Camera Color Temperature Calibration Procedure

From apertus wiki
Jump to: navigation, search

1 Requied Tools

  • Redhead Light Redhead 800w.jpg
  • Colortemperature Meter
  • Calibrated Colorchart

2 Procedure

There are several ways to move the white point through XYZ and transform it. XYZ scaling (worst - aka Wrong Von Kries), Von Kries, and Bradford Bradford is the accepted best of breed white balance transform currently.

There are basically three points white balance enters into things:

  1. When shooting. In this case, tungsten is probably the only decent option due to full spectrum with no spikes.
  2. During a PCS conversion. If we use Argyll or any other ICC based software, there is always a D50 implied PCS, so a Bradford color transform happens from source photographed white to PCS.
  3. Destination white. Another Bradford here.

Basically it would be along these lines:

  1. Show up at rental house for redhead lamp. Measure color temp using their meter. Note it.
  2. Slap half CTB on the doors, measure temp. Should be around 4300k. Note it.
  3. Slap full CTB on the doors, measure temp and note.
  4. Take lamp home, using diffusion and color as per tests above, shoot:
    1. One at native tungsten output.
    2. One with half CTB.
    3. One with full CTB.
    4. Another set if there are white balance settings on the sensor. One set per ballpark setting. Likely 3200, 4300, and 5500.