I've got one for review purposes right now, and I dislike it so much that I'm having a hard time doing the review. So much green fringing, and I can't seem to get it to nail focus even after multiple AFMAs.
It may not help it that I am also reviewing the Zeiss APO Sonnar T 2/135mm ZE and it is pretty close to optical perfection (and should be for a manual only focus lens that costs nearly $2500!)
Dustin I feel your pain...but I must have the only good copy of the Sigma 50mm Classic...Mine is spot on with AF, and I really like the rendering of the lens..yeah...it needs some defringing in LR...but hey..when I bought that lens I was looking at the 50mm f/1.8 and the 50mm f/1.4 and they are both basically junk lenses...I think the results are as good (to me) as I see being rendered by the 50mm f/1.2L. I got my copy for about $400...Peanuts compared to the "L". It is a lens that I do not use that often...but when you need it, you need it!!!! The bokeh is great at 1.4. I am using the lens on a 5DIII with no Micro Focus Adjust. It is set to zero.
Even Roger at Lens Rentals (who I hold as an incredibly valuable source of info regarding any lens) winces at the issues of the Sigma classic...but he basically likes and rents the lens.....According to him is the lens is misfocusing you cannot micro adjust it as the lens front focuses close and then thee lens back focuses at medium distances (or vice versa, I cannot remember) so if you tune the camera to focus it makes it better in one area and makes it worse in the other plane of focus....
I am not a measurebator or FoCal guy, etc...I like to take photos, not sit around doing tests...I had a reason this weekend to double check the focusing with my copy and it just seems to nail the focus whereever I put my focus point. Close far, it does not matter. A LOT of people sure have cursed this lens over the years ....so you are not alone.
I am thinking about selling mine (which will be a trip I know...if I sell it to a FoCal guy it will be a drag!!! LOL!) to buy the new Sigma 50mm...but I am waiting for your review...so GIVE IT UP...will ya!!!!!! LOL!
Oh...and the price has gone up on a new 50mm classic....if you can find one they are selling for $500 again. B&H was out of stock for months...but they have more in stock now. Its only for the brave of heart!!!!! LOL!