Lens used with Canon 1Ds and 1DMKII.
I purchased this lens used to double as not only a 1:1 macro, but also for medium telephoto work.
First off, Auto focusing. It's slow, a little slower than expected, but not a shock, nor is AF needed for all my macro work or most of my telephoto work.
For macro, this lens truly shines. Sharpness, detail, color and contrast are just great...from wide open and on. I've not stopped down further than f/16 with the Sigma, and the macro images are still wonderful.
For medium telephoto, this lens lacks in key areas. Compared to my 70-200/4 L in controlled conditions and at similar settings, the Sigma demonstrates far less sharpness, detail, color and contrast than the Canon zoom. Of course, my Canon zoom is slower than Sigma by a stop, however the Sigma prime takes a back seat to the Canon zoom in the medium telephoto department.
Apples and oranges; yes. However, Sigma's 'orange' is trying to also taste like Canon's 'apple' but does not succeed. Still, I do find the medium telephoto images from the Sigma still usable, and it does fine wide open. f/5.6 is when the Sigma starts getting good for non macro images.
Great 1:1 mag macro lens, just phenomenal.
Average medium telephoto lens, but usable.