Sigma 50mm f1.4 EX DG HSM....are they any good?

[brandsteve]

The canon 1.2 was too much for our budget.  We tried out the Canon 1.4 and with the 7D found the autofocus to be rather slow.  It was a frustrating lens to use.   We then tried the Sigma 1.4 and wow what a lens.   

I've heard the stop down issues with the Sigma 1.4 are mostly an issue on full frame cameras.   We've had great results with ours.  My wife has put her L zooms in the drawer and rarely takes them out now.

[drmikeinpdx]

While I am certain that some lenses focus more reliably or faster than others, I feel that the whole DSLR autofocus system that is currently in use is loaded with potential problems and really needs to be replaced with something that will inherently compensate for the imperfect tolerances of both lenses and cameras.

My main camera is a 5D classic, which had a severe front focus problem when I bought it used.  Canon fixed it for $200 and it worked fine with Canon lenses most of the time.  After about a year, I upgraded from a Nifty Fifty to a Sigma 50mm 1.4 lens.

I found that the Sigma would front focus about 3-4 inches at full body portrait distance, but I liked the image quality enough that I learned to compensate by focusing on the model's ear instead of the eye.  No micro-adjust on the 5D classic of course.  The Sigma was my main lens for about a year.

Several months ago I bought a 7D and tried the Sigma on it, thinking that I would just dial in some micro-adjust.  Doing some really precise testing, I did notice the focus shift with aperture changes, but it wasn't terrible.  I decided to set the micro-adjust for the very slight back focus at f1.4 and ended up with only -1 compensation.  Not bad, but obviously different than what I was used to with my 5D. 

I put the Sigma away around that time, because both the 5D and 7D were now sporting zoom lenses.  (Crazy focus stories on those lenses as well.)

Last week, while at a group glamour photoshoot, we were going to shoot with available light and I thought f1.4 would be perfect.  I got out my Sigma and did some test shots with the 5D to see where it was focusing so that I could compensate. 

I used a chess set in a "sun room" with large windows as my target and focused on the top of the white King.  Magnifying the image on the LCD screen as much as possible, I was surprised to see that the Sigma was now focusing perfectly at f1.4.   I shot two more times to verify and got the same results.  I'll post one of these shots with a crop of the chess set.  These are almost direct from RAW and my software applies minimal sharpening.  Normally you would add a lot more.

If I had it to do over again, I'd probably buy the Canon 1.4 which at the time was $150 less, but I have enjoyed the looks I get from other photographers when they see that huge Sigma! 

But my real point here is that focus performance is almost completely unpredictable due to the trouble prone system currently in use.  It makes perfect sense to me that people on forums like this disagree vehemently about how well a particular lens or camera focuses.  I think the system must have been designed in an era when it seemed that small aperture zooms would completely take over the SLR world.  Those of us who choose large aperture primes are stuck with a lot of frustration.

Mike in Portland, OR

[willrobb]

canon 50mm 1.2L were dismissed on poor build quality/cost.)

Poor build quality?

Typo error on my part, poor build quality for the 1.8, the build quality of the 1.2L is awesome.

[niccyboy]

Ahhh i see...

good luck with the canon 1.4!

[Craig Richardson]

Might be a bit late to join the party here, but my brand new Sigma 50mm 1.4 is currently "in the shop".  I had to take it over to Gentec International for calibration.  Turns out they are located in Markham, Ontario about 10 mins away from my house, I don't think they get very many drop-ins but were very nice and immediately confirmed my front focusing issue on their own rebel body.  I hope to get it back by the end of the week.

[Mt Spokane Photography]

Since you mentioned that he has a 5D MK II, I'd say go Canon.  The Sigma is a tad sharper on a crop, but the Canon is better on Full frame. 

A lot of responders have crop cameras, and will like it better.

[skitron]

I've had two of the Sigma 50 1.4 and almost sent the second back as well. But then I tried shooting it without the B+H MRC UV and it focused just fine. So been using it ever since with no filter. The hit rate is not as good as my 100 L, but it hits in the low 90%s for me. Getting some very nice shots with it and glad I kept the second one. Very little focus shift on mine and that was the first thing I checked since it's all you see on the net about this lens.

[carlc]

I have the Sigma 50mm f1.4 EX DG HSM on a Canon 7D and love it.  A little more expensive than the Canon f1.4 but it is built like a tank.  Great balance on a 7D, fast and accurate focus for me.  I would buy another one if anything happens to this one.  I am still learning some of the vast capabilities of this lens but it just kills low light challenges.  Also own a Canon 24-105 and 10-22.  Just waiting for the new 24-70 (if it has IS I will purchase).  Also rented the new (II) Canon 70-200 and it is on my wish list right behind the 24-70.

I should note that I never used the Canon f1.4, just went with the Sigma f1.4 based on reviews and I don't regret it for a second.  It will be on my 7D throughout Christmas.   

[Craig Richardson]

Might be a bit late to join the party here, but my brand new Sigma 50mm 1.4 is currently "in the shop".  I had to take it over to Gentec International for calibration.  Turns out they are located in Markham, Ontario about 10 mins away from my house, I don't think they get very many drop-ins but were very nice and immediately confirmed my front focusing issue on their own rebel body.  I hope to get it back by the end of the week.

Just a quick update, my Sigma was reprogrammed by Gentec and it is nailing focus now from a few quick tests I have run at close range.

EDIT: I was still having unpredictable focus shift problems until I read Skitron's post and removed my B+H UV filter and now close focus is good again.  I really hope the far focus is fixed too because it was back focusing today at a distance.

EDIT 2: Lens is completely unpredictable, would not recommend at this point.

[skitron]

EDIT 2: Lens is completely unpredictable, would not recommend at this point.

One thing I noticed about mine was if the camera is not steady (i.e. good handhold technique) I will often get both motion blur and OOF. It's as if the AF can't deal with much camera motion and still do its job. Only an issue at low aperture values.

Another thing I'm going to try even though I'm having good luck with this lens is shooting in AI servo mode when at low aperture values due to the very thin DOF. Several folks are recommending this in the Canon vs Sigma 85mm thread and it makes alot of sense. May be worth a try for you.

[Craig Richardson]

EDIT 2: Lens is completely unpredictable, would not recommend at this point.

One thing I noticed about mine was if the camera is not steady (i.e. good handhold technique) I will often get both motion blur and OOF. It's as if the AF can't deal with much camera motion and still do its job. Only an issue at low aperture values.

Another thing I'm going to try even though I'm having good luck with this lens is shooting in AI servo mode when at low aperture values due to the very thin DOF. Several folks are recommending this in the Canon vs Sigma 85mm thread and it makes alot of sense. May be worth a try for you.

I can't get my head around how a lens can be so out of focus (like -11 needed to take a picture of the CN Tower because of back focus) but the phase detection can declare it in focus.   What exactly did Sigma have to do to reverse engineer this focusing system?   I also don't understand how this switches to front focus under 10 feet... or why when I use high quality B+H UV, CPOL, or ND filters the focus problems sometimes reverse themselves.  Gentec has alot of work cut out for them when I bring this thing back again to them.

EDIT: I have done some light reading and came up with this gem:

When you half-press the shutter release (or the * button, if you've used the custom function to move focusing control there), the activated AF sensor "looks" at the image projected by the lens from two different directions (each line of pixels in the array looks from the opposite direction of the other) and identifies the phase difference of the light from each direction. In one "look," it calculates the distance and direction the lens must be moved to cancel the phase differences. It then commands the lens to move the appropriate distance and direction and stops. It does not "hunt" for a best focus, nor does it take a second look after the lens has moved (it is an "open loop" system).

If the starting point is so far out of focus that the sensor can't identify a phase difference, the camera racks the lens once forward and once backward to find a detectable difference. If it can't find a detectable difference during that motion, it stops.

Source: http://www.zen20934.zen.co.uk/photography/Canon%20AF%20System.htm

So what basically happens is that when the camera gives the instruction to the lens to move, the Sigma lens understands that it is a move order but does not move precisely enough.  Because there is no second check on focus, errors are left uncorrected.  This is why AI-SERVO seems to work better because the camera is constantly looking at the focus and making corrections, it creates a closed loop and errors eventually reach zero, or so you would think! 

This also explains the strange pulsing behavior of this lens in servo mode because the camera is expecting the lens to nail focus after the first move order, but it doesn't so therefore the camera thinks the subject must have moved so it calculates a delta for subject shift and comes up with a move solution and tells the lens to execute, which it does but the lens screws up again, and so on and so on.

Another update: AI Servo works really well.

[skitron]

Another update: AI Servo works really well.

That's good to see. I'm having pretty good luck out of mine but this looks like it should make the percentages even better, plus maybe it works using a filter.

BTW, I get the same "pulsing" sensation with my 100 L when in servo, so it's not a Sigma specific thing. It's a bit smoother but definitely there.

[smirkypants]

I have the lens and I like it. Don't love to bits, but like. But this post isn't about that.

Here's something to consider. I do almost exclusively outdoor shooting and have several expensive ND filters to be able to hit the max 250 flash shutter sync speed wide open (yes, I know, I should have bought a variable to begin with, but didn't), plus a graduated ND and a polarizer. These were all 77mm because I own a 70-200/2.8, a 17-55/2.8 and a 100-400. I have other sized filters, but my big money is in the 77s.

So I was going back and forth on the Canon 1.4 vs. Canon 1.2 vs Sigma 1.4 when it occurred to me that the Canons use 58mm and 72mm, respectively and the Sigma 77mm. To be honest with you, this made it an easy decision for me. First, I didn't have to buy a bunch of new filters that may have doubled the cost of the lens, and second I didn't need to add weight to my camera bag.

It's something to consider.

[whatta]

Here's something to consider. I do almost exclusively outdoor shooting and have several expensive ND filters to be able to hit the max 250 flash shutter sync speed wide open

could you show me few examples (pictures) of this technique? I wonder what is it for.  Thanks a lot.

[catz]

I have Sigma 50 mm 1.4 EX DG with 5D mark II.

- It is a good lens (I am going to keep it)
- However, it is not perfect:
- All Sigmas have a bit less neutral color balance compared to Canon L. The 50 mm Sigma is no exception. It must be lens coating or something, but similarly than 12-24 EX DG, this 50 mm has a slight tint into yellowish.
- There is some chromatic aberration on out of focus areas, more than for example in Canon 70-200 2.8 L IS USM.

I have sort of stated to love the neutral (non-tinted) look of Canon L, and I think the only lens I would possibly trade this Sigma would be Canon 50 mm 1.2L. It is very expensive so not going to happen anytime soon.

I love the 50 mm on full frame since it is useful as general purpose lens. On crop sensor I could find hardly use for the lens except for maybe portraits. I can do even landscapes with this on full frame.

I have tried the lens on 60D but I was dissatisfied with the field of view.

For crop sensor a good alternative lens for giving 50 mm field of view is Samyang 35 mm F1.4. It has similar performance than the Sigma and has the best manual focus ring of the lenses I have used. It has also build quality and robustness comparable to a big Canon L. I don't think the 50 mm Sigma is a good choice for crop sensor unless you are looking 75 mm field of view (which incidentally I get out of my 70-200 on full frame which has more neutral color balance IMHO).