I have to say that I love my Sigma 50mm Art. Well my second copy, with Sigma Doc and some patience. Most everyone interested in this lens is aware of the controversy surrounding it. Right? I found my experience to be a buying "process" (most unusual experience purchasing a lens at this cost...but for me it was worth it).
Some observations of the comments here:
1.This is a relatively expensive lens ($950), This is a large 50mm. It's not waterproof. It is not light (1.8 lbs). It has 13 elements for God sake...most people check specs and read reviews, for a purchase like this. Within the 1st 60sec. of looking into the lens I would think that if you want a small light lens..then..OBVIOUSLY this is not the lens for you. If you want a lens with weather sealing this is not the lens for you. If you want a cheap lens then this is not the lens for you. These things are more than obvious right away.
2. The iPhone comment should be deleted. It's just stupid.
3. Before I went on my Sigma Sojourn I was aware that this was not going to be a regular lens buying experience...but at my level of involvement in photography the lens had enough promises for image-making to jump in and give it a shot. (I owned a sigma 50mm EX and I own the Sigma 35mm Art...so I knew what I was in for with this purchase)
4. The lens copies are inconsistent with AF. I sent my first one back. It was ALL OVER THE PLACE with focus. I had a Sigma Doc. ...there was no correcting it. My second copy was much better out of the box and I was able to calibrate it and it works extremely well for me...right now...although...I have read reports that is could change over time...I will see. I knew going in that the lens experience was not going to be a normal one. I was on a quest for excellence in 50mm. Why bitch and moan...I know what I was getting into! LOL! (Its like dating!)
5. I owned a good copy of the Sigma 50mm EX f/1.4. I sold it to buy this. This is about twice the size...I knew that going in..I was looking for sharpness across the plane to the corners. There is no comparison in the two lenses. (although the size, and rendering of the EX makes it a very great lens for portraiture..its forgiving and I would say tons better than the Canon 50mm f1.8 and f1.4...and built way better as well...but again that is just my opinion and I had a very good copy...that I sold to a friend (gulp!) and he is VERY happy with it.)
So...this lens is interesting...and "for me" it has such a WOW factor...that it was kind of worth all the BS I went through to get a decently calibrated copy on the front of my 5D3. (time and money). The experience is not for everyone...but for the people that it is for ...their mouths can occasionally drop open when opening files in post...and goosebumps can run down your neck sometimes. That made it worthwhile for me. If you are looking for something exciting ...and you have some PATIENCE and some photography experience and ability...jump in ....I If not...I would advise you to stay away from this beast.
t's definitely not for everyone. its an interesting experience, though.