Nikon D3100 User Manual page 170

❚❚ Long Time-Exposures (M Mode Only)
At a shutter speed of "bulb, " the shutter remains
open while the shutter-release button is held
down. This can be used for long time-exposure
photographs of moving lights, the stars, night
scenery, or fireworks. A tripod or optional MC-DC2
remote cord (0 177) is recommended to prevent
blur.
1
Ready the camera.
Mount the camera on a tripod or place it on a stable, level surface. To prevent
loss of power before the exposure is complete, use a fully charged EN-EL14
battery or an optional EH-5a AC adapter and EP-5A power connector. Note that
noise (randomly-spaced bright pixels or fog) may be present in long exposures;
before shooting, choose On for the Noise reduction option in the shooting
menu (0 134).
2
Rotate the mode dial to M.
t
3
Choose a shutter speed.
Rotate the command dial until "Bulb"
(A) appears in the viewfinder or
information display.
4
Open the shutter.
After focusing, press the shutter-release button all the way down. Keep the
shutter-release button pressed until the exposure is complete.
5
Close the shutter.
Take your finger off the shutter-release button.
A
Self-timer Mode
In self-timer mode, a shutter speed of "Bulb" is equivalent to approximately
78
Length of exposure: 35 s
Aperture: f/25
Mode dial
Command dial
1
/
10
s.