Help with evaluating Sigman 150-600mm Contemporary

[freixas]

Hi,

I just bought a Sigma 150-600mm Contemporary lens. I need to figure out if it is defective or just needs to be calibrated.

The lens has the latest firmware. I was shooting some bird photos and wound up with a lot of photos that looked slightly blurry. Here's one example:



I've circled some areas that look like there's a ghosting defect that doesn't seem to be just focus. For a while I thought maybe I had some motion blur (and I might), but the shutter speed was 1/1600. I've been shooting with a handheld Canon 100-400mm + 1.4x, which has nearly the same magnification, and never had problem with motion blur.

Well, I have the Sigma dock and the software for calibration, which seems to be a rather complex, time-consuming project. As I understand it, all this does is adjust the auto-focus; if I manually focus, the calibration is irrelevant.

So I went outside today, found a car parked a long ways away and tried several manually focused shots. The setup was:

• Live view focusing with 10x mag
• Shutter speed 1/1250
• Maximum aperture
  
• Camera on a tripod
• Optical image stabilization turned off
  
• Remote shutter release
• 10 second timer delay
• No wind
• Two shots for each attempt
• No AF adjustments in camera
• No AF adjustments to lenses (e.g. the lenses are as I received them)

The combinations I tried were:

• Canon EOS 80D + Sigma @ 600mm
• Canon EOS 80D + Canon @ 560mm (400mm x 1.4)
• Canon EOS 70D + Sigma @ 600mm

Here are the results. Each pair of shots is arranged vertically. Cameras and lenses change horizontally in the order above.



Despite lower magnification, the Canon 100-400mm + 1.4x result seems a lot sharper and detailed than the Sigma on either camera body, particularly the bottom middle shot. The bottom left shot seems to show some ghosting on the "F" and "d" of "Ford".

Can anyone confirm that:

• The manually focused shots using the procedure above are the best I'm going to get.
• No matter how I calibrate the lens, I'm not going to get anything better because calibration is only for autofocus.

Thanks for any help. If there's something else I should check or any other tests I can try, let me know.

 

[medic001918]

I shoot a Sigma 150-600 Sports and could never get it dialed in. I actually had Sigma calibrate it to my body and it made a world of difference. The multi step process is a challenge at best and they have software way more in depth than the dock.

$150 well spent and way more keepers.

 

[weepete]

Given your description that looks well off to me. Mind you I've found 1/1600th a bit slow at times but that's with fast moving subjects. With still subjects 1/800th usually is fine. Can you post an uncropped version of the bird and one of the car so we can get an idea of how much your cropping?

Even then, I don't think you should be getting this amount of blur and I'm swaying immeduatley towards falty.

The other thing to do is test the focus point for front/back focus, in other words shoot at some kind of target that's running away from you (like a wall or kerb of a sidewalk; I used a weed growing out of a path in my garden) with a shallow depth of field. Try some shots wide open, at f8 and f11.

 

[freixas]

Given your description that looks well off to me. Mind you I've found 1/1600th a bit slow at times but that's with fast moving subjects. With still subjects 1/800th usually is fine. Can you post an uncropped version of the bird and one of the car so we can get an idea of how much your cropping?

Even then, I don't think you should be getting this amount of blur and I'm swaying immediately towards faulty.

The other thing to do is test the focus point for front/back focus, in other words shoot at some kind of target that's running away from you (like a wall or kerb of a sidewalk; I used a weed growing out of a path in my garden) with a shallow depth of field. Try some shots wide open, at f8 and f11.

I won't post the full-size image, but here's a reduced size version without cropping, so you can see how it's cropped:



With my Canon 100-400mm + 1.4x, I would not get a blurry shot, even down at 1/1250 (but it's slightly lighter).

I'm leaning toward thinking the lens is defective. I pointed Sigma Support to this thread to see if they have any advice; I'm not sure if they'll bother with an email query, but it doesn't hurt to ask.

My earlier point/query is that I don't think front/back focus is relevant. That's for auto-focus. The second set of images was created without using auto-focus. If the lens cannot be focused manually using live view and 10x mag, I don't see how it could be focused automatically.

I went outside again, and I'm seeing consistent ghost images, strongly visible when white characters are on a dark background. I removed my UV filter, just in case that was an issue.

When working at lower focal lengths and/or closer distances, the lens seems super-sharp, even with auto-focus and no AF adjustments.

 

[Scott Whaley]

I have both the Contemporary 150-600 & the Sports lens. The quality of the Sports lens is much better than the Contemporary lens. My wife has the Canon 400 lens which is a better quality lens than the Sigma lenses. I have noticed a difference in the focus between my two Sigma lenses.

 

[Derrel]

Your photos of the Ford logo look bad to me. Not good, really not good. I'm unclear whether this is just the bare zoom lens or with the Lens used with a converter added. Regardless, the quality of these pictures is poor. Yesterday I was looking through an old hard drive and I was looking at some photos I took with the Nikon 200 mmf/2 VR and a used TC 201E , One of the finest lenses Nikon has ever made: but with the converter added, the results were rubbish . I returned the converter and used the lens for about a decade after that,and never had a single problem with it.

 

[freixas]

Your photos of the Ford logo look bad to me. Not good, really not good. I'm unclear whether this is just the bare zoom lens or with the Lens used with a converter added. Regardless, the quality of these pictures is poor. Yesterday I was looking through an old hard drive and I was looking at some photos I took with the Nikon 200 mmf/2 VR and a used TC 201E , One of the finest lenses Nikon has ever made: but with the converter added, the results were rubbish . I returned the converter and used the lens for about a decade after that,and never had a single problem with it.

The 1.4x extender was only used with the Canon 100-400mm. I haven't had any problems with this combination at any focal length, which is why the Sigma results were so surprising. In the bottom of the two Canon shots (the middle ones), I think I may have relied on auto-focus rather than eye. I should probably re-post a better set of comparisons; as usual, pressed for time, I used Irfanview as a short-cut and it smears the pixels around a bit once you scale things up too much. I need to do a 1:1 image comparison without interpolation.

Let me try that and re-post .

 

[freixas]

I have both the Contemporary 150-600 & the Sports lens. The quality of the Sports lens is much better than the Contemporary lens. My wife has the Canon 400 lens which is a better quality lens than the Sigma lenses. I have noticed a difference in the focus between my two Sigma lenses.

One of the members of this forum pointed me to a review where the reviewer found the contemporary to outperform the sports. The reviewer found this so unexpected, he had to re-check his results. That review, plus the cost and weight advantages of the sport led me to buy one. Unfortunately, I can't find that thread again or the link.

The sense I'm getting is that these lenses are quite variable in performance. Canon may have better quality control and consistency.

 

[freixas]

Here's a better comparison. These are all comparisons of manual focus using live view and a 10x magnification on the LCD of the camera.The results are somewhat dependent on my eyes.

Other than demosaicing and some noise reduction, no other alterations were done. Specifically, I added no sharpening. The image on my end is 1:1—what you see on your screen is out of my control.

I didn't feel comfortable posting some stranger's license plate number on the forum, but license plates make handy focus targets, so I left a few numbers. The distance to the car was approximately 400'.

The "ghosting" effect I've mentioned is most visible with white text on a dark background. I'll see if I can post some better examples, but it's most visible here in the "Ford" logo.

 

[weepete]

Thanks, shooting at these big focal lengths can be a bit different, small margins can make a difference. I do like to see if there is anything in sharp focus.

Keep the UV filter off for testing, it's just one more thing you can rule out. Better still, don't put it back on . I've always found autofocus better, the focus rings on these big zooms are a bit too sensitive for me.

But yeah, something looks funky to me and not as sharp as it should be, certainly in the centre. And that crop with the bird should be sharp.

 

[freixas]

A big thanks to everyone who tried to help, but I think this is a case of pilot error, although I haven't quite figured out how.

This morning, determined to check everything methodically, I decided to use remote viewing on my tablet to get the sharpest focus possible and then compare the results to the auto-focus. I also decided to shoot in the early morning to eliminate any heat distortion. The results were...surprising. The auto-focus was dead on except a little bit at the 400mm focal length and I saw no sign of the ghosting/double-exposure of the highlights that I captured yesterday. Maybe it really was all heat haze, although I thought that would create distortion and not ghost images. I used the USB hub to adjust only the 400mm/infinity setting.

Then I went to a local nature park and got photos of herons, grebes and other birds. No problems—not even with handheld shots of birds in flight. Things look sharp. I am totally puzzled because I have clearly out-of-focus images shot with all the same settings (and air temperatures) from just a few days—except that this time I had removed the UV filter. For my own curiosity, I will put it back on and see if things screw up again; otherwise, I am baffled.

I've posted shots in this thread.