Canon EOS 90D Advanced User's Manual page 291

Cards that Can Record Movies
For details on cards you can use for various movie recording sizes, see
= 617.
When recording movies, use a high-capacity card with a writing/reading
speed (as specifi ed in card performance requirements) shown in the
table on = 617 or higher than the standard specifi cation. Test cards by
recording a few movies to make sure they can record correctly at your
specifi ed size ( = 288).
Format cards before recording 4K movies ( = 511).
o
If you use a slow-writing card when recording movies, the movie may not be
o
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.
When recording movies, use high-performance cards with a writing speed
o
suffi ciently higher than the bit rate.
When movies cannot be recorded normally, format the card and try again.
o
If formatting the card does not resolve the problem, refer to the card
manufacturer's website, etc.
To obtain better performance with the card, formatting the card with the
o
camera before recording movies is recommended ( = 511).
To check the card's writing/reading speed, refer to the card manufacturer's
o
website, etc.
Movie Recording Quality Settings
291