sigma 150-500mm f5-6.3 OS £600-700
Canon 100-400mm f4.5-5.6 IS £1100-1200
Sigma 50-500mm f4.5-6.3 OS £1100-1200
The wildlife crowd like the 50-500mm f4.5-6.3 think its a better lens than either of the other 2 sigma's, the canon loses out on IS, but that's because the lens is 11 years old, 1st gen, but its still a good lens if you find a good copy. Personally, to get the best from these lenses you'll still need to step them down an f-stop or so, light then becomes a factor with your camera settings to achieve the right apertures and shutter speeds. They ain't fast lenses