This technical note applies to you only if you are a Windows user shooting with a Leaf Digital Back and want to use 64gb CF cards.
Windows cannot properly use the FAT32 format for drives larger than 32gb. Since Leaf recommends you format any given CF card once in a computer prior to using it with a Leaf back this creates an annoyance. The easiest solution is to either not buy cards larger than 32gb or to format larger cards. However you can also use a bought/borrowed/stolen Mac which has no problem with formatting large disks in FAT 32 – you only need to format it once when you first buy it (assuming you only use it in the Leaf).
Failure to properly format a card prior to using it in a Leaf Digital Back, especially very high capacity cards, can, in rare cases, result in black lines or corruption lines in your raws when shooting to that CF card. So if ever notice such a thing please follow the steps here: Formatting a CF Card for Use in a Leaf Digital Back.