Canon EOS R5C Manual page 117

3.
Take the picture.
Caution
Do not point the camera toward an intense light source, such as the sun or an
intense artificial light source. Doing so may damage the image sensor or the
camera's internal components.
Long bulb exposures produce more noise in the image than usual.
ISO 400 is used when the camera is set to ISO Auto.
When shooting bulb exposures with the self-timer instead of the bulb timer, keep
pressing the shutter button completely (for the self-timer time and bulb exposure
time).
Note
You can reduce the noise generated during long exposures by using [
exp. noise reduction] (
Using a tripod and the bulb timer is recommended for bulb exposures.
You can also shoot bulb exposures with Remote Switch TC-80N3 (sold
separately,
You can also use Remote Controller RC-6 or Wireless Remote Control BR-E1
(both sold separately) for bulb exposures. When you press the remote controller's
release (transmit) button, the bulb exposure will start immediately or 2 sec. later.
Press the button again to stop the bulb exposure.
Bulb Timer
You can set the exposure time for bulb exposures in advance. This feature eliminates the
need to keep holding down the shutter button during bulb exposures, which can reduce
camera shake.
Note that the bulb timer can only be set and will only take effect in [
mode.
The exposure will continue for as long as you keep the shutter button
pressed completely.
Elapsed exposure time is displayed on the LCD panel.
).
).
117
: Long
] (bulb exposure)