Long zooms

[justawriter]

I am considering purchasing a long zoom lens for football and rodeo photos and birding. Does anyone have links to reviews comparing the Canon EF 100-400mm f/4.5-5.6 L IS USM, Tamron AF 200-500mm f/5.0-6.3 Di LD SP FEC (IF) and Sigma 150-500mm f/5-6.3 AF APO DG OS HSM? Any personal opinions (like I have to ask) whether the Canon is worth the extra $500-$700? I shoot a 7D, mostly for newsprint (so everything gets halftoned down to 150 dpi).

[neuroanatomist]

You'll want the Canon 100-400L, partly for the better IQ but mostly for the much faster AF.

[sdsr]

I am considering purchasing a long zoom lens for football and rodeo photos and birding. Does anyone have links to reviews comparing the Canon EF 100-400mm f/4.5-5.6 L IS USM, Tamron AF 200-500mm f/5.0-6.3 Di LD SP FEC (IF) and Sigma 150-500mm f/5-6.3 AF APO DG OS HSM? Any personal opinions (like I have to ask) whether the Canon is worth the extra $500-$700? I shoot a 7D, mostly for newsprint (so everything gets halftoned down to 150 dpi).

You can find some of those compared to the Canon 100-400 here:

http://www.juzaphoto.com/article.php?l=en&article=50

He also has another article which compares the Sigma 50-500 OS with the Canon 100-400, where he finds the Sigma a bit sharper at one end, the Canon at the other, and the OS of the Sigma to be far worse than the IS of the Canon.  He may have had a bad copy of the Sigma; the OS on mine is excellent, probably better than the Canon's (I've read reviews to the same effect).  I rented the Canon and the Sigma and ended up buying the Sigma because I preferred the bokeh from the Sigma.  Both struck me as being much the same otherwise (they cost about the same, too).  I had no problem with slow focusing on the Sigma, but then I don't photograph fast moving things and thus didn't really test it in that way.  I have no experience at all with the others on your list. 

[TexPhoto]

Here is a review that fits your lens choices.  http://www.juzaphoto.com/article.php?l=en&article=50

But I have to say if I was in you shoes, I would be looking to get the best 70-200mm Canon I could and then a 1.4X or 2X teleconvrter.  The Looooong zooms are just not fast enough to capture action.  (fast as in f2.8 vs 5.6)

[Albi86]

I am considering purchasing a long zoom lens for football and rodeo photos and birding. Does anyone have links to reviews comparing the Canon EF 100-400mm f/4.5-5.6 L IS USM, Tamron AF 200-500mm f/5.0-6.3 Di LD SP FEC (IF) and Sigma 150-500mm f/5-6.3 AF APO DG OS HSM? Any personal opinions (like I have to ask) whether the Canon is worth the extra $500-$700? I shoot a 7D, mostly for newsprint (so everything gets halftoned down to 150 dpi).

When you print at 150 dpi halftoned IQ becomes a very secondary matter.

I'd buy the Sigma 120-400 OS HSM. Doesn't match the Canon 100-400 L, but for you intended use you'll hardly see the difference - and it costs considerably less.

[yogi]

just a note about the juzaphoto comparisons: the sigma 50-500 is the old version without os. there is a newer version with os, and it cost more than than the 150-500.