[lectrick]

It doesn't "remove brightness magically", it just swings the color temperature of ALL colors displayed towards the red end of the spectrum, which studies have shown can decrease the inhibition of melatonin production which means you will be more likely to get sleepy around the time you're supposed to, whereas before you might not have until much later and disturbed your sleep.

http://en.wikipedia.org/wiki/Color_temperature

[diminoten]

What aren't you getting about this? There is leakage of white unfiltered light that comes from from most monitors (the super duper high quality monitors boast about low light leakage, but they still do it a bit). F.lux cannot possibly change the color temperature of this light. So my question is and has been, does that leakage have enough of an impact to negate the effects of F.lux? That's the question worth answering, because if it's, "No, the effects are negated by the white light leakage", then there's absolutely no point in using F.lux whatsoever.

[lectrick]

That light is negligible. I have used F.lux for years, I swear by it, and if I bring an iPad or iPhone to bed and stare at it a while before I sleep (note: don't do this), I can totally notice the difference. (Then again I have a diagnosed sleep disorder and have to be extra careful about these things.)