Nikon D500 User Manual page 325

e Bracketing/flash
e1 Flash sync speed
1/250 s (Auto FP)
1/250 s
1/200 s
1/160 s
1/125 s
1/100 s
1/80 s
1/60 s
A
Fixing Shutter Speed at the Flash Sync Speed Limit
To fix shutter speed at the sync speed limit in shutter-priority auto or
manual exposure modes, select the next shutter speed after the
slowest possible shutter speed (30 s or %). An X (flash sync indicator)
will be displayed in the viewfinder and control panel.
A
Auto FP High-Speed Sync
Auto FP high-speed sync allows the flash to be used at the highest
shutter speed supported by the camera, making it possible to choose
the maximum aperture for reduced depth of field even when the
subject is backlit in bright sunlight. The information display flash
mode indicator shows "FP" when auto FP high-speed sync is active.
Choose a flash sync speed.
(defaults to 1/250 s)
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