Canon EOS 7D Mark II (G) Instruction Manual page 345

Movie Servo AF speedN
When active : [Always on] sets the AF adjustment speed to take
AF speed
* Lenses supporting slow focus transition during movie shooting
USM lenses marketed in 2009 or later and STM lenses (for example,
the EF-S18-135mm f/3.5-5.6 IS STM) support slow focus transition
during movie shooting. For details, refer to the Canon website.
If L8(59.94 fps) or 7(50.00 fps) is set, Movie Servo AF will not
function and therefore the settings above will not be available.
If [AF method] is set to [u+Tracking] or [FlexiZone - Multi], the AF
adjustment speed will be equivalent to the [Standard] setting.
You can set the Movie Servo AF's AF
speed and its operation conditions.
This function is settable when [Movie
Servo AF] is set to [Enable] and [AF
method] is set to [FlexiZone - Single].
Additionally, the function is only enabled
when using a lens compatible with slow
focus transition during movie shooting*.
effect at all times for movie shooting (before and
during movie shooting). [During shooting] sets the
AF adjustment speed to take effect only during
movie shooting.
: You can set the AF adjustment speed (focus
transition speed) to one of five levels, from standard
speed to slow, to obtain the desired effect.
3 Menu Function Settings
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