3 out of 10 points and not recommendedGreat Sharpness and Contrast wide-open, 77mm filter thread for professional filters, great build quality, VERY smoothe bokehThe two copies I've tested have issues with my 5D (and other FF Canon cameras) when focusing beyond 10'
The issue with this lens, on both of the copies I've tested (and every independent individual who I've spoken to shooting this lens on full frame) is that it SEVERELY back focuses when you focus beyond 10' (3m). Granted I only occasionally use the lens beyond that range, but I should be able to without issue.reviewed July 26th, 2008 (purchased for $499)
It's really odd because the image is in focus in the viewfinder (I have split prism manual focus screen) and no matter how many times I refocus it back focuses by about 30-50cm at 3m.
When I focus any closer it is accurate and the image quality is stellar.
I've spoken to Sigma who were less than helpful (even condescending) but the distributor here in Perth (Western Australia) is being really helpful even though I imported the lens. My 5D has been checked and I have many large aperture lenses that have no issues with perfect autofocus at all ranges.
I have tested the lens on an EOS 40D and it doesn't seem to have any issues of note, so for those who never plan to go full frame this is a great lens I wouldn't hesitate to buy.
Given that it is an EX DG lens from Sigma and should work properly on a full-frame body I cannot recommend this lens to anyone using a full frame body and from a resale or upgrade perspective buying one at this stage in time makes little or no sense for any user.