Custom Setting #C3 Self Timer Delay Setting - Nikon D300 Complete Manual

Recommendations:
1. If you need more battery conservation, change the camera
to a 4-second timeout. You'll get slightly more exposures
per battery charge (assuming you work quickly and setting
the timeout lower doesn't force you to trigger the meter
more often).
2. Avoid the 30-second and longer delays, and the No limit
settings unless you have extra batteries.
3. If you use an external power source, you don't need to
worry about this setting, as the camera sets a value of No
limit as long as power is plugged into the DC In socket.
4. Sports photographers tend to like No limit (indeed, they
were the ones that asked for it in the first place). Why?
Because they don't want any lags in their camera, as it
might make the difference between getting "the moment"
and not. If the camera's metering and focusing system
goes inactive, there's a very short, but still real delay
before they come up again. Sports photographers love to
just follow action through the viewfinder and be able to
punch the shutter release at any time without worrying
about whether the camera is active or not.

Custom Setting #C3 Self Timer Delay Setting

(Self-timer delay)
The D300 allows you to set four different delay times for the
self timer (the delay time is the time between pressing the
shutter release and the shutter actually being opened for
exposure):
Two second delay
2s
Five second delay
5s
Ten second delay [default]
10s
Twenty second delay
20s
Thom Hogan's Complete Guide to the Nikon D300
V1.02
Page 546