Re: Vs: Which 300 zoom should I buy?

[Joseph Tainter]

I have the Sigma APO Macro 70-300 f4-5.6. Consumer lenses in this class 
tend to be weak somewhere, usually at the long end. This Sigma is 
perhaps the best in class, but weaker at 300 mm. At 300 mm. you have to 
go to f16 to get truly sharp images (which usually means a tripod). 
Otherwise images are weak laterally. I've mostly retired it (in favor of 
the Sigma AF 70-200 f2.8), but keep it for its macro capability. Still, 
it is overall a very sharp lens, and a bargain for the price. I've shot 
some images with it at 300 mm. that I liked much, and others that I 
found disappointing due to the lateral softness. Here's an example of 
one I like:

http://pug.komkon.org/03mar/djnmsqsn.html

Here's one using 300 mm. in macro mode:

http://pug.komkon.org/03may/buttrfly.html

Some on the list like the FA 80-320.

Joe