Requied Tools
- Redhead Light
- Colortemperature Meter
- Calibrated Colorchart
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:
- When shooting. In this case, tungsten is probably the only decent option due to full spectrum with no spikes.
- 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.
- Destination white. Another Bradford here.
Basically it would be along these lines:
- Show up at rental house for redhead lamp. Measure color temp using their meter. Note it.
- Slap half CTB on the doors, measure temp. Should be around 4300k. Note it.
- Slap full CTB on the doors, measure temp and note.
- Take lamp home, using diffusion and color as per tests above, shoot:
- One at native tungsten output.
- One with half CTB.
- One with full CTB.
- Another set if there are white balance settings on the sensor. One set per ballpark setting. Likely 3200, 4300, and 5500.