The main purpose of this graph is to compare "melanopic" light, which is light in the blue-green area between about 400 and 580 nm (the gray curve). This is the

The main purpose of this graph is to compare "melanopic" light, which is light in the blue-green area between about 400 and 580 nm (the gray curve). This is the sleep-disturbing blue light everyone is talking about, which also includes green, as you remarked. The vertical scale is just relative power from 0-1, for the relative amount of light at each wavelength, as you said. Why not normalize? Because those other sources are twice as bright. We're trying to compare to a light source people would typically buy. Yes, you could use a ~40 watt incandescent at about the same lumen output, but it would still have a higher melanopic effect. The melanopic ratio for incandescent is usually around 0.50-0.54, which ours is 0.39. You'll also notice that we did not include a daylight LED in our comparison, which is something our competitors do, but we think it's just a ridiculous exaggeration of the effect. In other words, if you pointed a spectrophotometer at the 4 light sources at a consistent distance and did not normalize, that is roughly the plot you would get. If we take reading as a use case, there are aspects of our design which enable you to use a source that is half as bright and still read just as well. For one, the CRI and R9 (red color rendering) are very high, basically at incandescent levels. This makes the printed page look better. The beam angle is much wider than a normal LED (most LED bulbs mounted upright will shoot all the light at the ceiling, not where it's needed). And most people simply don't need a 60 Watt bulb (650-800 lumens) to read with, even if they don't yet realize it. Why not eliminate all blue and green? It's certainly possible, and there are bulbs that do that. The problem is that blue/green-free light is very orange/yellow, and in our testing, most people found the light undesirable and impractical. Our theory is that people would go back to their old higher-blue lighting after some time. In other words, people like white light. However, we are working on a mostly melanopic-depleted source with a slightly different use case. The point is that it comes down to both spectrum and illuminance (brightness). Everyone else in the market is only considering spectrum. There is an explicit tradeoff between color rendering (CRI, R9, Rf, Rg) and the amount of blue/green reduced. If you can balance those two, and then give someone between 100-200 lux, as opposed to 300+ lux for typical reading light, the melanopic input is much lower and the light is more comfortable to use for most people. Our light will give you about 100-200 lux in a shaded or unshaded lamp at a typical reading distance. But it's hard to explain that from a marketing perspective.