Nikon D700 - Manual (Page 151)

125
Z
4
Press the shutter-release button all the way down.
Press the shutter-release button on the camera or remote cord
all the way down. The shutter will remain open while the
shutter-release button is pressed.
5
Release the shutter-release button.
Remove your finger from the shutter-release button to record
the photograph.
A Long Time-Exposures
Nikon recommends using a fully-charged EN-EL3e battery or an optional
EH-5a or EH-5 AC adapter to prevent loss of power while the shutter is
open. Note that noise and distortion may be present in long exposures;
before shooting, choose On for the Long exp. NR option in the shooting
menu (pg. 277).
Length of exposure: 35 s
Aperture: f/25