Sigma 50mm f1.4 ART Focusing Problems

[Jeff2013]

I have a Sigma 35mm f1.4 ART lens that has been stellar, so I purchased the 50mm f1.4 ART.

On my D810(s), the new 50mm lens does not focus, consistently. When I attempt to calibrate the lens to the camera, the setting changes from +5 to +16, randomly. It is perfect on Live View, so I know that the optics are good.

I just assumed that I have a bad lens. Out of curiosity I did a Google search and found that others have had the same problem with this lens. One professional reviewer revealed that he had the same problem on a Canon body. Since the 35mm does not seem to have this problem, and one would expect that the same design would be incorporated on the 50mm which was introduced later, I assume that it is a manufacturing/QA problem.

The reason for my post, is that I am wondering if anyone else has had this problem and if it is something that Sigma can correct if I send it in to them. Do I do this, do an exchange with B&H or just return for a refund? My dilemma is that if I send it in to Sigma for repair, and they do not correct it, I will own an unusable lens, at that point.

I really love the optics on this lens and desire to somehow make it work. I have shot about 4 copies of the Nikon 50mm f1.4 and they are all soft (to my critical eye) at f1.4 - even with Live View, so I do not seem to have a lot of options. I shoot a lot of lenses and the only one I have shot that I can really trust at f1.4 is the Sigma 35mm f1.4 ART. I was hoping for the same experience with their 50mm version.

 

[WindwardHaole]

Fine tune may be effective for front or rear focusing issues but not for focusing inconsistency. No AF system produces 100% focusing accuracy or consistency, especially at f/1.4. Another Sigma 50 may or may not be a better match for your 810.

Some on this forum have mentioned AF inconsistency with Sigma lenses and as you state, "One professional reviewer revealed that he had the same problem on a Canon body".

Roger Cicala of LensRentals.com has several illuminating articles pertaining to auto focus accuracy and consistency. Aloha.

 

[HSway]

I have a Sigma 35mm f1.4 ART lens that has been stellar, so I purchased the 50mm f1.4 ART.

On my D810(s), the new 50mm lens does not focus, consistently. When I attempt to calibrate the lens to the camera, the setting changes from +5 to +16, randomly.

If this is what’s happening then the lens must be faulty. The question is whether it is just an incident or a wider issue for this relatively new camera.

This won’t help much but the lens on my d600 gives me unparalleled precision from MFD to infinity and I haven’t experienced any sort of inconsistency re the focus action and its accuracy.

If I was in your shoes I’d talk to Sigma whether their 50 Art is ready and fully updated for d810 describing them the problem that I’d double-check it exists, and take it from there. Report to this forum could be useful. I presume you did all the updates that might be necessary for your lens to work correctly via Sigma’s Dock.

It is perfect on Live View, so I know that the optics are good.

I just assumed that I have a bad lens. Out of curiosity I did a Google search and found that others have had the same problem with this lens. One professional reviewer revealed that he had the same problem on a Canon body. Since the 35mm does not seem to have this problem, and one would expect that the same design would be incorporated on the 50mm which was introduced later, I assume that it is a manufacturing/QA problem.

The reason for my post, is that I am wondering if anyone else has had this problem and if it is something that Sigma can correct if I send it in to them. Do I do this, do an exchange with B&H or just return for a refund? My dilemma is that if I send it in to Sigma for repair, and they do not correct it, I will own an unusable lens, at that point.

I really love the optics on this lens and desire to somehow make it work. I have shot about 4 copies of the Nikon 50mm f1.4 and they are all soft (to my critical eye) at f1.4 - even with Live View, so I do not seem to have a lot of options. I shoot a lot of lenses and the only one I have shot that I can really trust at f1.4 is the Sigma 35mm f1.4 ART. I was hoping for the same experience with their 50mm version.

--
Hynek

Sunwaysite

SunwaySite - Natural Landscape and Nature Photography

www.sunwaysite.com

 

[Jeff2013]

It is encouraging to hear that your lens works perfectly. I plugged mine into the Dock and it already has the latest firmware update. Thanks.

 

[HSway]

One more thing occurred me, check if this note has any relevance for you.

* Please update SIGMA Optimization Pro to Ver1.2.0 in addition to updating the SIGMA USB DOCK Firmware to Ver1.01 before using it with SIGMA 50mm F1.4 DG HSM.

http://www.sigma-global.com/download/en/detail/usb_dock.html



--
Hynek

Sunwaysite

SunwaySite - Natural Landscape and Nature Photography

www.sunwaysite.com

 

[snellius]

On my D810(s), the new 50mm lens does not focus, consistently. When I attempt to calibrate the lens to the camera, the setting changes from +5 to +16, randomly.

Do these changes occur in the same circumstances, or under varying circumstances? These variations depend on the aperture, distance and color.

 

[anotherMike]

Get the dock and calibrate using it, since it has 3 distance ranges. That solved most of my AF issues with my 50/1.4 Art.

One thing I *have* noticed, though, is that the 50 art does better with AF on "easy" AF targets versus "complex" AF targets. I have absolutely no idea why this is. An example of an easy target is a person in the studio wearing a sweater with contrasting black/white block patterns for the AF system to lock onto without thought, or the edge of a car in a parking lot. An example of a complex AF target might be a mixture of trees and fine branches where the arrangement of contrast objects/targets in the frame is harder to discern. I haven't done any exhaustive testing, but it seems that the Nikon pro glass does better with the latter than the Sigma 50 art. However, given I mostly shoot AF-S center sensor group in the studio or landscape, I've had no problems with focus once I got the dock and calibrated the lens that way (instead of through the body) and it's one seriously contrasty, sharp optic.

Good luck.

-m

 

[Island Golfer]

I find your comment interesting..."the 50 art does better with AF on "easy" AF targets versus "complex" AF targets." I found similar inconsistent results. However, I found that it occured when I attempted to lock onto "distant" targets, as opposed to "close" targets. Accordingly, I repeated the calibration process many times, using the Dock. What I ended up consluding was that, when the target is not filling the focus point rectangle, the AF does not lock on accurately. When I attempted distant focusing, my results were not nearly as sharp as when I filled the frame with a close object. As a consequence, I abandoned the Dock; and swtiched to the LenAlign/FocusTune system. On my Sigma 35mm ART, I ended up with a calibration of +14; and, the issue seems to have resolved itself.

 

[Jeff2013]

These are all very interesting comments. Thank you for your input.

It would be difficult to calibrate with the Dock since the focus varies from shot to shot, which my 35mm 1.4 ART does not do - it is dead-on each shot when shooting my LensCal target - or anything else. Dock calibration is also not a process I would look forward to. It took me forever to calibrate the 35mm f1.4 since some of the 4 points impact the other points. The good news is that it now focuses perfectly with zero calibration offset on multiple camera's.

I was hoping that Sigma had the answer to focusing consistency. My Nikon 85mm f1.4 only focuses accurately about 70% of the time on either my D810's or D800E. Any time I shoot at wide apertures I take multiple shots to make certain I have a keeper (I tried a friend's 85mm 1.4 and it was about the same).

 

[sgoldswo]

I have a Sigma 35mm f1.4 ART lens that has been stellar, so I purchased the 50mm f1.4 ART.

On my D810(s), the new 50mm lens does not focus, consistently. When I attempt to calibrate the lens to the camera, the setting changes from +5 to +16, randomly. It is perfect on Live View, so I know that the optics are good.

I just assumed that I have a bad lens. Out of curiosity I did a Google search and found that others have had the same problem with this lens. One professional reviewer revealed that he had the same problem on a Canon body. Since the 35mm does not seem to have this problem, and one would expect that the same design would be incorporated on the 50mm which was introduced later, I assume that it is a manufacturing/QA problem.

The reason for my post, is that I am wondering if anyone else has had this problem and if it is something that Sigma can correct if I send it in to them. Do I do this, do an exchange with B&H or just return for a refund? My dilemma is that if I send it in to Sigma for repair, and they do not correct it, I will own an unusable lens, at that point.

I really love the optics on this lens and desire to somehow make it work. I have shot about 4 copies of the Nikon 50mm f1.4 and they are all soft (to my critical eye) at f1.4 - even with Live View, so I do not seem to have a lot of options. I shoot a lot of lenses and the only one I have shot that I can really trust at f1.4 is the Sigma 35mm f1.4 ART. I was hoping for the same experience with their 50mm version.

To be honest, if you've tried calibrating using the dock (and for me this was as easy as focusing on a page of a newspaper at various distances), send it to Sigma, I think they promise to calibrate, repair or replace any lens that cannot focus following dock calibration.

 

[anotherMike]

Strangeness all around. My 35/1.4 Sigma art is dead money focus calibration wise, near or close, no dock nor finetune needed. And it's pretty good at more complex AF situations than the 50 art as well, at any distance. My 50 is definitely one schoolyard grade less good in AF capabilities compared to the 35, although again, for what I use it for, it's not at all a deal breaker.

-m

 

[Nephi]

I finally returned my 50 Art with a D810. I could not get the 50mm to focus consistently not matter what I tried. Other lens (from Nikon) were spot on.

I think perhaps its horrible quality control. I'd rather have a Nikon 50mm, nifty fifty, that focuses!

-Brian

 

[onasj]

I'm optimistic that this will largely solve your problem:

1) Get the Sigma USB dock (about $29)

2) Download the Sigma Optimization Pro software (free)

3) Attach your lens, download any firmware update for the lens, then input these settings (an educated guess):

Closest distance: +13

Next distance: +10

Next distance: +6

Farthest distance: +5

4) Test your lens's AF performance again. The slope of this curve should be about right; you can perfect the rest of the AF fine tuning using the in-body setting (e.g., if needed, set AF fine tune to -2 or +5, etc in your Nikon body).

 

[sgoldswo]

I'm optimistic that this will largely solve your problem:

1) Get the Sigma USB dock (about $29)

2) Download the Sigma Optimization Pro software (free)

3) Attach your lens, download any firmware update for the lens, then input these settings (an educated guess):

Closest distance: +13

Next distance: +10

Next distance: +6

Farthest distance: +5

4) Test your lens's AF performance again. The slope of this curve should be about right; you can perfect the rest of the AF fine tuning using the in-body setting (e.g., if needed, set AF fine tune to -2 or +5, etc in your Nikon body).

Unfortunately I have the dock and have calibrated the lens for focus. The problem is the focus motor, which doesn't seem to work on either my D750 or my D810. I spoke to Sigma UK, they agreed it sounded like it was defective and asked me to send it in.

 

[sgoldswo]

I finally returned my 50 Art with a D810. I could not get the 50mm to focus consistently not matter what I tried. Other lens (from Nikon) were spot on.

I think perhaps its horrible quality control. I'd rather have a Nikon 50mm, nifty fifty, that focuses!

-Brian

To be honest, any brand can have focus issues including Nikon (I must have returned about 4-5 Nikon lenses that would not focus accurately with my D800E). The build of the Art series lenses (despite my issue) is up there with the best pro grade zoom lenses for either canon or nikon.

Nikon should adopt the Sigma concept of the USB dock and allow differing adjustments at different focus distances.

 

[HSway]

Not sure what can be happening with the 50 Art on other bodies or in others’ instances but if I were to put the focus action of the 50 Art into perspective of some Nikon lens, the Sigma focuses on my D600 (in case someone is still using this ancient cameras) snappier and more reliable than Nikkor 70-200/4 VR.

Focus is sure and there is no hint of hesitation or hunting when shooting wide open. In low contrast and tricky light it will lock for a little longer than the zoom with the light levels decreasing. My only lens that probably feels more sure and locking for a tad longer is 24-70. I think I need to encourage the Sigma to lock where the 24-70 would still lock accurately. 24-70 may be a tad snappier. That's just a feeling. It’s possible that better focusing bodies would show me differences the D600 won’t.

24-70 is also my most reliable lens when focusing in LV and is rarely producing an error. 14-24 is less reliable. The 70-200/4 VR focus is dodgy in LV and needs to be re-checked carefully each time on D600, 50 Art is also better in that regard (feels like 14-24 or between 14-24 and 70-200/4) except that it’s barely functioning at largest apertures.

With fine tune I am doing on my lenses I have in practice run rarely into limits of what in-camera fine-tune method can do relative to the slight variances with distances or FL settings (we needed to sort this out with 24-120/4 and D90, though). That’s helped by the fact that I am always using my lenses in a certain way (most people do) and I can bias the adjustments certain way a bit, too. However, objectively, none of them is or ever was capable of precision the Sigma is, not to mention the customization that can be applied to the lens’ focusing accuracy in this regard.

--
Hynek

http://www.sunwaysite.com

 

[tiagophotos]

HI there

I ve the 50 Art and always work perfect with my old Nikon D3s and Nikon DF.

Now i have a Nikon D4S and surprise...i have the front focusing issue and is really really bad

i have to adjust +20 to work fine.

Thats really bad...

by the way, all nikon lenses works fine with the D4s

 

[cyuill2007]

I believe that some focusing inconsistencies are caused by overshooting being done one direction or the other due to the way the AF motor and focusing cams interact. Manually focusing the lens might result in more-accurate focusing on still subjects. I find this often works with a couple of lenses I own that are prone to mis-focusing under certain circumstances when using AF.

 

[RonYork]

I finally took time to use my USB dock to calibrate my Sigma lens.

What I found was that the Sigma lens AF tends to over-shoot, reverse toward a correct focus but overshoot again and then stop short of a really good final autofocus. This leads to front-focus error if approaching focus from a prior close-focus position and rear-focus error if approaching from more-distant focus. This prevents getting good focus for the 1st image using only remote trigger with mirror-up.

A much more consistent, on-target focus was achieved by using one manually-initiated pre-focus via back-button-focus (BBF) prior to using Remote Trigger w. Mirror Up. With a consistent AF, I was then able to establish focus calibration offsets.

I guess that I’ll need to make sure to double-tap my BBF when taking pictures manually or use the preparatory manual BBF step prior to any remote trigger shots. At least for the first shot from any new distance.

I don't think that there is anything wrong with the lens optics or sensor, so this should be something that Sigma could correct with a firmware update.

 

[Raymond Wave]

I had probs with 50 ART autofocus and finally got the USB dock as the local store was selling them for 19€.

I took an hour to make a rough calibration, nothing scientific, but wow, did it make a difference or what! I had previously shot with the AF finetune set at +16 in Nikon D610. I don't know if the D610 calculates different values on different distances based on this one value, but what I ended up with my 50ART were:

+16 / +7 / +4 / 0

So it was heavily front focusing at closer distances, but not that much at longer distances.

Maybe the fact that the AF seems to be inconsistent despite setting AF Finetune in camera is because it needs different tuning for different distances. So once you set the AF finetune for certain distance in camera, it still focuses off at different distance.

Based on this small calibration session I kind of feel like getting a new lens .