[tzs]

> My computer might not be half as fast, but at least I know my blues are the shade of blue I think they are.

I've wondered if one could do color calibration using any ordinary digital camera and some clever software, but don't know enough about how color calibration actually works on computer to figure out if it would actually work.

The idea is that you would have some reference photos of assorted physical objects of known colors. The physical objects are chosen to be items that are commonly found around the house or office, or are cheaply and easily obtained.

You pick such a physical object, place it next to your monitor, and tell the software which object you are using.

The software then displays several images of that item on the monitor. One is the reference photo, and the others are tweaked versions of that reference photo that tweak the colors.

You then take a photo with your camera, showing the images on the monitor and the object itself. You upload that to the software.

The software then compares the object in the photo to the images on the monitor, and figures out which best matches. From this, it should be able to deduce some information about how accurately the monitor is displaying color, and what adjustments could be made to improve it.

Note that this does not depend on the camera being accurately calibrated. It just depends on the camera being consistent, and having enough color resolution to see the tweaks that the software applies to the images on the monitor.

Note also that this should work for more than just calibrating monitors. It should also be able to figure out a color profile for your camera along the way. Then it should be able to print some test images, have you take photos of them, and from those and the camera color profile figure out a color profile for your printer.

[mxfh]

Color calibration is a chain, you need to know if your camera is calibrated too, so you need at least standardized targets, finding random objects of known color that cover the whole color space sufficiently is not trival, only then you could use your calibrated camera to measure a displayed target.

But I wouldn't cut corners there and just get a calibration device for about $100 plus a standard color calibration target. Certainly more sensible investment, then the difference between a 2k and 6k rig.

[07d046]

Interesting idea, but I think there's a variable you're missing, which is the light by which the physical object is illuminated by. The colour temperature and spectral power distribution of the light makes a difference. If you used a custom white balance in your camera you should be able to get the colour temperature close to right (depending on how neutral the camera is), but to calibrate colours you'll need a high quality light source (real daylight is quite good, but varies a lot). At this point, a cheap calibrator is probably easier and far more accurate.