I'm shooting a scene for a film where the actor will be placed in front of a computer monitor. I want to use the monitor to light the actor, but I want to be able to adjust the color temperature to get the look I want. I have F.lux (https://justgetflux.com/), so I know changing monitor color temperature is possible, but I want to be able to control it. Preferably the program would be free, and I would be able to adjust the temperature in real time.
If you can't adjust the monitor, then send it something other than pure white.
@poor already posted an answer to do this with Blender, but that seems like HUGE overkill. I would have just booted Linux, logged in remotely, and done
DISPLAY=:0 xsetroot -solid '#fff' to set a solid white background, or any other color I wanted.
And there's probably something you could run to open a fullscreen window with a color of your choice, to save the trouble of switching to a window manager that didn't clutter up the screen borders with stuff. Maybe a screensaver type of program?
I can't think off the top of my head what would give you a GUI color adjuster that would change most of the screen in realtime.
Here is a hack. You can use Blender and the Blackbody Node of Cycles Render Engine. Following example shows a realtime viewport animation of the color temperature in kelvin:
- Create some geometry (e.g. a plane) as light emitter
- Setup an Emission shader
- Create a Blackbody node and plug it into the Emission Color
- Position your camera
- Switch your Camera by pressing Numpad 0
- Set the Viewport Shading to Rendered or press F12 to render the image
Thanks for the other good answers. Here is what I ended up doing.
I created a blank white html page and made it fullscreen, and then used f.lux to adjust the color temperature. It worked for me, but I should point out to anyone looking to use this solution in the future that it isn't perfect. F.lux doesn't give a very broad range of color temperatures. They were enough for my purposes, but someone looking for a very warm or very cool look might not be satisfied. In addition, f.lux changes the color temperature for the entire desktop on all monitors, so if you have something color-sensitive running during the shoot, like using the computer as a monitor, your colors will be off on that as well.