When you buy a new digital camera you also need a memory card, since most of the cameras are either sold without them or the one that is included is ridiculously small.

When choosing a memory card, first thing you need to do is to find out what type of card goes with your camera. There are four types that are most common, so your camera uses most likely one of the following:

  • Secure Digital (SD) – currently most widely used card. Canon, Nikon, Pentax and many other cameras use this.
  • Compact Flash (CF) – used in many digital cameras, often as a second choice. It allows bigger memory sizes and speed, but also has bigger physical measurements.
  • Memory Stick (MS) – mainly used in Sony cameras.
  • xD Picture Card (xD) – Olympus and Fujifilm digital cameras use this type.

Normally you can find the card type written near the memory card slot on the camera or in the user’s manual. If you can’t find it in neither of them, take your camera to the photo gear store and they should be able to help you.

Buying a memory card is not only about the type, the capacity of the card is also important. It determines, how many pictures the card can hold.

How to decide what size is the the right size?

For a start, think how many pictures do you usually would want to take. If you go traveling you are likely to take much more pictures than on family occasions. Size of one image file in case of .jpg format is approximately 1 MB with 5 megapixel (MP) cameras and up to 5MB in 10 MB cameras. So, 1 GB memory card can hold from 200 photos of 5 MB size to 1000 photos of 1 MB size. Considering this, 1-4 GB memory cards are enough. In case you go traveling a lot, I would suggest buying several smaller cards instead of one big card. For example it’s better to buy four 4 GB cards than one 16 GB card, so if one of cards gets damaged or lost, you won’t lose all the pictures. After all, it only takes a few moments to change a card in a camera.

Now when it comes to DSLR (digital SLR) cameras, the RAW format file is normally in the size of 10-20 MB, so, I suggest you get at least 8 GB card.

And finally, the speed of a memory card. In normal situations and with lower resolution cameras, memory card speed is not that important. It starts to matter with high megapixel cameras and if you want to make high-speed continuous shoots like photographing a moving athlete or a bird. In these cases you should consider a card that has speed rating at least 100x or SD class 15. However, if you’re using DSLR camera in RAW format and want to make continuous shoots, get the card with the highest speed rating possible.