Canon EOS-1D Mark IV - Manual (Page 141)

Shooting Movies
The Live View image can be recorded to the card as a
movie. A movie can be shot with automatic exposure or
manual exposure. The movie recording format will be
MOV.
^ Cards which can record movies
When shooting movies, use a large-capacity card with a fast
writing/reading speed. The CF card's speed should be 8MB/
sec. or higher. And the SD card should be rated SD Speed
Class 6 “
class ©” or higher.
If you use a slow-writing card when shooting movies, the movie might
not be recorded properly. And if you playback a movie on a card
having a slow reading speed, the movie might not playback properly.
To check the card's read/write speed, refer to the card
manufacturer's Web site
E|]
About Full HD 1080
Full HD 1080 indicates compatibility with High-
Definition featuring 1080 vertical pixels (scanning
lines).
FULLK}
1080
141