120-400 sigma vs 100-400 canon (1 Viewer)

Hi Folks
I notice in sales ads the sigma is approx half the canon price. My question is: Is the Sigma a good buy up against this L lens Canon? your views would be most appreciated. Looking at fitting it to a 60d.

This should help you out http://www.birdforum.net/showthread.php?t=160849

Thanks Jaff. you pointed me exactly where i needed to be

the canon is so much better!

No, no, a thousand times no....

I once had the money to buy the Canon, but to me £1000 was the cost of a car, so I could not bring myself to do so, a choice I bitterly regret.

I bought a Tamron 200-500 - optically good, but no good for Birds in Flight under grey British skies as the autofocus hunted from one extreme to the other.

This I traded in for a Sigma 120-400 OS which was USELESS at 400 mm even at f/8.

This I traded in for a Sigma 50-500 - which was by far the best lens I have owned and what I should have bought in the first place with what I was prepared to spend, but I had to sell it to pay off part of the credit card bill, so I ended up with a rechipped Sigma 300mm f/4 from eBay which I have to use at f/8 to get any keepers at all.

MORAL: if you can afford the Canon 100-400 L BUY IT. For Canon users, there are those with the 100-400 L or the 400 L, and there is everyone else.

Hi . If you can purchase canon overall is a better lense in quality.
http://www.juzaphoto.com/article.php?l=en&article=50
I decide to purchase it because it is a good choice in wild photography with greater versatility.