Canon EOS RP Advanced User Guide - Page 253

Setting the Movie Recording Size Cards that Can Record Movies For details on cards you can use for various movie recording sizes, see =585. When recording movies, use a high-capacity card with a writing/reading speed (as specified in card performance requirements) shown in the table on =585 or higher than the standard specification. Test cards by recording a few movies to make sure they can record correctly at your specified size (=249). ooFormat cards before recording 4K movies (=367). ooIf you use a slow-writing card when recording movies, the movie may not be recorded properly. Also, if you play back a movie on a card with a slow reading speed, the movie may not be played back properly. ooWhen recording movies, use high-performance cards with a writing speed sufficiently higher than the bit rate. ooWhen movies cannot be recorded normally, format the card and try again. If formatting the card does not resolve the problem, refer to the card manufacturer's website, etc. ooTo obtain better performance with the card, formatting the card with the camera before recording movies is recommended (=367). ooTo check the card's writing/reading speed, refer to the card manufacturer's website, etc. 253