Koraks or Helge OK here's what Helge said : "LED lighting is terrible. Very lumpy, uneven spectrum. Terrible for humans eye regulated hormonal system "
He used the word "terrible" and that sounds as if it might be serious for our hormonal system
So what limitations do we sensible place on LED lighting involved with photography such as: Not have any in our darkrooms, houses
Have limits on use and if so what limits It might have been a largely humorous comment and not meant to give us real concern for our hormonal system and that's fine but it is not clear to me that this is the case based on that one sentence
pentaxuser
It’s a giant and very complex subject. And you’ll find many scientists disagreeing on what we actually know for certain.
Hormones that regulate the whole body and its circadian rhythm, energy level, hunger and sexuality etc. is to a very large degree influenced by light.
The amount of it and very much the colour of it, and the precise composition of the spectrum.
For example, we have coevolved with fire, so it’s natural that when we sense that particular spectrum, we feel calm, cozy and eventually sleepy.
I wouldn’t use LEDs as safety lights in a darkroom.
But their use in enlargers is a new an exciting use for which their org. physical colour might be perfectly suited.
For lighting a digital set they might be adequate (still I’d prefer one of the black body radiator
alternatives. Or flash for photography).
But for lighting a film based shoot, they can very easily introduce a colour cast, subtle and not so subtle, that is impossible to remove well, because of the nice peaky nature of the colour sensitizing dyes used in film emulsions.
It’s less of a problem with B&W, but still might cumulatively offset metering, and could subtly disturb contrast.