Canon EOS R3 Advanced User's Manual page 203

* 3: [1/250-1/60sec. auto] (
[Mechanical].
* 4: [1/250 sec. (fixed)] (
[Mechanical].
Caution
High-speed sync is not available in [ ] or [
*1*4
(fixed)] .
Shutter speed is set to 1/8000 when [
[High-speed synchronization] is selected with a shutter speed of 1/8000 sec. or
faster.
) when set to [Elec. 1st-curtain] or [1/200-1/60sec. auto] (
) when set to [Elec. 1st-curtain] or [1/200 sec. (fixed)] (
: Shutter mode] is [Electronic] and
203
] mode when set to [1/180 sec.
) for
) for