The problem of the vignette during image postprocessing

[lordsvarogofmax]

Maybe this question has already been asked, but I can't fix the resulting vignette in the image after processing the dng sequence in Davinci Resolve. When interpreting the color space in Rec.709 and the sRGB gamut, there is a constant darkening on the sides of the frame.

[mirsadm]

Can you send me the DNG? The camera reports a shading map to fix the corners of the lens that are darker. They get saved in the DNG automatically. You shouldn't need to fix it manually

[lordsvarogofmax]

Yes, of course. Here is this dng file, for example

https://drive.google.com/file/d/1M8lHTe5x1ciPaffw05fau2VV0sCa2oJ1/view?usp=sharing

[ghost]

It looks good in Photoshop and Google Drive preview. But DaVinci shows vignette in this DNG.

[lordsvarogofmax]

Maybe there is some special rule of interpretation of the color profile in Davinci?

[mirsadm]

Maybe it doesn't apply it in the preview?

[ghost]

Unfortunately it is in the exported video too. Seems like DaVinci ignores DNG metadata.

https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=123761

[experimentator1709]

https://github.com/mirsadm/motioncam/issues/76

[amitkattal]

Is it because normal dng files from the phone has different and more detailed metadata including opcodes in it while the dngs from motioncam dont have such details so davinci cant fix the vignette?

[mirsadm]

@amitkattal those op codes are saved in there. What I will do is offer an option to apply the correction to the DNG before it's saved. That way it won't matter if DaVinci doesn't do it on its own

[experimentator1709]

@mirsadm "option to apply the correction to the DNG before it's saved"

That would be great and would suit everyone. Who wants - to fix it manually, who doesn't want - to use automatic fixing.

[mirsadm]

Could you give this one a go: https://github.com/mirsadm/motioncam/releases/tag/8.0.7-beta2

That should integrate the shading map in the DNG so it doesn't need to be done by Resolve

[experimentator1709]

@mirsadm Great job!

1. But what about optionally enabling vignette correction?
2. Do you remove the opcode with the shading map in the resulting DNG?

[mirsadm]

1. Yes that is the next step. I put this out quickly to confirm it fixes the issue.

2. Yes otherwise it might get applied twice. But once I do 1) it won't matter since you can always choose

[experimentator1709]

@mirsadm Yes I see changes in EXIF :

_ Opcode List 2 : GainMap, GainMap, GainMap, GainMap

Tile Width : 256 Tile Length : 256 Tile Offsets : (Binary data 1502 bytes, use -b option to extract) Tile Byte Counts : (Binary data 1151 bytes, use -b option to extract)

++ Strip Offsets : 1350 Rows Per Strip : 3000 Strip Byte Counts : 24000000

_ DNG Backward Version : 1.3.0.0 ++ DNG Backward Version : 1.1.0.0

_ Black Level : 64 64 64 64 White Level : 1023 ++ Black Level : 0 0 0 0 White Level : 16384

Wouldn't it be a problem that the white and black levels have changed?

[2blackbar]

My pixel has similar thing where sides are greener and middle is pinker , its very subtle but its there, so does it mean that new dngs wont have it now ?

[mirsadm]

@2blackbar have you tried the new release? that should fix it. I'll add an option to enable/disable it so you still manually do it.

[experimentator1709]

@mirsadm My shoot today is ruined. I can't correct the vignette in either the new or the old version. It worked in motioncam-tools-windows-0.0.6

https://drive.google.com/drive/folders/1O01BiX8qmLLYNJRYL3pWyK_DjjsH6g_A?usp=sharing

[mirsadm]

I'll take a look today, it shouldn't be ruined since the data is there

[experimentator1709]

and for some reason crop instead of 4000x3000

[mirsadm]

@experimentator1709 thats been fixed, thanks for sending the detailed report. Made it easy to fix. Can you double check for me that you hadn't accidently cropped the video when recording? Not sure what's going there

[experimentator1709]

@mirsadm Shot without a crop. Converted in the app. Decrease.

[mirsadm]

@experimentator1709 yep found the cause of that as well. If you still have all the containers you can convert them again when I update the tools/app soon and those issues should be fixed

[experimentator1709]

@mirsadm Thanks! I still have containers :))

[mirsadm]

@experimentator1709 could you give this one a go: https://github.com/mirsadm/motioncam/releases/tag/8.0.7-beta4

[experimentator1709]

@mirsadm Working. Thanks! My video is saved. I checked only on the converter for windows

[LuckyBastard73]

I think the correction works fine on the ZTE Axon 30 Ultra's main camera (that shows the strongest vignetting). This sample is rendered without any additional (vignetting) correction: https://youtu.be/8hqu63QVSao

[LuckyBastard73]

In photo mode the vignetting correction on the ZTE Axon 30 Ultra seems only to work on the main camera. The first image is from the main camera JPEGs created by MotionCam The second from the 35mm paortrait module Here the center of the image seems to be much warmer.