Canon EOS R5 C VR Creator Kit with RF 5.2mm f/2.8 Dual Fisheye Lens - Manual (Page 116)

BULB: Long (Bulb) Exposures
Bulb Timer
In this mode, the shutter stays open as long as you hold down the shutter button completely,
and closes when you let go of the shutter button. Use bulb exposures for night scenes,
fireworks, astrophotography, and other subjects requiring long exposures.
1.
Set the shooting mode to [ ].
Press the < > button, then turn the < > dial to select
[ ].
2.
Set the desired aperture value.
Turn the < > dial to set it.
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