Canon EOS R6 Mark II Mirrorless Camera with 24-105mm f/4-7.1 Lens - Manual (Page 221)

Slow Synchro
You can set the flash-sync speed for flash photography in < P > or < Av > mode. Note that the
maximum flash synchronization speed varies depending on the [ : Shutter mode ] setting.
It is 1/250 sec. when set to [ Elec. 1st-curtain ] and 1/200 sec. when set to [ Mechanical ].
1/250-30sec. auto ( )* 1
Shutter speed is automatically set in the following range to suit brightness. High-speed
sync is also possible.
[ : Shutter mode] Setting Shutter Speed
Mechanical 1/200–30 sec.
Elec. 1st-curtain 1/250–30 sec.
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