Canon EOS R3 Advanced User's Manual page 347

Shutter Speed
Available shutter speeds in [
specified movie recording quality.
Frame Rate
Normal Movie Recording
] and [
–
1/4000–1/8
] mode vary depending on the frame rate of your
Shutter Speed (Sec.)
High Frame Rate Movie
Recording
1/4000–1/125
1/4000–1/100
–
347
HDR Movie Recording
–
[ ] 1/4000–1/60
[ ] 1/1000–1/60
[ ] 1/4000–1/50
[ ] 1/1000–1/50
–