Flash Compensation - Nikon D90 Manual

Exposure Modes
P, A
S, M
There is no " off " flash mode for exposure
modes P, A, S, or M. To turn the flash off press
it down to lock it in the closed position.

FLASH COMPENSATION

It's also possible to vary the power of the flash. You can increase or
decrease the amount of light the flash puts out by using the flash
compensation. The increased power of the flash is not enormous, but
it does provide a little extra light if the normal flash power isn't quite
enough. The D90 provides more options for decreasing the output of
the flash. Flash compensation allows you to balance the light from the
flash with the light in the rest of the scene. One of the problems with
using the flash at its normal power is that the pictures will look like
" flash pictures " : the subject ends up very brightly lit, there's often a
harsh shadow, and the background may end up very dark. Let's say
you're photographing someone outside on a sunny day. The sun is
hitting the person's face such that part of the face is brightly lit and
TIP
Flash Modes Available
After the flash fires, it must recharge before
you can take another picture using the flash.
In the viewfinder at the bottom right the flash
symbol will blink if the flash is recharging. It will
stay solid once the flash is ready to be used.
Making Pictures
TIP
57