Version Tested : 8th March 2009
Compatibility : Windows XP, Vista, Windows 7, Mac OS X, Linux

Description : F.lux is a small genius bit of software which changes the colour of your screen from natural looking to artificial looking during the right hours, in order to help you sleep better. F.lux even helps you get the exact settings for your location in the world!

When I was introduced to F.lux, I didn’t really see much of a point, and it lay dormant in my list of possibilities for quite a while. Being a university student, I have been getting a fair number of late nights working, or gaming, and I though I could at least give it a try. There’s no direct image on the site showing what F.lux does. Sure it explains how it works, the science, the logic in the idea, but no comparison images. The fact of the matter is, you have to try it yourself.

Wait I hear you mac fans cry, isn’t F.lux the same as the Macbook ambient light sensor?

Well no, but I’ll explain the exacts of this later. First, the logic of the idea. Have you ever changed the “temperature” of an image in image editing software? If so, keep that in mind. Otherwise, think about this. Computer screens are supposed to look bright, crisp, like the sun. When it gets to 11PM, 12PM, 2AM in the morning playing games or finishing that seriously long overdue essay, looking at the sun isn’t going to exactly help anyone.

What F.lux does, is give your body clock a helping hand by making the temperature of the screen warmer of sorts, with the resulting colour looking more like natural lighting rather than the bright sun glaring in your face! No more need for that bright glow in your face during the late / early hours. F.lux really makes bright screens more bearable, not by changing the brightness, but by changing the colour temperature.

Ok, to the science of this wonderful application. If you’re not scientifically inclined, this may not be very interesting, but give it a chance. I will now attempt to paraphrase one of the studies findings from the F.lux site, while explaining some of the science.

The temperature of a colour is apparently measured in Kelvins. If you’re still using a box screen (CRT), you’re probably racking up about 9300 K, average LED flat screens, 6500 K (Which is also about the same as a bright day), indoor lighting, 3000 K, candle flame, as low as 1800 K. The lower the number is, the warmer the colour temperature, while the reverse is also true. The study showed that those subjected to lower (yet hotter) colour temperatures before sleeping in an equally lit room, had better stage 4 sleep than those subjected to cooler temperature colours (like bright CRT screens). All sounds very confusing, but simply put, hotter colours with a lower Kalvin rating, means better stage 4 sleep, which means, BETTER QUALITY SLEEP!

To get F.lux to work correctly for your location, you need to enter your longitude and latitude, and it will set the correct settings. Easy right? Right! Actually, it has its own locator button, which directs you to their website where you can enter your address, town, or whatever, and it will return your long and lat, interfacing with google maps. Fantastic!

Only a few more things to mention. The default transition speed is set to fast, which changes the colour from “day” to “night” in 20 seconds. I personally prefer the gradual transition speed, of 60 minuets, which is a lot smoother! No good for colour sensitive work I hear you say, well no, but you can disable F.lux for 1 hour at the click of a button.

Oh, 2 last things. About the whole F.lux is like the Macbook ambient light sensor, well sort of, but not quite. The Macbook sensor changes the brightness of your screen (Which is something I wouldn’t mind having), while F.lux changes the colour based on the time. It’s reported that they actually work very well together. The final last thing I was referring to was the man behind the app, also was the genius behind Google Picasa!

He is @herf on twitter, I am @relequestual on twitter. I have actually started using twitter more, if anyone is interested.

Conclusion : F.lux is one of those apps that once you start using it, you won’t be able to do without it. Turning it off will put a reaction on your face similar to that of a vampire to light, no jokes. People who use computers during hours when it is dark outside, WILL benefit from using F.lux. Better sleep, better work, better fun!

Website : www.stereopsis.com/flux
Download : Page as above – Direct Windows, Mac, Lin
Size : 545 KB, 1.19 MB, 323 KB