P: Automatic lens correction for Sigma 14-24 dg dn leads to vignette overcorrection

[romansellier]

Hello, I would like to let you know that currently the lens profile of the Sigma 14-24 dg dn in Lightroom leads to a visible overcorrection of vignetting, especially at 14 or 15mm.
This happens when you just enable the automatic lens correction, with distortion and vignetting values set to standard values of 100.
I have attached an image taken at 14mm, the automatic lens correction in Lightroom being enabled.

One can clearly observe a white area including a thin white curve in the left and right corner of the image which is kind of disturbing.

Currently I am able to adjust this by significantly reducing the vignetting value to approximately 30-50, but it is only a workaround and it also depends what value for the distortion is set.

It would be very helpful if you could have a look at this and modify the lens correction profile of the Sigma 14-24 for Sony. 

Thanks.

[Rikk Flohr: Photography]

Roman, would you be willing to supply the raw file for this image so the team can test?

[Todd Shaner]

Rikk, here's a link to the original post in the LR Classic forum: https://community.adobe.com/t5/lightroom-classic/erroneous-lens-correction-for-sigma-14-24-dg-dn-in-...

[romansellier]

Hi Rikk,

sure. I just exported the unedited raw file as Jpeg in Lightroom and uploaded it here as the tool here does not allow me to upload ARW files or files bigger than 2mb.
If this is not helpful and you would need the ARW file, I could also send it via email, just let me know.
One thing about the photo I would like to mention is that I used a Haida filter holder with a reverse GND filter. The filter holder at 14mm seems to create very slim dark spots at the very edge of the photo...for example in the above right corner... just that you know. But it has nothing to do with the vignetting topic.

[romansellier]

Please find attached an additional photo at 14mm having had the same vignetting issue in Lightroom which I took without a filter holder. Hope that helps, 

[Rikk Flohr: Photography]

JPG files would be of no use. We would need a raw file that exhibits the issue.  You can post this on a Dropbox or similar service and just share a link if you like.

[romansellier]

Ok, no problem.
I just uploaded it on a Dropbox. Here is the link:

https://www.dropbox.com/s/g4r6xhj975zln9f/DSC04529.ARW?dl=0

I hope you can download it.

[Todd Shaner]

Using your DSC04529.ARW file I can confirm the vignetting over-correction in the extreme corners of the raw file at 14mm focal length. Interestingly the vignetting correction using the similar Sigma 14-24mm F2.8 DG HSM A018 Canon v2 lens profile looks a lot better. I have no idea how well that will work for other aperture and focal length settings, but you could give a try until Adobe can fix the Sigma 14-24mm F2.8 DG DN A019 lens profile.

[Rikk Flohr: Photography]

I've logged a bug with the Camera Raw team and attached the sample raw file. When fixed, this thread will be updated. 

[Todd Shaner]

Thanks Rikk!

[Rikk Flohr: Photography]

Updates to Camera Raw were released last night that address this issue. Please download the latest update via your Creative Cloud app and install. Please let us know if you continue seeing the issue after updating to 12.2.1. Thank you for your patience!

[scottn7461818]

The over compensation of lens vignetting has been improved but it is still overcompensated at 14mm. To be correct, the corners could have been darkened about another half stop.

[FeedbackCommunityMember]

I agree with Scott that in the corners it still slightly overcompensates (I did a test picture at 14mm).
But, it is significantly better than before.

[Todd Shaner]

This may be due to lens manufacturing differences.  Manufacturers often "revise" products to correct manufacturing issues.The lens sample Adobe used may be a different revision than the sample you purchased. Can you upload some ARW files shot at 14mm F 2.8 and F8. Shoot an evenly lit and even toned subject such as the side of a building or house. Composing the shot with a straight line object (roof line, siding line) aligned near the edge of the frame will allow checking distortion correction as well.

[scottn7461818]

Your attention to this issue is greatly appreciated Todd.
I've taken shots at f2.8 and f8 at 2 different focus points of uniformly lit blue sky and 3 focus distances of the north side of my house. Unfortunately the house shots show my diffuse shadow in the center. Hopefully they are still useful. 
The files are big, 10 images at about 40 MB each. What's the best way to upload them? I can email you a link to them in a Dropbox folder if you like.

[Todd Shaner]

You can copy the folder link on Dropbox and paste it in a reply here. On Dropbox click on the three-dots icon to the right of the folder and select Copy. Thank you!

[scottn7461818]

https://www.dropbox.com/sh/7nqs8gyzir...

[Todd Shaner]

OK, I can see the over-correction in the uploaded ARW files using the updated v2 profile. I suspect your lens sample is different than Adobe's. I discovered there was a firmware update issued 03/18/2020 for this lens that specifically states, "This firmware update improves the performance of the Vignetting Correction."


https://www.sigma-global.com/en/download/lenses/firmware/

https://www.sigma-global.com/en/download/lenses/firmware/popups/a019_14_24_28/index.html

https://www.sigma-global.com/en/download/lenses/firmware/a019_14_24_28/
Not sure how you would update the lens firmware with a Sony camera, but that may fix the issue.

[scottn7461818]

Thanks for finding that update. Only the L mount version was updated and the Sony E mount.
My lens was purchased from a high volume distributor in March so I assume it represents the latest production version. The serial number is 543964XX (I would rather not reveal the last 2 digits on a public forum). Was the Adobe sample an early version?

[Todd Shaner]

The Sigma 14-24mm F2.8 DG DN A019 lens is showing as first supported in LR 9.0, which was released November 2019. The lens itself was first available September 2019 so it's likely Adobe has an early production lens sample. Anything's possible including sample-to-sample manufacturing tolerances variation.

[scottn7461818]

I sent Sigma a note asking them why this is happening. Would you mind also following up with them? I'm obviously not the only one with this issue.
I find that I have to disable the LR lens profile to do the vignette correction but then I have to also manually do the distortion correction. If we don't get this resolved, can you release a lens profile with only the distortion correction?
For reference, I've attached 2 images taken of a uniform blue sky which were rendered using the newest (V2) LR profile.

[FeedbackCommunityMember]

@Rikk I’m seeing the same thing happening with my Sigma 24-70mm 2.8 ART on my Sony A7RIII. Happy to send my raw files in too. 

[Nick Rosen Photography]

Its almost 2024, why is this not fixed? I just purchased this lens and my lightroom is up to date but the profile still overcorrects vignetting.