Canon EOS R5 C VR Creator Kit with RF 5.2mm f/2.8 Dual Fisheye Lens - Manual (Page 163)

Non-Canon Flash Units
Sync speed
The camera can synchronize with non-Canon compact flash units at up to 1/250 sec. (or
up to 1/200 sec. with [
: Shutter mode ] set to [ Mechanical ]). With large studio flash
units, the flash duration is longer than that of a compact flash unit and varies depending
on the model. Before shooting, confirm that flash sync is performed correctly by taking
some test shots at a sync speed of approx. 1/60 sec. to 1/30 sec.
Caution
Using the camera with a dedicated flash unit or flash accessory for cameras of
other manufacturers poses a risk of malfunction and even damage.
Do not attach a high-voltage flash unit to the camera's multi-function shoe. It may
not fire.
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