I’ve noticed that my reality illusion doesn’t usually appear until I add dark and light areas. One of the last things I do with a painting is add black to the darkest areas and white to the lightest areas. The human eye sees a larger dynamic range than most film or digital images. Digital images can sometimes see into the infrared and specialised film and cameras can see far into the Infrared and Ultraviolet range. Film registers about 5 stops of light in the visual spectrum, and photographic prints show about 3. The print range has more to do with paper and ink, a projected image is capable of much greater range.
When I say a stop that is a photographic ‘stop’. A ‘stop’ on a camera is generally a factor of 2, so 5 stops is about 64 times the amount of light between the darkest and lightest areas. However, your eye is also capable of changing its aperture, so depending on who you talk to and how they are parsing the data you can get into the millions. The Lumen is an exact measurement of light but not a measure of colour. I don’t know what the relationship is between a lumen and millions of colours. A photo print with a full 3 stops of dynamic range looks pretty good. I believe a painting with today’s pigments is better than a photo print but likely not as good as your computer monitor. Your monitor might actually be able to show millions of colours; a photographic print can not, but it can fool your brain. Your eye can see and your brain can process millions of colours but not equally in all parts of the spectrum; you are much better at detecting shades of green than red for example.
As an artist the way light is measured or how the units are named is immaterial. What matters is how it looks. I’m interested in how light is measured and how a photographic image is rendered but it has nothing to do with me as an artist. It’s likely possible to mix millions of colours with today’s paints but all I need to do is generally match the art with what I am seeing or what I mentally think I should see, and it starts to look real. As long as I can match what I’m painting to what I’m seeing, then knowing exactly how this happens is immaterial. Interesting but immaterial.