Back in the day, people paid attention to what type of film they bought for their cameras. It mattered. Now that film has been replaced by memory cards, it’s still important to invest care and know-how into buying the DSLR memory card that suits you best.
You have the freedom to choose your own card from an increasingly diverse range of options made by world-class manufacturers such as SanDisk and Lexar. Your choice will have a significant impact on the quality of your images and how much enjoyment you get out of owning a DLSR camera.
Figuring out formats
Before choosing a DSLR memory card, check which memory card formats your camera supports. Remember the old format war between VHS and Betamax video players? Unfortunately, a similar war broke out between DSLR memory card manufacturers. Another story for another time, perhaps. For now, be aware that two dominant formats have emerged in recent years: CompactFlash (CF) and – to a greater extent – Secure Digital (SD). The chances are that if you buy an entry-level or mid-range DSLR from a reputable brand such as Canon or Nikon, it will support SD memory cards. Many high-end, professional-level DSLRs support CF cards, which are larger and thicker than SD cards.
Although they have large capacities and fast speed ratings, CF cards are relatively expensive and may even be too powerful for mainstream amateur photographers. So, for now, let’s focus on the popular SD format. There are three types of SD memory card: the original SD cards, SD High Capacity (SDHC) cards and the newer SD eXtended Capacity (SDXC) cards. We would recommend that you give careful consideration to purchasing an SDHC memory card for your DSLR – assuming it is new enough to support this format.
Storage capacity: is bigger better?
After format, the next factor to consider is the memory card’s storage capacity. Obviously, it makes sense to buy as much capacity as you can afford. If you’re a casual point-and-shoot photographer, you can probably get by with a 4GB SDHC card. Typically, one of these cards will hold up to 1 200 JPEG images in a 10 mega pixel DLSR. That’s a lot of images and there is really no point in paying for more storage capacity.
If you are an advanced user who aims to do more with your DSLR than point and shoot, then look for an SDHC card with at least 16GB of storage. At this spec, you will be able to store around 5 000 images in a 10 mega pixel DSLR. More importantly, you will be able to store larger RAW files on your camera before you need to clear space by downloading them onto your computer.
Reading and writing speeds
This brings us to the final selection factors: your memory card’s reading and writing speeds. The writing speed applies to how quickly your camera can write data to your memory card when taking photographs. The reading speed applies to how quickly your camera can handle data when you are viewing images on your camera or transferring them to your computer.
SD, SDHC and SDXC cards measure speed by class. A Class 4 speed rating, for example, indicates that the memory card transfers data at a minimum speed of 4MBps. A Class 6 speed rating, meanwhile, indicates that the memory card transfers data at a minimum speed of 6MBps. And so on.
As a rough guide, we would recommend that a Class 4 speed rating is ideal for casual snappers; more advanced photographers should consider a Class 6 speed rating or higher; while a Class 10 SDHC card is for advanced photographers who need to push their DSLRs and their creative abilities to the limit.
Ultimately, however, the choice is entirely yours!