topic Re: EOS 5D MK IV CF cards in EOS DSLR & Mirrorless Cameras

CF card shows as full in EOS 5D Mark IV but OK in 7D and 7D Mark II

Spiceman987 — Tue, 09 Sep 2025 17:53:43 GMT

I have an EOS 5d MK IV and 7d MK 2. I have been using CF cards in my 7d with no issues.

However when I use a CanonFC-32MH 32GB (manufactured by Sandisk) in my 5d MK IV, I take 1 still image and it shows the card as full.

The card works fine in the 7d and also a 5d MK 2. I have formated it in the camera and also via a card reader on my laptop running Win 11. I use Sandisk and Kingston CF cards (4GB to 16GB) in the MK IV and 7d, with no issues.

I have no problems using SD cards in any of my cameras.

Does anybody have any suggestions why I have the issues only with with these Canon CF cards?

Re: EOS 5D MK IV CF cards

shadowsports — Sun, 07 Sep 2025 15:47:24 GMT

Greetings,

If you are referring to the FC-32MH, that is a 32 MB card not 32 GB.

Re: EOS 5D MK IV CF cards

Spiceman987 — Sun, 07 Sep 2025 16:08:44 GMT

OK, I was told it was 32GB! That explains why when I move to lower quality images they are stored.

Many thanks,

Re: EOS 5D MK IV CF cards

deebatman316 — Sun, 07 Sep 2025 16:43:23 GMT

I would use at least a 32GB CF Card for your camera. Anything under that is more than likely not enough space. Or the write speed will be very slow. I use 4GB CF Cards in my old EOS 40D. It would take thousands of images before being full. Older cameras have hardware limitations. So larger CF Cards may not be compatible. With a high megapixel camera such as the EOS 5D Mark IV you would only get about 100 images before being full.