The maximum size of a movie is 4GB (about 11 minutes of video). During movie shooting, approx. 30 sec. before the movie reaches the 4 GB file size, the elapsed shooting time displayed in the movie shooting screen will start blinking. If you keep shooting the movie and the file size exceeds 4 GB, a new movie file will be created automatically and the elapsed shooting time or time code will stop blinking. When you play back the movie, you will have to play each movie file individually.
The maximum recording time of one movie clip is 29 min. 59 sec. If the movie shooting time reaches 29 min. 59 sec., the movie shooting will stop automatically. You can resume movie shooting by pressing the button. (A new movie file is recorded.)
The memory card is formatted with a FAT32 filesystem so that it's compatible with most computers. You can slip that card into any Windows, Mac, or even a Linux computer and they can all read FAT32 filesystems with nothing special to install.
But the "catch" is that the maximum size for any single file on a FAT32 filesystem is 4GB.
Unfortunately there are no filesystems which allow for larger filesizes that are included for all computers (there are... but they aren't free. Microsoft charges royalties to use NTFS. Apple charges royalties to use HFS+. ZFS is open-source ... but would probably create a lot of confusion among consumers trying to figure out how to obtain and install it and then you've got ongoing support/maintenance issues (e.g. will it still work if you upgrade your operating system version, etc.)
So... using FAT32 is probably the best answer but it does mean you have to put up with that 4GB limit.
The limit turns out not to be a problem for pro video -- pros prefer to shoot many short-scenes rather than one long-continuous scene. They also tend to use more than one camera and these are all spliced together using video editing software on a computer. Watch any professionally created video (a movie, tv show, even a commercial) and try to count the number of seconds before the scene or camera angle changes. You'll find that most times you don't get more than 10 seconds before it changes.
12/05/2023: New firmware updates are available.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.