EF 100mm f/2.8 Macro - Canon vs. Sigma

[wcstory]

I do some macro shots from time to time and want a good macro lens. I've been looking at the Canon EF 100mm f/2.8 Macro USM and the Sigma 105mm F2.8 EX DG.

Both are f/2.8 have a minimum focal length of about 12".

Canon is heavier than the Sigma by about 125g

What I want to know is the the stuff that doesn't show in the specs....... Feel, Image Quality, etc.

Your thoughts,
Bill

[oldsquawk]

Both lenses are very sharp. The Canon is a hair sharper at f 2.8 and f 4. Frrom f 5.6 to f 11 you would have a hard time telling the difference between the two lenses. The Sigma does get 100 mm longer than the Canon lens when focused at 1:1. The Canon has internally focused lens elements and the lens does not get longer when focused at 1:1. I use a lot of electronic flash when shooting macros. The Canon lens is ewasier to use with flash since it does not get longer. Otherwise the two lenses are very similar in use and feel.