Читать книгу Canon EOS 90D For Dummies - King Julie Adair, Robert Correll - Страница 42

Again, you can use regular SD cards, which offer less than 4GB of storage space; SDHC cards (4GB–32GB); and SDXC cards (more than 32GB). Aside from card capacity, the other specification to note is card speed, which indicates how quickly data can be moved to and from the card.

Card speed is indicated in several ways. The most common spec is SD Speed Class, which rates cards with a number between 2 and 10, with 10 being the fastest. Most cards also carry another designation, UHS-I, -II, or -III; UHS (Ultra High Speed) refers to a new technology designed to boost data transmission speeds above the normal Speed Class 10 rate. The number 1, 2, or 3 inside a little U symbol tells you the UHS rating.

The 90D supports UHS-II cards, which are much faster than the I. You can opt for a UHS0I card, but you won’t get any extra speed benefits.

Some SD cards also are rated in terms of how they perform when used to record video — specifically, how many frames per second the card can handle. As with the other ratings, a higher video-speed number indicates a faster card.