Increasing vibrance in HDR mode destroys colors in bright areas

[John15]

Use the attached photo and develop into HDR (ROMM RGB 32-bit).

Try increasing vibrance 1% in develop mode, or as an adjustment layer.

The attached screenshots doesn't really do it justice because I'm unable to screenshot in HDR. But you can clearly see a blue squarish region disappear when I increase vibrance to 1%. Such issues doesn't occur when decreasing vibrance, or adjusting saturation.

AP version: 2.5.7 on Windows 11

DSC_0238.NEF

[Ldina]

On Mac, the small blue square doesn't vanish when increasing Vibrance, but the center of that blue square does change significantly (not in a good way), in 32 bit linear, in both Develop and Photo Persona. That doesn't happen with Saturation, just Vibrance. I also tried Apple Core RAW engine (only on Mac) and that didn't do any better. Saturation may be a possible workaround. That happens whether my monitor is set to HDR (XDR on my Mac) or whether I choose to set my display to SDR.

Converting the file from 32 bit linear to 16 bit P3 profile in Photo, changes the appearance of that blue square, even without any image adjustments. This suggests to me that perhaps some of the colors in that square may be at the very edge of the color gamut. I'm not entirely sure. Once in 16 bit, Vibrance seems to work normally. If you need 32 bit linear output, I guess saturation might be the way to go. If you don't need 32 bit linear, 16 or 8 bit SDR would be a possible choice. 

 

[David in Яuislip]

It's a modern phenomenon, V1 does this

[John15]

  

22 minutes ago, Ldina said:

Converting the file from 32 bit linear to 16 bit P3 profile in Photo, changes the appearance of that blue square, even without any image adjustments. This suggests to me that perhaps some of the colors in that square may be at the very edge of the color gamut.

That's because when you use 16-bit, all the HDR information is clipped to SDR range. It's not about the color gamut, it's the intensity (luminance) that's causing clipping. AP doesn't have a 16-bit HDR mode. HDR mode is 32-bit only.

22 minutes ago, Ldina said:

If you don't need 32 bit linear, 16 or 8 bit SDR would be a possible choice.

I do need 32-bit linear because I want to export an HDR image.

8 minutes ago, David in Яuislip said:

It's a modern phenomenon, V1 does this

Since the colors in your screenshot is properly visible even in the brighter parts of the image, I have a feeling that you have not increased the exposure enough to bring those pixels to the HDR range. After opening the NEF file (with develop assistant settings "RAW output format" set to "RGB (32-bit HDR)", I set exposure to +3.0 during develop.

[David in Яuislip]

Ok, +3stops

[John15]

2 hours ago, David in Яuislip said:

Ok, +3stops

It definitely looks different to mine, when comparing our screenshots. (EDIT: Simplify question since it looks like you're in HDR mode from the screenshot, and assuming you're using an HDR screen.)

Can you confirm that you're not seeing any sudden changes when changing vibrance from 0 to 1%?

Edited December 15, 2024 by John15
simplify

[Callum]

Hi John15,

Apologies for the delayed response is this something you are still having issues with?

Thanks
C