If your display is calibrated for a D65 whitepoint, would simply dialing in a 6500K WB mean that end-to-end WB is more or less constant?
Quite possibly so. Playing around with Bruce's calculator mentioned below does indicate that if an image comes into the camera with a color of XYZ then the RAW file gets RGB values according to our, or the camera's, best guess at the illuminant. Which I'm beginning to think makes the question in the OP impossible to answer, there being no illuminant . . .
I am guessing that self-glow objects can look more realistic on a (self-illuminating) screen that on reflecting paper?
. . . impossible to answer because, instead of the WB being set for the scene illuminance it is instead set for the output. That it is to say, a colorimeter test would show that my uncalibrated monitor would show a different color to your perfectly calibrated monitor and different again to theguywitha645d's printer output (under whatever lighting he uses)
WB is not fixed until you process, so whatever you set the camera to is just a placeholder and does not effect the image.
Er - thank you.
If the channel you are imaging has its center wavelength in clearly in the green channel, you really have nothing to worry about.
Although it asked a specific question, the OP was trying to be general and theoretical, not about green as such. Green self-luminous images are all that I had to hand. How about a car amber side light next to a red rear light and a blue cop light, all in the same image?
Either set the WB to daylight (5500K) or whatever color temperature of the light source used illuminating the sample. However, if there is a bleed to the R or B channels, then you have a color problem. But a color in a file does not represent a wavelength at that point. What you do is make the white light image look natural and then use selective color to give the green you want.
In the OP, I should have said that the objects are not illuminated by another source which is what I meant by 'self-luminous', so there is no light source illuminating the example. Good point about wavelength, though. Bruce Lindbloom uses the term 'dominant wavelength' in his CIE color calculator, accessible from here
. Always fun to play with, many choices of illuminant and white point correction matrices, color spaces, etc. Interestingly, if you set an XYZ there and then change the illuminants, the RGB values change but the CCT and dominant wavelength do not. Makes sense - further confirming that WB is only to do with reflected light and that camera makers do not expect accurate color rendition of Christmas tree lights shot in the dark?
Could I ask what was meant by 'a bleed to the R or B channels' although I'm not asking for trouble-shooting of my images.
It is possible that your green is out of gamut or it is clipped.
Again I was trying to talk theoretically, not really looking for image comments per se
. But I agree that out-of-gamut problems can show up. I had one image that puzzled me for weeks - a yellow flower was in-gamut in the camera RAW file but out-of-gamut in Adobe's ACR screen rendition of the working file. Reducing saturation just messed up the image coloration. Other converters e.g. dcraw handled it more gracefully after messing with the clipping options.
I propose that the question does not have a unique answer, in that WB setting varies with the desired output.
All those in favor, say 'aye'.