Canon EOS 5D MARK IV Instruction Manual page 340

k Shooting Movies
Notes for <A>, <d>, <s>, <f>, and <F> Modes
In the <A> mode, the scene icon for the scene detected by the camera
is displayed on the upper left of the screen (p.339).
You can lock the exposure (AE lock) by pressing the <A> button
(except in the A mode, p.259). After applying AE lock during movie
shooting, you can cancel it by pressing the <S> button. (AE lock setting
is retained until you press the <S> button.)
You can set exposure compensation up to ±3 stops by setting the
<R> switch to the left and turning the <5> dial (except in the
<A> mode).
In the <A>, <d>, and <F> modes, the ISO speed, shutter speed, and
aperture will not be recorded in the movie's Exif information.
During movie shooting in the <A>, <d>, <s>, <f>, or <F>
modes, this camera supports the Speedlite's function to turn on the LED
light automatically in low-light conditions. (However, no icon indicating
that the LED light is ON is displayed on the information display screen
illustrated on page 344.) For details, refer to the Instruction Manual of the
EX-series Speedlite equipped with an LED light.
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