Infrablue white balance
White balance can be critical to getting good results with infrablue converted cameras. Many Canon Powershots allow custom white balance. This option is sometimes available only when the camera is in Program Mode, not an auto mode or auto preset.
To custom white balance an infrablue Powershot (after removal of the internal IR block filter and with an infrablue filter in place):
- Press "Func Set" (Function Set).
- Scroll (up or down) to the white balance icon.
- Scroll (left or right) to the custom white balance icon.
- A message will display indicating which button to press to set a custom white balance.
- Point the camera at a surface of a color that you want the camera to think is light gray, and fill the frame with that color. A medium rich blue (between sky blue and navy blue) seems to work well with many of the common infrablue filters that have been tested (see below). Some evidence suggests that the white balance surface should not be in direct sunlight. Good results have been obtained with the blue surface under a clear blue sky but not in the sun. See: http://publiclab.org/notes/cfastie/07-17-2013/balancing-act
- Press the designated button.
- Press Func Set to return to camera mode.
When custom white balance is done properly, infrablue photos of healthy plants (in sun or shade) appear orangey yellow. When custom white balance is not done properly, infrablue photos of plants appear gray. When custom white balance is not done, infrablue photos appear pink.
A blue origami paper that has worked well for white balancing a CCD Powershot with Rosco #74, #2007, and #2008 filters.
More testing is needed to determine the best white balance process for different combinations of cameras and filters. Not all blue surfaces will reflect the same proportion of visible and infrared light, so some colors will work better than others. Add your observations here or at the infrared forum: https://groups.google.com/forum/#!forum/plots-infrared