Canon ICAM62B Advanced User's Manual page 236

Movie Mode
Recording with [Movie manual exp.]
You can manually set the shutter speed, aperture, and ISO speed for movie
recording.
236
1
Set the Mode dial to <k>.
2
Press <0>.
3
Select [M].
Use the < W > < X > keys to select
z
[M (Movie manual exp.)], then press
< 0 >.
4
Set the ISO speed.
Press the <B> button.
z
Use the < Y > < Z > keys to set it.
z