The Story Behind F.lux

Android announced "Night Light" and Kindle added "Blue Shade" and iOS came in last with "Night Shift" so it appears everyone has.

When F.lux put up affiliate links hawking Himalayan salt lamps and Swarovski crystals and used "cancer" as the 30th word in a press release, I didn't feel too bad hitting "uninstall" for the final time. So Long, and Thanks for All the Tint.

[0]: https://justgetflux.com/news/pages/macquickstart/

I know you can invert colors in OSX but the effect is desktop-wide and you can't use a hotkey to enable or disable it. Does something similar exist for other OSes?

"...Now to be fair most of this is the result of OpenBSD ports choosing to build and package optional dependencies, including the GUI..."

I suspect the people who produce and maintain the ports builds are putting all the options in to cover as many use-cases as possible. I've noticed that some OpenBSD ports give alternatives to pick from with different compilation options. I suspect that might be impractical for many choices.

Now I'm wondering if I can build sct.c on the Slackware box and have a play with a bash script setting the colour temp by time of day for current latitude...

personal) I'm colorblind and it really messed with my ability to guess at the appropriate colors, and sometimes made it impossible to read text on the screen. (Red on black is hard for me)

science) One of their more prominent articles showcases a study of how reading on a stock iPad can mess up your sleep a lot, but reading a book with standard bulb (much warmer than the iPad backlight) has a much smaller effect. I remember studying the effect of light in neuroscience classes in college, and blue light is potent, but so is total light received. Indirect light from bulb, or having a device blast light directly into your retina. Never stood a chance. Just shifting the colors can only reduce so much light. For example, max out the brightness on any non oled based screen with a completely black image. You still see light even though those gates have done the best they can. My general impression of the reporting is "lets throw a bunch of science at you, which doesn't quite say what we do, and hope you jump to our conclusions."

* You can adjust the color temp it goes down to. I'd try a more moderate setting, at least at first.

* You can have it transition gradually.

* If the room you're in is lit with daylight bulbs, you won't really benefit from it and it will look weird.

* It's no good for doing color-sensitive work, so no photo editing, etc.

I really can't imagine using a computer in the evening without it.

I tentatively tried using melatonin tablets instead, and I've found it works really well for me. Set an alarm for about 30-40 minutes before you want to go to sleep, take the tablet (sublingually) when the alarm goes off, and you'll notice you start feeling sleepy right about when you need to fall asleep.

Obviously, this kind of exogenous melatonin intake can only crudely approximate the curves for plasma melatonin levels resulting from endogenous production in the presence of zero artificial light, but using f.lux only removes one source of blue light. Sure, you might feel sleepy staring at your screen, but blue light inhibits melatonin synthesis so strongly you could turn on your bedroom light and have your melatonin production bottom out. IIRC, you can significantly attenuate melatonin production with light levels of ~100 lx, which is comparable to a really dim room. Good luck getting ready for bed in complete darkness.

You also need to titrate your dosage to find the right levels. For me, 0.2-0.5mg is all I need to achieve the necessary sleepiness to motivate me to get to sleep. I can take more with no noticeable effects, but I know others who report headaches the morning after. Also note that the older you are, the less melatonin you need.

Not sure about the angst. Maybe the people behind it are annoyed, or its just good fodder with the Apple connection.

This is where computer displays confound things, because they are a source of light, but they are used among other sources of light. And those light sources change over the course of a typical day. And thus the white balance changes over a typical day. Let's say you're using a computer in an office with white walls. Those walls don't seem to change color throughout the day, but they very much do, because the light illuminating them changes. From sunlight to artificial light. Your eyes adjust to this naturally though. But computer displays don't change, which means that during daylight hours your eyes might perceive the display as being normal while after sunset your eyes start to see the display as blue-ish or excessively bright. Alternately, your eyes could perceive your surroundings as different, seeing artificial lighting as yellowish and dim.

F.lux is simply an attempt to harmonize the white balance of your display with the white balance of your surroundings, based on some information about the type of lighting you have and the local times of sunrise/sunset. Once you get used to it it seems perfectly normal that displays should do this.

The problem is that a lot of the underlying technology (monitors, display drivers, OSes, etc.) are built on entirely different assumptions, the idea that the display itself is a universal arbiter of the "correct" color choices and there's no need to white balance harmonize with the rest of the world. Which means that sometimes it's difficult to get something as simple as F.lux to work on a given platform.

That's why it's a topic of frequent conversation. It should really be a feature built into all displays and operating systems as it's a very straightforward idea. And essentially every digital imager in the world is built based on a universal understanding of the need to account for white balance, but there is still an uphill battle in getting people to understand the need for white balance management in digital displays.