Canon EOS 80D - Manual (Page 204)

k Shooting Movies
202
ISO Speed During Manual Exposure Shooting
 With [Auto] (A), the ISO speed will be set automatically within ISO
100 - ISO 12800. In [Range for movies] under [z2: ISO speed
settings], if you set [Maximum] to [H(25600)], the automatic setting
range will be expanded to H (equivalent to ISO 25600). Even if you
set [Minimum] to ISO 200 or higher and [Maximum] to ISO 3200 or
lower, the range will be set within ISO 100 - ISO 6400 automatically.
 You can set the ISO speed manually within ISO 100 - ISO 12800 in
1/3-stop increments. In [Range for movies] under [z2: ISO speed
settings], if you set [Maximum] to [H(25600)], the automatic setting
range will be expanded to H (equivalent to ISO 25600).
 If [z3: Highlight tone priority] is set to [Enable] (p.147), the ISO
speed will be ISO 200 - ISO 12800.
 Under [z2: ISO speed settings], [Auto range] and [Min. shutter
spd.] cannot be set for movie shooting.
 Since shooting a movie at ISO 16000 may result in much noise, it is
designated as an expanded ISO speed (displayed as “H”).
 When switching from still photo shooting to movie shooting, check the
ISO speed settings before shooting movies.
 Changing the shutter speed or aperture during movie shooting is not
recommended since the changes in the exposure will be recorded.
 When shooting a movie of a moving subject, a shutter speed within
approx. 1/30 sec. to 1/125 sec. is recommended. The faster the shutter
speed, the less smooth the subject’s movement will look.
 If you change the shutter speed while shooting under fluorescent or LED
lighting, image flicker may be recorded.
 Under [8C.FnIII-4: Custom Controls], if [s: Expo comp (hold btn,
turn S)] is set, you can set exposure compensation while ISO Auto is
set.
 When ISO Auto is set, you can press the <A> button to lock the ISO speed.
 If you press the <A> button and recompose the shot, you can see the
exposure level difference on the exposure level indicator (p.203)
compared to when the <A> button is pressed.
 By pressing the <B> button, you can display the histogram.