Buying the right CF card for your digital camera can be difficult, well mostly confusing since there are size, type and speed considerations to wrap your head around first. Size and type are pretty straightforward. Most consumers should buy the largest capacity CompactFlash memory card within their means so they do not have to swap memory cards out constantly. There are two types of CompactFlash memory cards: Type I and Type II. The only difference between them is the height of the card. Type I CF cards are 3.3mm thick while Type II stands 5mm high. Some cameras are not compatible with Type II CF media, so this question comes down to knowing what your camera supports.