Nikon D800 User Manual (en)

The Flash Sync Mode Display
M does not appear in the control panel flash sync mode display when – – 
is selected for Built-in flash > Mode.
Flash Compensation
The flash compensation value selected with the 
M (Y) button and sub-
command dial is added to the flash compensation values selected for 
the built-in flash, group A, and group B in the Commander mode 
menu. A 
Y icon is displayed in the control panel and viewfinder when 
a flash compensation value other than ±0 is selected for Built-in flash > 
TTL. The 
Y icon flashes when the built-in flash is in mode M.
Commander Mode
Position the sensor windows on the remote flash units to pick up the 
light from the built-in flash (particular care is required if the camera is 
not mounted on a tripod). Be sure that direct light or strong reflections 
from the remote flash units do not enter the camera lens (in TTL mode) 
or the photocells on the remote flash units (AA mode), as this may 
interfere with exposure. To prevent timing flashes emitted by the built-
in flash from appearing in photographs taken at short range, choose 
low ISO sensitivities or small apertures (large f-numbers) or use an 
optional SG-3IR infrared panel for the built-in flash. An SG-3IR is 
required for best results with rear-curtain sync, which produces brighter 
timing flashes. After positioning the remote flash units, take a test shot 
and view the results in the camera monitor.
Although there is no limit on the number of remote flash units that may 
be used, the practical maximum is three. With more than this number, 
the light emitted by the remote flash units will interfere with