No matter what type of camera you choose, it’s pretty useless without a memory card inside of it. A memory card is a small, portable storage device that slips into your camera and records the photos you take. You can think of the memory card as the film of the digital age, but unlike film, you can reformat it and use it over and over!

Many different types of memory cards exist, and the kind of camera you have ultimately dictates which type you can use. Most CDCs use SD (secure digital) memory cards, whereas most digital SLRs use CF (compact flash) memory cards.

And to make things even more confusing, Sony has its own proprietary type of memory card, which it dubs a memory stick. To determine what type of memory card media your own camera accepts, be sure to check your user manual.

When you start shopping for a memory card, you may be alarmed by the huge discrepancy in pricing, which can literally span from ten bucks to hundreds of dollars. Two main factors affect the cost of a memory card:

  • Rate speed: The speed of a memory card (expressed in megabytes/second) indicates how quickly the card can save a photo and be ready to receive the next one. When photographing dogs, a memory card’s rate speed is of particular importance, but you don’t need to go overboard, either.

    Memory cards with a rate speed of 30MB/second should be sufficient. The rate speed directly correlates to the price tag; the faster the card, the more expensive it is.

  • Storage capacity: The storage capacity of a memory card indicates the amount of space it has. The number of photos a memory card can store is dictated by how large your camera files typically are. You can do your own rough calculations by turning the GB (gigabyte) number into MBs (megabytes).

    Simply multiply the memory card’s GB number by 1,000 and divide by your camera’s typical file size. Refer to your camera manual if you’re unsure of your camera’s typical file size. This number varies widely depending on your chosen file format. For example, the size of a photo taken in the RAW file format is much larger than the size of a photo taken in the JPEG file format.

    If your camera produces photos of 8MB in size, then a 4GB memory card will hold approximately 500 photos (4 x 1,000 = 4,000 / 8 = 500), whereas an 8GB memory card will hold approximately 1,000 photos. Just as rate speed correlates to the price of the memory card, so too does storage capacity; the larger the storage size, the more expensive the card.

When you transfer photos to your computer, you should format the memory card before you use it again. Formatting a memory card permanently deletes all the data that was previously on it, so you start out again with a clean state.

Formatting your memory cards is a good habit to get into, as opposed to simply deleting images one by one or in batches, because when you merely delete an image from your memory card, you run the risk of leaving small bits of data behind that eventually clog up your memory card. The process of formatting a memory card is camera-dependent, but the option usually lies within your camera’s tools menu.