Canon EF100-400mm f4.5-5.6 L vs Sigma 50-500mm F4-6.3 EX DG

[chaps1150gs]

I have seen some great results on the web with both these lenses fitted to a Canon 20D. Is it worth the extra cost for the IS and lower f stop with the Canon or is it worth buying the Sigma for the extra reach?

[paul goode]

I have seen some great results on the web with both these lenses fitted to a Canon 20D. Is it worth the extra cost for the IS and lower f stop with the Canon or is it worth buying the Sigma for the extra reach?

I think it depends how you plan to use the lens. When I had the 50-500 I used it in the way I now use the 500mm prime, ie on a tripod, beanbag or somehow supported. Apart from panned flight shots I never got on with it handheld. Assuming you've got a decent tripod and head and work from fairly fixed locations then a S/H 50-500 (£400-£450 ish) would be a great buy, and I think the AF is faster on the Sigma.
If you're planning on buying new and also need the tripod and head,I'd go for the 100-400.
The 100-400 i use as a walk around lens. the IS makes handholding a doddle, but in a hide I still carry a small beanbag to put the lens on. If you find 400mm isn't enough put a 1.4x tc on it to get to 560mm. Have a look at Keith Reeders recent images to see how well this combination works!!

Both lenses will produce cracking images so as ever its a trade off of which aspects of the lens are more important.

Bottom line. If the choice is between those 2 lenses new I'd go for the 100-400.
If you're happy with working from a hide or carrying a tripod, look out for a S/H Sigma 500mm f4.5!
If money's tight S/H 50-500mm, and to confuse things even more the Tamron 200-500 may be worth a look. DOC's gallery looks great, but there are many comments about this lens needing good light, so it may not be so good in Blighty in January!

Hope that helps

Paul

[postcardcv]

I think Paul has summed up the pros and cons of these two lenses very well. The best thing would to try both for yourself and see which you prefer in the hand. As was mentioned, if you don't want to use a tripod then the 100-400 is a clear winner.