tracer bullet wrote in post #1992670
You have / have had each of the 3 lenses I'm considering right now. I've been wanting one for several months now, just haven't found a good price on ebay yet.
Since you've tried all 3, how did you settle on the Sigma? Why didn't you keep the Canon or Tokina?
I sold the toke b/c I got a 1D MII N and didn't want any cropped sensor lenses, then I changed my mind and got a 30D and a siggie. Yes, I'm a recovering GASaholic (Gear Acquisition Syndrome). My buddy has the Canon so I've tried that as well.
Optically, they are all very good. So unless your default printing size is above 12x18, sharpness is a moot point. The toke is really built nice, like a tank with a felt lined hood like a L lens and a pretty fast motor. The constant f4 is nice too. No FTM MF ring though. It's color is a bit cooler than the Canon. There is a bit of vingetting at 12mm with a regular CPL but the hood is big enough for you to reach in and rotate the filter though. The only optical issue is the CA at the wide end and the 12mm as there is a noticable diff. between 12 and 10.
Canon is a very nice lens with fastest AF, but it's the money factor. Too much dough and you have to fork out another $40 for a hood? No way. It also feels the cheapest compared to the other two.
I ended up with the Sig b/c I wanted the 10mm wide, it's relatively fast enough at f4-5.6, although the variable aperature is a bit of a pain. It feels very good with a very quiet AF motor and FTM MF ring. The hood is very small that you cannot rotate the CPL with the hood off, but no vingetting with a full thickness CPL, which is nice. The color is a bit warmer than the Canon. So I went with the Sigma b/c of the price, optics, quiet/fast AF, FTM MF ring, and the 10mm wide. Afterall, if you are gonna get an "ultra" wide, why settle for 12mm when 10mm is available without any sacrifices?