28mm f/1.8 Canon or Sigma

Anyone own both of these, switch from one to the other perhaps? I need a cheap fast 28mm, don't need or want an L. I've owned the Sigma EX 50/1.4 for some time now and love it. Thinking the Sigma, at $289 might be comparable to the Canon as far as IQ goes...I know the Sigma is not HSM and the Canon is USM, so it's faster and quieter, but are they both accurate?
Are they similar wide open as far as sharpness and CA and such?
Thanks.

OK, bump....anyone own the Sigma?

i used to own the sigma it but sold it. i loved the close focusing and the build/hood are fantastic. i didn't notice a lot of CA with the sigma but the canon 28 supposedly has CA problems wide open. there are reports of focusing issues with the sigma but mine was fine - a little noisy but no complaints. i found the sigma a little soft but nothing too serious. i would have liked it to be a little smaller like the canon and the focus could be a little faster and quieter like the canon but overall the sigma was an excellent purchase for the price. it's a nice lens but from what i've read the canon 28 is much better. i do regret selling the sigma since it was so cheap but i am planning to add the canon to my lineup eventually.

why do people require so much emphasis on AF being accurate? they're wide angle primes..

Kajuah wrote in post #7576097
why do people require so much emphasis on AF being accurate? they're wide angle primes..

really? don't you think it's a must when using thin DOFs?

not at all, I think manual focus is much more accurate and reliable especially when using thin DOF's..for a wide angle, though, you're not likely going to be using very thin DOFs. A macro lens you will be, a telephoto you will be, but a wide angle is used for landscapes and shots you generally have high F numbers to take. Maybe portraits in certain situations. But then you're most likely going to need a higher F number, anyway. Shots of the sky and astrophotography is where the 28 1.8 shine; don't need a powerful AF engine for those.

MF is more accurate even on the most advanced lenses if you're fast, granted not saying AF is useless in all instances, you just tend to get more hits than misses when you use MF rather than emphasize on a lens' AF.

i never really did use MF very much but maybe i should try it more often. i mainly use the WA primes for people/event/concert photography so, for me, accurate/fast AF is essential.

anyways, fwiw, if the OP is looking to use the lens like i used it then i would definitely recommend the canon (even though i havent used it), because it's smaller, lighter, faster, quiet and sharp compared to the sigma.

Thanks, good to know....Why do I want AF to be accurate? Because I use it and don't MF unless I'm shooting macro which is seldom, it will also be my walkaround for my current crop body which gives me about a 45mm view.....not really wide in my book

oh right i should have mentioned my 28 was on the 40d

and since you want it for walkaround... i found the sigma just a little cumbersome on the 40d for a walkaround. the build and size of the canon 28 is supposedly a lot like the 50 1.4 which i find a lot better than the sigma as a walkaround (i use the 50 on FF as walkaround). not sure if it matters to you as much as it did to me but i'm sure the canon 28 will balance and feel better as a walkaround than the sigma on your crop.

I own the 28 f1.8 USM and AF is accurate even at f1.8 The only complain I have is purple fringing at f1.8 but stop down to f2 and its very minimal only when pixel peeping.

After a few troubles with Tamron and Sigma lenses' AF accuracy, I thought I'll just stick with Canon lenses.

Kajuah wrote in post #7576097
why do people require so much emphasis on AF being accurate? they're wide angle primes..

what?

I use wide angle for shooting bands in very dim bars. Even with thin DOF I need it to be accurate. I don't want to shoot a face and get the amp behind them in focus.

As for the 28 I've heard many good things about it. I've been thinking of getting either that or the 35 again, I'm just not sure how much I want to spend yet. As for sigma after my experiences with the 30 I'll never go back. I know I can't judge all of the sigma lenses by a few horrible copies of the 30, but I'd rather just stick with canon for now.

gardengirl13 wrote in post #7580063
what?

I use wide angle for shooting bands in very dim bars. Even with thin DOF I need it to be accurate. I don't want to shoot a face and get the amp behind them in focus.

As for the 28 I've heard many good things about it. I've been thinking of getting either that or the 35 again, I'm just not sure how much I want to spend yet. As for sigma after my experiences with the 30 I'll never go back. I know I can't judge all of the sigma lenses by a few horrible copies of the 30, but I'd rather just stick with canon for now.

Yeah, that's the way I felt about 3rd party lenses in general before I got the EX 50/1.4, was just dissapointed too many times.

strobe monkey wrote in post #7578842
(1) I own the 28 f1.8 USM and AF is accurate even at f1.8; (2) The only complain I have is purple fringing at f1.8 but stop down to f2 and its very minimal only when pixel peeping.

i concur on both points.

I've been thinking of that one too, but for now my very sharpe little nifty fifty is working just fine. But if anything ever happens to it I would be curious to try the sigma 50, unless canon upgrades the 50 1.4.