Grain added to my RAW low-light high-ISO photo, gone when moving around

[ariaameri]

Hi!

This is the first time I am taking RAW images with my Nikon D7200 and I am facing a problem. I searched a lot for it but I could not find it.

I have a low-light, rather high-ISO (5000) image and Lightroom (version 8.3.1) on my mac adds grain to it. I tried turning off 'Use Graphics Processor' in the 'Performance' tab of the app preferences and turned off all the panels including the 'Detail' panel so that they do not affect my image. Now, in develop mode, when I drag (pan) the image, all the grain in the image is gone (and it looks better!)---first image attached here---but as soon as I stop moving the image around, the grain comes back to the image---second image attached here. I tried using different profiles (even with different 'Amount's) but the issue remains.

Moreover, when I export the image as JPEG with sRGB color profile at maximum quality, all the grains are present! Perhaps it's good to mention that this grain is not present in the JPEG file rendered by the camera itself.

If it helps, I checked and the color profile of the RAW image (with NEF extension) is 'Display P3' and my monitor color profile is set to sRGB, but changing my monitor color profile won't make any difference.

Could you please tell me why this is happening? and how can I turn it off (but in the preview it shows me inside the Lightroom and for when it exports to JPEG) so that Lightroom does not add grain to the image, as I do not want it?

Thanks a lot!

- screenshot for while dragging the image, no grain:

- screenshot for not dragging the image, added grain:

[Per Berntsen]

ariaameri wrote

Perhaps it's good to mention that this grain is not present in the JPEG file rendered by the camera itself.

Jpg files are processed in the camera, and this processing includes noise reduction and sharpening.

When you shoot raw, you have to do this processing yourself.

First of all, when judging noise and sharpness in an image, as well as when applying noise reduction and sharpening, you have to work at 1:1 view. This is the only view that gives you a true impression of the image, because one image pixel is represented by one screen pixel. Any other view will be inaccurate and misleading, because the image has been scaled.

The image is very noisy, and contains both color noise (colored blotches) and luminance noise (grain).

Shooting at ISO 5000, and underexposing by three stops will produce lots of noise.

(Underexposing three stops at ISO 5000 is like shooting at ISO 40000)

At 1:1 view, first reduce color noise with the Color slider in the Detail panel.

Then reduce luminance noise with the Luminance slider.

Finally, apply sharpening, and pay particular attention to the Masking slider. Hold down the Alt key (Option on a Mac) while dragging the slider. The image turns temporarily to black & white, and white areas will be sharpened, black areas will not be sharpened.

At 0, everything will be sharpened, at 100, only the most distinct edges will be sharpened.

Noisy images like this require a high masking setting, because you don't want to sharpen the noise in flat areas of the image.

[ariaameri]

Hi,

Thank you so much for your help!

The view is right now 1:1. I tried the color and luminance noise reductions and applied sharpening and masking. That was very helpful, thanks!

I understand that there is color and luminance noise present in the image, especially when underexposing. However, when all configuration panels are off (even when I do not fix the exposure, and the image is not under/over-exposed) and the 'Use Graphics Processor' tick is off in the preferences, when I drag/move the image around, the image is fine with color/luminance noise present in the image, but as soon as I release the mouse button (so I stop moving around the image) a lot of grain or luminance noise is added to the image inside Lightroom, whatever the color profile is. My question is what is that added monochrome grain, why it is being added, and how can I turn it off? Because sometimes it really deteriorates the quality of the image as it adds extra monochrome grain and when exported as JPEG, the monochrome grains are still there, which not what I want!

Thanks beforehand!

[JP Hess]

The image IS underexposed. Look at the histogram and you can see that. The reason there isn't any "noise" when you move the image around is because Lightroom isn't able to focus on the image to present an accurate preview.

[Per Berntsen]

Ignore what the image looks like when dragging it – it's irrelevant.

To see a correct rendering of the image, just view it at 1:1, without dragging. What you see at 1:1 is what you've got, and it should display the same with the GPU on or off.

[ariaameri]

Thank you very much for your explanations Per Berntsen and JimHess!