Canon EOS 80D - Manual (Page 204)

204
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. This is called bulb exposure. Use bulb exposures for night
scenes, fireworks, the heavens, and other subjects requiring long
exposures.
1
Set the Mode Dial to <F>.
2
Set the desired aperture.
 While looking at the LCD panel, turn
the <6> or <5> dial.
3
Take the picture.
 The exposure will continue for as long
as you keep the shutter button
pressed completely.
 The elapsed exposure time will be
displayed on the LCD panel.
F
: Bulb Exposures
Elapsed exposure time
 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 exposures produce more noise than usual.
 If ISO Auto is set, the ISO speed will be ISO 400 (p.150).
 For a bulb exposure, if you use both the self-timer and mirror lockup
instead of the bulb timer, keep pressing the shutter button completely
(self-timer delay time + bulb exposure time). If you let go of the shutter
button during the self-timer countdown, there will be a shutter-release
sound, but no picture will be taken. If you use the bulb timer under the
same shooting conditions, you need not keep holding down the shutter
button completely.