GoPro HERO 4 Black User Manual page 37

SHUTTER
Shutter applies only to Night Photo and Night Lapse and determines
the amount of time that the shutter is open. The options for this
setting are auto (up to 2 seconds), 2, 5, 10, 15, 20 or 30 seconds. The
default setting is auto.
Settings
Auto
2 sec, 5 sec, 10 sec
20 sec
30 sec
Examples
Sunrise, sunset, dawn, dusk, twilight, night
Dawn, dusk, twilight, traffic at night, Ferris
wheel, fireworks, light painting
Night sky (with light)
Night stars, Milky Way (complete darkness)
/ Photo Mode
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