Canon EOS-1DX Instruction Manual page 145

Spot metering circle
Custom WB data can also be registered as follows:
1. Press the <B> button and turn the <5> dial to select <O>
(p.143).
2. Then turn the <6> dial to select the number under which the
Custom WB is to be registered.
3. Press the <J> button.
→ [ * ] will blink on the top LCD panel.
4. Follow step 4 above to photograph a solid-white object.
→ The Custom WB data will be registered under the selected number.
When a picture is taken, the registered Custom white balance will be
applied.
If the exposure of the picture differs greatly from the standard exposure,
a correct white balance might not be obtained. If [Correct WB may not
be obtained with the selected image] is displayed in step 4, go back to
step 1 and try again.
The image captured in step 4 will not be recorded to the card.
Instead of a white object, an 18% gray card can produce a more
accurate white balance.
4
Photograph a solid-white object.
The plain, white object should fill the
spot metering circle.
Focus manually and set the standard
exposure for the white object.
Any white balance setting can be set.
The Custom WB data will be
registered.
To use the Custom WB, see
"Selecting and Shooting with the
Custom WB Data" (p.147).
O Custom White Balance
145