Canon 50mm 1.2 vs sigma 50mm 1.4: older expensive l-glass, or newer future tech

[bchernicoff]

I owned the Sigma and really liked it optically, but wasn't happy with the focusing speed (5D Mk II). I sold it for the Canon 1.4 and am very happy. Here's a shot taken with the Canon on my 5D MK III in natural light at f/2.

[hbeevers]

I've got the sigma 50. Tried the canon 50 but hated it, if i'm spending more than the 50 1.8 (which is brilliant for the price) then I want a sharper lens with gorgeous bokeh and very importantly i want build quality. The main fault with the 1.8 is the build quality, the 1.4 doesn't correct this but the sigma and 1.2 do.

As for which to get, i'd say go for the sigma. The canon 1.2 is lovely but it's just not THAT much better than the sigma, especially for focus speed/accuracy.

[bchernicoff]

This might be a good place for me to bring up something I have often wondered about. Do manufacturers ever slip in unannounced updates to lenses? I have to assume they do even if it's only firmware. Is there a way to tell? I like the idea of Sigma's newly announced usb dock lens cap for firmware updating lenses.

Any chance a brand new Sigma 50 would have more accurate or faster focusing than one from a few years ago?

[drmikeinpdx]

I've had a Sigma 50 1.4 for about two years, which I bought primarily to use with my 5D classic as a large-aperture portrait lens.  It was plenty sharp enough for me when the focus was accurate.  Unfortunately, with the notoriously weak autofocus of the 5D classic, a fairly high percentage of my large-aperture portrait shots were out of focus.

I got a 5D Mark III last week and the first lens to undergo focus testing in my studio was that Sigma 50.  I was relieved to see that it now focuses faster and more consistently.  I think I dialed in +2 on the micro-adjust.  Images were pretty sharp wide open and extremely sharp at f2.0.

I then tested my Canon 85mm 1.8 and my Canon 100mm 2.0.  They did not need any micro-adjustment, but I did notice quite a bit of chromatic abberation wide open just in front of and behind the point of focus.  Lightroom fixed it pretty easily and it went away when I stopped down two stops, but I did buy these lenses to shoot wide open, so I'll have to keep it in mind.  I was shooting RAW at the time.  I wonder if the Mark III would correct that if I selected JPG?

Anyway, whenever we talk about the autofocus performance of a particular lens, (fast, slow, accurate or innacurate) I think we should specify which camera body we are using it on.

[bchernicoff]

I got a 5D Mark III last week and the first lens to undergo focus testing in my studio was that Sigma 50.  I was relieved to see that it now focuses faster and more consistently.  I think I dialed in +2 on the micro-adjust.  Images were pretty sharp wide open and extremely sharp at f2.0.

It's statements like this that make me wish I hadn't sold mine before my Mk III came. I really would like to see what difference the body made.

[bchernicoff]

Roger at lens rentals has opinions on these lenses that you might find useful. Apparently both the Canon 1.2 and Sigma have AF quirks that fall into repeatable patterns.

See Roger's Take:

Canon 50mm 1.4 : http://www.lensrentals.com/rent/canon/lenses/normal-range/canon-50mm-f1.4
Canon 50mm 1.2L : http://www.lensrentals.com/rent/canon/lenses/normal-range/canon-50mm-f1.2l
Sigma 50mm 1.4 : http://www.lensrentals.com/rent/canon/lenses/normal-range/sigma-50mm-f1.4-dg-hsm-for-canon