Keeper rate: Sigma 35 Art vs Canon 24-70ii

I bought the sigma 35 a year back, after reading many reviews that the AF is far more consistent than it was in the past.

fast forward to today, i still get quite a bit of OOF shots with the sigma as compared to my canon 24-70ii. The keeper rate is probably around 70% vs 95% (if we only take into account the aspect of nailed focus).

does anyone else face the same sentiments as i do? sure, it's not an apple to apple comparison, but i have this feeling that even shooting the sigma @ 2.8 doesn't give me consistent AF as compared to the canon.

all comments welcome!

I dunno, the question in my mind is more along the lines of how is the keeper rate vs the canon 35mm f1.4.....

Sigma still does have some AF issues but they are worlds worlds better. Like my 50-500 OS in servo mode sort of constantly moves a little if i *don't* (edit) dramatically tweak the settings on the 5d3. 100-400 has no such issue. On the 6d the 50-500's AF is absolutely rock solid perfect always (the 100-400 works well too, but no better than the sigma.. and the sig is world better than the 300 f4l is i rented, af wise, go figure... i bet the opposite would be true on the 5d3 though...AF, Ahhh! the sooner it's all on sensor and perfectly aligned the better!).

From a friend that has used the 35mm art a lot: it works great except it sometimes misses when you get farther away. So up close no problems. Infinity (or perhaps across a long room at a wedding party--maybe less accurate). That's what I've been told. No personal experience. They prefer the 35mm f2 IS over it and the 35L both. Something to think about. For optics the sigma has it though.

I have about the same keeper rate from my 35A as my Canon lenses.

If you want to compare them, take some photos at f/2.8 with both lenses...

Titi

If you're using the 24-70ii with a 5d3 or 1DX then you're getting the advantage of the rotation detector in the newer Canon lenses. The AF with those bodies and the newer lenses really is amazingly consistent.

Roughly same but then I use my sigma lot more than 24-70mm f2.8 II and sigma is @f1.4 most of the time. Camera 5dmk3.

the.forumer wrote in post #17018111
I bought the sigma 35 a year back, after reading many reviews that the AF is far more consistent than it was in the past.

fast forward to today, i still get quite a bit of OOF shots with the sigma as compared to my canon 24-70ii. The keeper rate is probably around 70% vs 95% (if we only take into account the aspect of nailed focus).

does anyone else face the same sentiments as i do? sure, it's not an apple to apple comparison, but i have this feeling that even shooting the sigma @ 2.8 doesn't give me consistent AF as compared to the canon.

all comments welcome!

Heya,

Remove the "feeling" and simply do a real world test.

Set the Sigma to F2.8, same settings for everything as the Canon lens. Shoot at the same focal length, 35mm. Set up on a tripod. Set up a dummy some where to test shoot. Nothing moves. Use a remote shutter release. Do a series of 100 shots on each lens. Then see which nails focus, and which does not. Count them up.

I have a feeling that you're just missing focus at F1.4 handheld. And if you're missing at F2.8, it's more due to your handholding technique or typical body sway than anything.

Very best,

I use the Sigma 35 very much and I need to say that the keeper rate (AF) is very high. I don't see a lot of missed focus etc.

Bottom line, I'm very happy with this lens!

I don't have the 24-70, but my keeper rate with the Sigma 35 is very high; I have no problems with AF in any light.

I'm wondering if it differs between bodies with this lens; I'm using a 5DIII.

Relatively wide lenses with wide apertures is about the biggest challenge you can give an AF system, so I would expect your keeper rate to be a little lower with any 35 f/1.4 than with the gold standard 24-70 f/2.8.

Using them side by side, in my experience the Sigma 35A lags slightly behind the 35L in keeper rate (particularly in low indoor lighting)...but overall I "feel" like it is very much in the same league as the Canon L series.

I recommend using only cross type AF points if you're using a 5D3.

LV Moose wrote in post #17018619
I'm wondering if it differs between bodies with this lens; I'm using a 5DIII.

Absolutely it matters.

In challenging light, the 6D compared to say... the 5DII, you'd see quite a difference in keeper rates of nailing focus.

Very best,

i dont own the sigma 35 but my experience with the sigma 50mm non-art along with the canon 50mm 1.8 is that even after calibration, @1.4 the sigma doesn't achieve perfect focus most of the time. The keeper rate is much higher on @F2 on the other hand.

When shooting high contrast targets on a tripod using phase-detect AF, you can expect to find slight hints of purple/green fringing for most shots. Sure, its in focus...but not in PERFECT focus.
In live view contrast-detect AF, the purple/green fringing is not present and you can see a slight increase in sharpness.

If i am very critical on focus, I prefer to use MF @f1.4. Phase-detect AF @ F2 is fine though.

I don't notice this problem on the canon 50mm and can confidently shoot wide-open with phase detection AF. Same goes for my canon 70-200 f2.8 IS mk1

^ how does fringing have anything to do with how you focus?

LV Moose wrote in post #17018795
^ how does fringing have anything to do with how you focus?

anything out of focus will exhibit fringing in high contrast areas.

zarray wrote in post #17018806
anything out of focus will exhibit fringing in high contrast areas.

Yes. Okay, maybe I misunderstood what you were saying. As long as you get the image in focus (or out of focus) the way you achieved focus (or misfocus) has nothing to do with the amount of fringing.