Canon EOS 1D - Manual (Page 146)

146
k Shooting Movies
About the ISO speed during manual exposure
The ISO speed can be set to [AUTO] (A) or within ISO 100-12800 in
1/3-stop increments.
If the ISO speed is set to [AUTO] (A), the ISO speed will be set
automatically within ISO 100-12800. (The [8C.Fn I -3: Set ISO
speed range] (p.208) setting will not take effect.) Movie shooting as
in aperture-priority AE mode (fixed aperture, standard exposure) is
then possible.
If [Highest ISO speed] is set to [H1] (ISO 25600), [H2] (ISO 51200),
or [H3] (ISO 102400) in [8C.Fn I -3: Set ISO speed range], the
ISO speed can be set manually within the expanded range up to the
upper limit. Also, if the ISO speed range has been set to a narrower
range than the default, you can set the ISO speed within the
narrower range.
Even if [Lowest ISO speed] has been set to [L] (ISO 50) in [8C.Fn
I -3: Set ISO speed range], [L] cannot be selected when you set the
ISO speed.
If [8C.Fn II -3: Highlight tone priority] (p.215) is set to [1: Enable],
the settable ISO speed range will start from ISO 200.
COP
Y