I'll vouch for this as well. A cool test: a few hours into the later parts of a long night when your working on something, try removing flux. I was blown away by how clearly this app should be a necessity for all devs and possibly techies
I have Flux on a 1 hour shift, so I don't notice the colors changing as it happens, but it absolutely makes a huge difference. Disabling it at 10pm after a few hours of 'flux-ed' viewing feels like staring directly into the sun.
I seem to be the only one that Flux drives crazy. I know it's just my perfectionism speaking, but ... I just want to know if I'm alone in the world in my criticisms. In the past I've been stuck with old broken monitors that made certain colors look wrong or blend with similar colors, and I remember the beauty of seeing the same applications and websites render correctly on a good monitor. When I see a friend's monitors with the colors off, I feel that same feeling I get when you go to a relative's house and find them sitting around the TV with both letterboxing on and an incorrect aspect ratio (apparently it's possible) like barbarians. In the past I've had friends work on some page CSS and come up with something where parts of the text had arbitrary colored off-white backgrounds in the middle of a white page. I ask how they missed such a mistake, and then when I look at their screen you can't even notice it behind the oppressive yellow tint.
I'm sure if I ever do somehow see the light and accept Flux into my heart some day, with my luck right afterward there's bound to be some hip new product that claims that looking at an over-abundance of parallel and perpendicular lines keeps you awake longer or is otherwise minisculely unhealthy, so the product applies small distortions to the locations of everything on your screen, and people designing while they have it on will inflict similarly-jumbled messes upon their own users...
flux&al adjust colour temp, but be very kind on the backlight any time of the day. Some screens are so stupidly bright it's like staring at a bright bulb all day long. If at all possible use a screen that adjusts backlight automatically according to ambient light. And no, you really don't need that much brightness, just don't turn it all the way down either!
Do you know any good automatic-adjustment add-ons? I'd like to use the OS X option, but it seems to automatically adjust to ~2 notches above what I want. So something to use the same relative changes, but a lower absolute brightness, would be perfect. Right now I just do it by hand.
I think OS X built-in setting work just like that. I.e. turn on automatic brightness, then move slider to make screen dimmer.
I've just tried making the screen really dim, then pointed flashlight onto light sensor. The screen went super bright, but after turning flashlight off it got back to my dim setting.
Flux has been awesome for me, I've been using it for a long time. Redshift more recently, but does a good job too. Twilight for Android is a very nice counterpart for my phone.
f.lux was pretty life changing for me when I first tried it, but I'm uncomfortable with the fact that it is free-with-no-ads-yet-closed-source. That's just ... odd. Eventually, I uninstalled it and instead just started going into System Preferences by hand when it gets late in the day and switching color profiles (which is all f.lux seems to do anyway) to something that is based on a lower white point. In my admittedly unscientific testing, it seems to have the same effect as f.lux, which is what I would expect.
I hope Apple releases Night Shift for macOS soon and then I can stop manually switching color profiles around, but for now it's not a big deal.