5 ms·
It can't be much worse than being under the blue sky.
by knzhou 7y ago
It can't be much worse than being under the blue sky.
- nikofeyn 7y agothis comment makes no sense. even assuming these things are equal, no one is just out there staring at the sky for hours on end for the small percentage of time the sky is actually blue.
- knzhou 7y agoSo when you're at the beach, hiking, or driving on the highway, what are you looking at instead? The blue sky is going to be most of your field of view unless you just stare at the ground.
- ta0987 7y agoThe blue sky's spectrum doesn't have a giant spike like this: https://www.benkuhn.net/img/lux/ledspec.png https://www.benkuhn.net/img/lux/ledspec.png
- knzhou 7y agoYes it does! A giant spike in the blue region is literally what makes the sky blue in the first place. If there weren't such a spike the sky would be white. When you look up at the sky on a typical clear day, you're getting more blue light than almost any one of these indoor setups.
- ta0987 7y agoI see your point, I was thinking of daylight in general. But even the blue sky is not quite as spiky: https://en.wikipedia.org/wiki/Diffuse_sky_radiation#/media/File:Spectrum_of_blue_sky.svg https://en.wikipedia.org/wiki/Diffuse_sky_radiation#/media/F... If you look at 460-470 nm where the spike is in the LED spectrum, it's much lower in the blue sky spectrum. I think the concern is something about the relative amounts of blue light. Not sure what exactly but something like, the human perception of brightness and therefore the self protection of the eye is calibrated for natural light, so the pupil contraction, looking away, etc, is not done correctly in with that unnatural distribution. Anyway I don't know if that's a real effect, but that's what people (should) mean when they're talking about "too much blue".
- rini17 7y agoBlue sky peaks between 500-550nm, this is 100nm more than LEDs, and much more diffuse.