Nikon Autofocus Speedlight SB-24 - Manual (Page 27)

LIGHTING MANIPULATION
Bounce flash; can be considered a compensation
method since it offers variation to the exposure and
augments available light; light may be bounced off
various surfaces to create different results.
Multiple flash: using more than one flash to create
specific lighting patterns on the subject. May be used
either with available light, or to obscure (overpower) the
effects of available light.
Diffusers: devices placed in front of a camera lens to
soften a lighting effect or placed over each flash unit to
modify the quality of the light source.
Indirect flash: removing the flash from the camera and
holding it to the side, above or from below the subject to
create distinctly different lighting effects. This requires a
special extension cord which allows you to maintain
automatic control.