Nikon D5500 - Manual (Page 167)

143 P, S, A, and M Modes
4
Select Yes.
The menu shown at right will be
displayed; highlight Yes and press
J.
The camera will enter preset
measurement mode.
When the camera is ready to measure
white balance, a flashing
D (L) will
appear in the viewfinder and
information display.
5
Measure white balance.
Before the indicators stop flashing,
frame the reference object so that it
fills the viewfinder and press the
shutter-release button all the way down. No photograph will
be recorded; white balance can be measured accurately even
when the camera is not in focus.