when I shot my first wedding I had the Sigma 30/1.4 on my old 50D! saved a ton of cash and got GREAT results. it was sharp @ 1.4 and cut glass @ 2.0
I am interested to know what your opion of the 30mm siggy on a crop vs the canon 50f1.4 on FF I find the canon 1.4 not as sharp wide open as I would like.
50mm has been my biggest disappointment changing from nikon as their 50mm f1.4 is a stellar piece of glass for the price.
I feel the canon f1.4 is good but compared to the sigma 85 (my new benchmark for a sharp lens) its not in the same class
I have experience with both the 30 and the 50 Sigs.
The 50D with the Sigma 30 1.4 impressed me so much that I wouldn't think of anything besides the Sigma 50 on a FF when I upgraded to the 5D2.
the Siggy 30 on the crop was FANTASTIC! the 50 on my 5D2 was a mess. I found it to not be as sharp the canon 50/1.8 I sold off. I tried three different lenses from Adorama (with MA'ing them all, shooting through the range of apertures) and finally decided I would not have the same luck as with the Sig 30. I also tried the Canon 50/1.4 and returned it because I found that the Zeiss 2/50 Makro best suited the performance, look and IQ I desired.
what I learned from it all was that there are very good optics out besides Canon L, sometimes saving you loads of cash, but I got the best I could get with the money I had and worked gigs the best I could.