Given hue and saturation of a color, how to generate colors in evenly spaced relative luminance level?

Question

Given hue and saturation of a color (H & S of HSL), how to generate colors in evenly spaced relative luminance level? E.g.

Source: http://www.workwithcolor.com/hsl-color-schemer-01.htm

If I give it a pure Red @ 50 relative luminance, how can I mathematically generate RED at different relative luminance in 5 - 10 stops?

Answer 1

A lot of interesting things may be found in sources of LESS, which has some built-in color-calculating functions, listed here (search for 'rgb', that will be the first one).

Going to implementation, take a look for their one-liner for luma function, which should return luminance of a color.

Answer 2

What I ended up doing is a dumb linear search from 0 to 100 in L of HSL and stop when it reaches one of the Lum stops.