Changing a selected color towards a specific RGB value
I have to photograph various sorts of colored fine art paper. Tricky, since there are some surfaces with metallic particles. Although I do regular white balance shots, the RGB values I read out Capture One 9 (Mac OS) are of course not really the same as the should-be-values provided by the paper maker. I had really no use for the color editor in C1 so far, so I`m not familiar with that tool. The question is: Is there a good and fast way to tweak a once selected color towards the very specific should-be RGB values? Thank you kindly!
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I think you might have success with the skin tone tab in the white balance tool. (It doesn't just work for skin tones: really it is a way of setting white balance by getting a particular colour right rather than by getting a particular tone to be neutral grey. And it's a completely different thing from the skin tone tab in the colour editor tool, which is for evening out skin tones, or other colours.)
You will need to start with an image that does represent the colour you want correctly. Then you go to the skin tone tab in the white balance tool, and check the box for click to create new. Then use the colour picker to click on the colour you want in your image, and save the result under the name of your choice. ("Apple Green" or whatever.) Then whenever you have to get that colour right in another image you go to the same tool, select your colour "Apple Green" from the drop down list and click on the object in the image that is meant to be that colour. This will adjust the white balance to achieve that outcome.
Ian0 -
Thank you kindly for that idea. I will try it right away, but the first problem will be to get that start-image, that base color right. I ran into that problem, because I did a test shot with that paper. and I was given the RGB values of that specific color by the paper maker. I have 3 different white balance tools in my studio (a CaliCube, a Sekonic Grey Target, a XRite ColorCheckerPassport) , but no matter which tool I use, the color of the paper is not even close to the should-be RGB values. The light sources are professional Elinchrom RX monoblocks, I don`t think that they give a different color temperature which each flash, in fact they are very stable.
I have 10 different types of paper, and each type comes in 15 colors, and each type and color comes in 7 different formats (flat paper, envelopes, greeting cards and so on). It`s really strange how off the RGB values are in the test images, and I need to push them as close as possible towards the desired should-be values.
Your idea is fine, but depends on a correct start-image I can base the rest of the images on, and I have trouble getting that one correct base image per color.0 -
If you are trying to match the RGB values on C1, I also wonder whether you could change the Curve on Base Characteristics to Linear Response. Maybe that would eliminate as far as possible any adjustments that C1 is applying before you even see the image. (It's on the Colour tab.)
Ian0 -
Oh yes, good idea, I didn`t think of that. Will try it right away. 0 -
Or could you create a file using say Photoshop, Affinity Photo, etc that allows you to create a specified RGB colour, import that into C1 and use it to pick your "skin tone" from? So you could just create some text or something and set its colour using RGB values.
Ian0 -
THIS is definitely an idea I wasn`t even close to thinking of.... Thank you kindly, this may be a good way to go! 0
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