White balance card & a trap for young players

[Snapper]

I took some informal portraits by a window. Before the subjects arrived I took a photo of my white balance card to use as a reference in post-processing.

The session went without a hitch, but in PP I realised I'd set the camera WB to "Auto", thus the white balance of each photo was different as the light through the window changed subtly from shot to shot. D'oh! So my WB card was valid only for the shot it was in!

Lessons:

1. Use the same pre-set WB for each shot OR
2. Use the WB card to set a custom WB.

[LiquidAir]

Or shoot RAW so the camera WB is not burned into the image.

[Terrence]

I always shoot RAW. Always. The flexibility is priceless.

[arodney]

Or shoot RAW so the camera WB is not burned into the image.

Exactly! Only ISO/Exposure play a role here.