Yes, the Canon EOS R3 is compatible with the Sony SF-G Tough 128GB.
Canon EOS R3 Slot 2 accepts SD UHS-II. Sony SF-G Tough writes at 299 MB/s (V90) — meets all SD-recordable modes on the R3 including 4K 29.97fps ALL-I (requires V60) and Full HD 239fps slow-motion (requires V90).
“[200 MB/s or higher] Video Speed Class V90 or higher”
Last verified:
Confidence: inferred