f.lux™ Better lighting...for your computer

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Click here to find out how to install or uninstall f.lux

Configuring f.lux

1. How do I find or change settings?
   Settings are located in a menu to the left of your system clock. In Windows, this is at the bottom right corner of your screen. On a Mac, it's at the upper right. NOTE: f.lux does not appear in your docking bar, settings, or your alt-tab menu. Currently settings are only acessible through the taskbar.
2. I installed this but it looks too pink/orange.
   On first use, it can take a while to adjust to the halogen settings. Try adjusting the color temperature sliders under Settings until you find one you like. Start with fluorescent or halogen and change it when your eyes adjust. When you disable f.lux, your screen will return to your normal calibration. We're used to looking at very blue computer screens, so it can seem unnatural at first. Most LCD displays are calibrated to display at 6500K, which has even more blue than noon sunlight (5500K).
3. My cursor is blue on Windows. Why?
   This happens when your videocard displays your cursor in hardware. We're looking into a workaround.
4. What is the right color setting for me?
   You're at the right color when your monitor screen color looks like the pages of a book under your room lights. We're all used to monitors giving off a 6500K glow, which is even bluer than sunlight. If the default settings of f.lux feel too extreme to you, try setting it to fluorescent, and once your eyes adjust, set it to a warmer temperature. Some studies indicate blue light is beneficial during the day, but late at night it can negatively affect your sleep pattern. Our unofficial study indicates that f.lux makes your computer look nicer in a dark room.
5. This changes too fast, it always shocks me.
   The f.lux transition can be CPU intensive, so f.lux tries to be polite about it. To make it slow, you can use the special 1-hour slow transition option under settings instead.
6. I work nights. How do I flip the day and night settings?
   PC f.lux users can unlock the color temperature sliders by holding down the control key while setting your temperature, so night can be swapped with day. We're working on a feature that lets you control time settings more closely.
7. What are the Mac presets in Kelvin?
   Tungsten: 2700K
   Halogen: 3400K
   Fluorescent: 4200K
   Daylight: 5000K
   Disable for an hour: 6500K
   

Troubleshooting

1. I installed f.lux but I can't see any change.
   Is it past your local sunset time? Just wait, and f.lux will kick in at sunset.
   Is your location set correctly under Settings?
   Check that your night-time settings are not set to Daylight.
   
2. F.lux makes my mouse stutter, makes my computer slow, and doesn't seem to change my colors at all.
   Most problems like this can be fixed by updating your video drivers.
   Try one of these links: NVIDIA drivers, ATI drivers, Intel drivers.
3. I use Shades on my Mac, and f.lux is fighting with it.
   We recommend you only use one of these programs at a time.
4. I have a DisplayLink USB monitor adapter. Is there a way to make f.lux work for this display?
   DisplayLink has no support for color calibration, so f.lux can't make changes to DisplayLink monitors. Unfortunately, you can only use f.lux today on displays that are directly connected to your computer. (e.g., it usually won't work over remote desktop either.)
5. Something else is going wrong with f.lux for Windows
   We always recommend updating video drivers as a first line of defense. If you're experiencing flickering or problems, please upgrade your drivers. If that doesn't work, we love to fix bugs. Please post a note in the comments section with information on your operating system, video card, and any other information that might be helpful to us.

More questions

1. Plenty of things already change the brightness of my screen. Why is this different?
   f.lux changes the color temperature of your display. Natural light is more blue, while most artificial light (including candlelight) is warmer. Incandescent bulbs, which we're all used to, become more red in tone when you dim them. But newer LEDs and CFLs don't - this includes the backlight on your monitor. If you're a photographer, you've probably dealt with this, since pictures taken inside at night are always much more brown than photos outside.
2. Isn't this exactly the same as the Macbook ambient light sensor?
   No, though they do work together nicely. The ambient light sensor measures the brightness of the light in your room and adjusts the brightness of your screen based on that. f.lux changes the color of your screen and warms it up according to the type of light you're using and the time of day. f.lux doesn't use ambient brightness to adjust colors. You might be in a dark room with very cool light, you wouldn't really want your monitor to look warm, but you would want your display to look dimmer. We've found that when your screen colors match the color of your ambient light correctly, you don't need to adjust monitor brightness as much.
3. What is color temperature, exactly?
   The term color temperature is a way to numerically describe how much red or blue light is illuminating a room. Color temperature is measured in Kelvins, and is determined by the kind of light you're using. Confusingly, warmer (more red) light sources are described in lower degrees Kelvin. Compared to indoor lighting, daylight is cool - very blue. A candle is around 1800K, while a sunny day might be 6000K. An overcast day will seem more blue, so it might be around 7000K.
   Most computer monitors display around 6500K. If you are using incandescent task lights behind your computer, those are around 3000K.
4. I'm a designer / photographer / artist so I can't use f.lux. This isn't for me!
   f.lux was created by people who care a lot about accuracy in colors. We know you want to make sure your colors are perfect so there is an option to disable f.lux for 1 hour at a time (for example, while using Photoshop). This setting returns your screen to its normal settings. In the future we plan to allow automatic disabling of f.lux when you launch certain programs. f.lux is not designed for use during advanced color work, but it's fine for layout or HTML. Currently, we don't recommend running f.lux on calibrated systems running Windows, but we expect to have a solution for this soon.

Installing & Uninstalling

Windows Install

1. Click the f.lux Windows download link.
2. Run the installer and the f.lux settings page will appear.
3. Enter your location and select the type of lighting in your room at night.

Windows Uninstall

1. Go to the f.lux Settings panel (to the left of your system clock)
2. Choose "Quit f.lux"
3. Go to the Start Menu > Add/Remove Programs > Uninstall f.lux

   IMPORTANT: if you uninstall before quitting f.lux, in some cases, f.lux's color remains after uninstalling. The fastest workaround is to reinstall, then quit f.lux (your screen should appear normal). Uninstall according to the instructions above. This is a high priority bug that will be addressed in a future release.

Mac Install

1. Click the f.lux Mac download link.
2. Choose "Open with Stuffit Expander" and click OK.
3. Copy the "Flux" app to your Applications folder.
4. Double click the "Flux" application in your Finder window.
5. Enter your location, and select the type of lighting in your room at night.
6. Select Start f.lux at login and click Done

Mac Uninstall

1. Go to the f.lux Settings panel (to the left of your system clock)
2. Choose "Quit f.lux"
3. In Finder, select and delete the f.lux app.

Linux

Ubuntu-inside.me has written a great guide to using f.lux:
www.ubuntu-inside.me/2009/03/flux-better-lighting-for-your-computer.html

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