I have a Canon 7D (original model). I have a 16GB and 64GB CF Card formatted in FAT32 format. When I attempt to record a movie, I see that the maximum allowed time is 29:59, per US import restrictions. However, I'm finding that I can only record around 12 minutes of actual footage before the camera ends the recording. Looking on disk, I see this is near the 4GB limit of a 32-bit integer. I don't recall if this is a limitation of the FAT32 file system or not off the top of my head. In any event, is there a way I can get my camera to record more than 12 minutes of video?

Would another file system format solve the problem? If so which ones work with the camera? (NTFS?) And if there are other formats that don't show this symptom, how can I format the card using macOS Catalina (10.15)?

  • \$\begingroup\$ You might have better luck asking this (or finding an existing question that already answers it at Video SE \$\endgroup\$
    – Michael C
    Commented Sep 6, 2020 at 19:34
  • \$\begingroup\$ That's a good point. Can it be migrated? I've flagged for a moderator to do so. \$\endgroup\$ Commented Sep 6, 2020 at 19:36
  • \$\begingroup\$ With no recollection of specific models, I remember some cameras automatically splitting long videos over multiple files. \$\endgroup\$ Commented Sep 7, 2020 at 6:25
  • \$\begingroup\$ Relevant: photo.stackexchange.com/questions/34811/… \$\endgroup\$ Commented Sep 7, 2020 at 6:27
  • \$\begingroup\$ For related discussion around recording length limitations, see this question: photo.stackexchange.com/questions/14563/… This does not directly answer your question but offers some background around the limitations, hence why only posted here as a comment. I appreciate you do want to actually record beyond 4Gb and myself would share any frustration with regard to that. \$\endgroup\$ Commented Sep 7, 2020 at 13:17

2 Answers 2


There is an alternative solution, which is to side-load the Magic Lantern firmware. I believe the process is:

  1. Format the card as ExFat
  2. Copy the Magic Lantern install files to the card
  3. Insert the card into the camera, and run a firmware update
  4. Boot the camera

No warranties implied or given. ML stays on the SD card, so if you swap the card out I believe you can run the stock firmware.

  • \$\begingroup\$ Thanks! I completely forgot about this option. I'll give it a try and see how it works. \$\endgroup\$ Commented Sep 9, 2020 at 17:58
  • \$\begingroup\$ @user1118321 how did you get on? \$\endgroup\$ Commented Nov 3, 2020 at 14:57
  • \$\begingroup\$ I downloaded MagicLantern but before I got around to installing it, I found an old iPhone I had lying around. It turns out to be a way better video camera than my DSLR. It can film at 120fps (which is useful because I'm filming hummingbirds), it's very compact, and it has no limit (other than disk space) for how long of a movie it can film. I ended up also putting my current iPhone to work for the same purpose, with the downside that I end up not being able to use my phone while filming. But it does 4Kp60, which makes cropping to 1080 very nice! \$\endgroup\$ Commented Nov 21, 2020 at 23:45

The maximum file size on FAT32 is 4GB-1. I'm not familiar with the original 7D (I have a 7D II), but unless the firmware is programmed to record to multiple files, switching to a new file automatically when you hit the 4GB-1 limit, that's going to be your limit. Perhaps recording in one of the lower resolutions will allow you to go longer time-wise, but the file size limitation is still there.

Due to the limitations of firmware, it's unlikely that your camera will understand any alternative file systems. I would think that, if it did, it would give you the option of which to use when you select "Format card". Maybe some really high end ones can support multiple file system types, or maybe just to the extent that ExFAT is backwards-compatible with FAT32 (which is not a lot)...

  • 5
    \$\begingroup\$ ExFAT is not really backwards compatible: A FAT32 device can't read/write ExFAT. A device that can handle ExFAT usually is also able to handle FAT and FAT32, but that is also not a hard requirement. \$\endgroup\$
    – Tonny
    Commented Sep 7, 2020 at 10:04

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