r/DarkTable • u/ScountMcQuaint • 6d ago

Help Red shift help

My histogram shows in most if not all my RAW photos the red channel is exposed higher than other colors. Even after adjusting white balance and other visual adjustments to get what I want, the red channel is shifter farther right than others. What might be causing this, and what's the proper way to correct it? For context, these photos are outdoor daytime travel pictures, or indoor photos of my kids.

Here's one example. There's lots of red brick, but it doesn't appear to be brighter than the blue and white in the sky.

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u/ofnuts 5d ago

it doesn't appear to be brighter than the blue and white in the sky.

The "white" in the sky is a bit pinkish to me...

1

u/MortimerMcMire315 2d ago

Yeah, /u/ScountMcQuaint your highlights were likely clipped in that photo and they have a magenta hue. Check out this tutorial for help with that.

Or your color calibration is just off. Try calibrating it using the eyedropper on the "white" sky.

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u/MortimerMcMire315 6d ago

Do the pictures themselves look too red as well? First of all, if not, I'd say don't get too bent out of shape about how the histogram looks, it can really be deceiving compared to how your eyes see an image.

If they do look consistently too red out of the box, one easy solution is to duplicate the color calibration module, make sure the adaptation in the CAT tab is set to none (bypass) (should happen by default on CC duplication), navigate to the R tab, and reduce Input R by a small amount.

You could then save that as a style and apply it to all images from the red-prone setup.

There are a number of reasons this could be happening -- I have a Minolta lens, for example, that causes my images to come into Darktable with too much green. I decrease the input green whenever I use that lens.

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u/akgt94 6d ago

A picture would help a lot. Maybe there's something bright red or orange or yellow in the photo. Doesn't seem incorrect.

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u/ScountMcQuaint 6d ago

I shoudl it might be warm lighting, but if I make that adjustment the picture is grossly cool before the red comes into alignment with the other channels. But, I see it on outdoor daytime photos, too.

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u/davep1970 5d ago

Then post some examples.

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u/ScountMcQuaint 5d ago

OK, it's not the best choice since it has a lot of red, but the others had family in them.

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u/davep1970 5d ago

Post pictures and their histograms. Use a brush or similar to hide identities. No one can help you unless you post pictures and their histograms. (Imgur, Dropbox link or whatever).

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u/MortimerMcMire315 5d ago

honestly it sounds like you're just obsessing over the histogram for no reason. It's just an objective view of the distribution of light in your photo. It doesn't really matter at all. What matters is what you see with your eyes.

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u/Past_Echidna_9097 4d ago

I set my camera to use daylight which is around 5400 Kelvin and never change it. Works well.

1

u/Donatzsky 2d ago

That doesn't influence the raw data.