Sigma 135mm

[Abitconfused]

I received a new Sigma 135mm and have taken about 200 pictures. So far I am disappointed. After reading many articles about how sharp the lens is, I discover how soft my lens is. While the 50mm art lens left me smitten, the 135mm art has left me holding a $1500 paperweight. I tested the lens using a Datacolor focus mechanism after mounting the 135mm on a Sigma USB docking station to check for firmware updates and calibration information. All focus points were dead on. I guess the lens (mounted on a Nikon D810) focuses well on a tripod when given a black and white target but often fails to focus given real world usage. I plan more tests but mark my calendar to be certain I return it before 30 days elapse! I will test using various focus point options today. So far, the responsiveness and sharpness of this lens have been a great disappointment. I contrast this with the much much cheaper Nikon 85mm f/1.8 which delights me first time and every time. Any advice will be appreciated. I dread paying the postal insurance for a return and hope for a cure but for now this lens seems sickly. Help!

[george013]

I received a new Sigma 135mm and have taken about 200 pictures. So far I am disappointed. After reading many articles about how sharp the lens is, I discover how soft my lens is. While the 50mm art lens left me smitten, the 135mm art has left me holding a $1500 paperweight. I tested the lens using a Datacolor focus mechanism after mounting the 135mm on a Sigma USB docking station to check for firmware updates and calibration information. All focus points were dead on. I guess the lens (mounted on a Nikon D810) focuses well on a tripod when given a black and white target but often fails to focus given real world usage. I plan more tests but mark my calendar to be certain I return it before 30 days elapse! I will test using various focus point options today. So far, the responsiveness and sharpness of this lens have been a great disappointment. I contrast this with the much much cheaper Nikon 85mm f/1.8 which delights me first time and every time. Any advice will be appreciated. I dread paying the postal insurance for a return and hope for a cure but for now this lens seems sickly. Help!

See it from the sunny side: it's good to have an paperweight.

You bought it on the internet I assume. If so, quite a risk you toke.
I just compared the Sigma 135 and the Nikon 85 on Opticallimits and the Sigma should be much sharper then the Nikon and is highly recommended.
http://www.opticallimits.com/canon_e...f18art?start=1
http://www.opticallimits.com/nikon_f...8518ff?start=1

I'm curious what's coming out here. But first show something.

George

[NorthernFocus]

Something certainly sounds amiss. Have you tested it on the tripod with targets other than the calibration target?

[Abitconfused]

I am now using the D810's 9-point autofocus set to continuous servo and the results seem greatly improved. However, the jury is demanding more evidence and transcripts of prior testamony about performance wide open.

[george013]

I am now using the D810's 9-point autofocus set to continuous servo and the results seem greatly improved. However, the jury is demanding more evidence and transcripts of prior testamony about performance wide open.

The amount of focus points and yes or no continuous is dealing with the way you're shooting, using the camera. Not important for a statical test image to check the performance of the lens.

George

[Abitconfused]

I tend to agree with you George. But in a number of low contrast situations with one focus point, I got no focus at all. My most recent test involved higher contrast objects. More work ahead.

[george013]

I tend to agree with you George. But in a number of low contrast situations with one focus point, I got no focus at all. My most recent test involved higher contrast objects. More work ahead.

You're testing the camera, not the lens.
Take a picture in normal light, just 1 single focus point, AF-S. And judge that. Then you're testing the lens. And from there on you can play further, other conditions, different aperture, different position in the frame etc..

George

[rpcrowe]

Although Sigma produces excellent quality lenses, there still seems to be some quality differences between individual copies of these lenses.

If I purchase a Sigma lens, I will purchase it from a dealer who will accept returns. Or better yet, I will pay the bit extra and purchase it from a local brick and mortar store where I can test it a bit before buying it. I will never purchase a used Sigma lens!

I am seriously considering the 16mm f/1.4 and 30mm f/1.4 Sigma lenses for my Sona A6500...

[Stagecoach]

Place it on a tripod in non glaring sun, focus it manually using Live View on a scene/object, at base ISO take three shots from wide open to closed down 2 stops.

Look and compare these three on your screen after undertaking basic capture sharpening and answer this, 'are these results acceptably sharp for my purposes'?

[Abitconfused]

OK, took a bunch more shots using 9-point focus and they are quite sharp. For whatever reason one point, single servo was not doing it for me. Not quite the five stars I see in some reviews but, a solid 4.5. Cannot see returning it at this point. Even starting to like it.

[Stagecoach]

OK, took a bunch more shots using 9-point focus and they are quite sharp. For whatever reason one point, single servo was not doing it for me.

To me that statement makes no sense Ed.

How can the 'Sharpness' that a lens can produce be affected by whatever focus method is chosen?

I believe you are incorrectly using the term and reference to 'Sharpness' instead of 'Focus Plane accuracy whilst auto focusing'.

[William W]

I received a new Sigma 135mm and have taken about 200 pictures. So far I am disappointed. After reading many articles about how sharp the lens is, I discover how soft my lens is.

What Grahame wrote.

Nowhere in your descriptions of your testing methods, have you been testing the Sharpness of the Lens.

WW

[xpatUSA]

What Grahame wrote.

Nowhere in your descriptions of your testing methods, have you been testing the Sharpness of the Lens.

WW

+1 to what y'all both wrote.

[Abitconfused]

My D810 has interfaced with every other lens effortlessly and produced very sharp reults. This includes a Signa 50 Art and a Sigma 24-35 Art. So no, the camera is not the issue. Sharpness is what you get not what you should get or hope to get.

[NorthernFocus]

So you got sharp results with the lens on a tripod, but not "real world" which was presumably hand held. And you are making comparisons between handheld results with a 135mm wide aperture lens vs a 50mm and 24-35mm wide aperture lenses. And are getting inconsistent results with the longer lens. And have received the advice you sought here on CiC from some well experienced individuals but that hasn't helped.

Been there done that. I've had very similar things happen in the past and ultimately I've always found the problem to be located behind the viewfinder. It's hard to root it out from back there. Definitely a lot more difficult to come to grips with than boxing the lens up and returning it.

[Abitconfused]

I photographed the calibration target with the camera on a tripod. The calibration target is a high contrast black and white square. I have had success with high contrast shots and very poor results with low contrast scenes. So I believe the tripod was not a determining factor but in lower contrast scenes my focus is random. An increased number of focus points seems to aid this issue.

[george013]

I photographed the calibration target with the camera on a tripod. The calibration target is a high contrast black and white square. I have had success with high contrast shots and very poor results with low contrast scenes. So I believe the tripod was not a determining factor but in lower contrast scenes my focus is random. An increased number of focus points seems to aid this issue.

Why don't you try what Graham advised, a manual focus using lightview. You overrule eventual focus problems with the camera, leaving left just the lens.
And what kind of a tripod do you have. I know the answer: a good one. But the lens is heavy and long sized
Show some examples, otherwise it's impossible to help you.
Good luck with the lens or the paperweight.

George

[Abitconfused]

Here is an image taken with the 135mm. Nothing is sharp because nothing is in focus. I have never seen this before using the D810. f/7.1, 1/50s, ISO: 100 focus point near center of flower bed.

[Abitconfused]

This image shows focus point using 134mm. F/2.8, 1/80, ISO: 100. While this may appear acceptable at first glance, we are talking about a lens reviewers describe as very sharp. This is not very sharp.

[NorthernFocus]

Ed, if you had provided some examples earlier on you may have saved yourself and the rest a bit of time. Based all the information you've provided it seems appropriate to refer you to the ages old rule that when shooting handheld (with a lens that has no VR) you keep your shutter speed at 1/focal length or faster. IOW on that lens 1/135s or faster. Or use a tripod and a hands-off shutter release.