I picked up a low pressure sodium lamp and am working on a Halloween demonstration. I’m hoping to make a display that appears one way under normal light, but looks totally different under the monochromatic 589nm sodium vapor light.
So basically, I’m looking to generate a color wheel where I pick a shade of gray and get a list of colors that would look that gray under sodium vapor light.
…I feel like there must be a Python library for thing or something…
Hmmmmmmmmm… From a high level perspective you need to know the reflectivity of your combined pigments at that wavelength. If it’s the same, they will look the same.
I don’t know of anything easy you can use, but would suggest trying to find reflectance curves for each pigment you have available and making combinations that subtract to the same value at 589nm, or since 589 should be basically yellow, make up some colors where Y is constant and you change the ratio of C to R and try them out?
That’s true! Using RGB alone will not be enough to calculate this! Two materials that might appear equally yellow under white sunlight may appear different shades of yellow under sodium light. Technology Connections did a great video about the difference: https://piped.video/watch?v=uYbdx4I7STg
edit: he starts talking about sodium light in particular at 11:14