Everything You Ever Needed to Know About SD and Compact Flash Cards

Ever thought about buying a brand new SD or Compact Flash card for your camera phone or DSLR right before you go on safari? Sure you have. It’s a heady experience; there are so many types out there that the average storefront peon likely won’t be much help. Not to worry. SanDisk actually makes the cards, so they’re here to help you figure out exactly what you need.

Secure Digital

First up are Secure Digital cards, which you’ll normally regard as SD, miniSD, and microSD (we’ll be focusing on SD and microSD for this discussion). SD and microSD cards are remarkably versatile little pieces of storage, since they can interface with so much of your digital life, including your smartphone. But, if you’re shopping before your next big trip, you’ll need to think for a minute about card type and speed class.

Secure Digital cards are broken down into three types:

  • SDSC, or SD Standard-Capacity
  • SDHC, or SD High-Capacity
  • SDXC, or SD eXtended-Capacity

These are basically shorthand for how much storage you’re actually getting on the card. SDSC cards have a maximum capacity of 2GB, SDHC cards range between 4GB and 32GB, and SDXC cards range from greater-than 32GB up to 2TB (though the highest capacity you’ll see out in the wild these days will be 128GB). As a rule of thumb, the higher the capacity, the more expensive they’ll be.

Deeper down the rabbit hole are speed classes. Speed classes indicate how fast data can be written to the card and cater especially to video. They break down as follows:

  • Class 2: 2MB/s minimum write speed for SD video
  • Class 4: 4MB/s minimum write speed for HD video
  • Class 6: 6MB/s minimum write speed for HD video
  • Class 10: 10MB/s minimum write speed for HD video and stills
  • Ultra High Speed Class 1 (or UHS-1): 10MB/s minimum write speed for HD and real-time broadcast

Write speed is really how fast the card can record an image or video to the card, so the higher the write speed, the faster it can process what you’re shooting. In the real world, that translates to you being able to take pics of rhinos or cityscapes in quicker succession.

Also, keep in mind that you’ll usually see a card’s maximum write speed on its packaging, which should make things easier for you. For instance, a 128GB SanDisk’s Extreme SDXC UHS-I card has a write speed of 45MB/s. Translation: you can now take lots of super quick shots of that lion chasing you. Good luck!

CompactFlash

CompactFlash, or CF, is definitely for the professionals. Not because they’re better than their SD cousins — many DSLRs support SD cards by now, and both formats support those gorgeous HD videos you’ll be taking. CF cards, however, are beefier and more durable, making them a great choice if you’re out in rougher conditions.

For instance, the SanDisk Extreme Pro CompactFlash card can withstand temperatures as low as -13 degrees and as high as 185 degrees. Why you’d want to be in such conditions is another matter entirely, but you can trust your CompactFlash card will survive...even if you don’t.

Many higher-end CompactFlash cards are also based on UDMA, or Ultra Direct Memory Access, technology. That means higher transfer rates to and from the card. Said cards can have eight different modes for data transfer, from 0 to 7. UDMA 7 cards like the Extreme Pro have write speeds of up to 100MB/s. That translates to super fast performance when you’re snapping photos and shooting video.

The only disadvantage here is that you won’t be able to stick one in your smartphone.

What’s Right for You

It all depends on what you’re using them for.

For the average smartphone user, a microSD card with decent capacity can be a boon. However, most often you don’t need to worry about write speed since your device’s processor will be doing most of the heavy lifting when it comes to processing images and video. With that in mind, a 32GB SanDisk microSDHC card wouldn’t steer you wrong.

When it comes to your point-and-shoots, Micro Four Thirds cameras, and DSLRs, always pay attention to what your camera manufacturer recommends when it comes to memory cards. Cameras like the Olympus E-PL5, for example, work best with speed class 6 or higher. Beyond that, your shooting style will dictate your needs: if you shoot fast and often, higher capacity cards will be your bread and butter; if you’re more sparing with your shots, save money and shell out for less space.

If you’re opting for a CompactFlash card, you’re more than likely a professional photographer. If you plan on saving lots of RAW files taken in burst mode in the middle of the Gobi desert, this format is your go-to.

Now you're fit to find the right storage you need before your next big trip. Wanna know more? Click here to see what SanDisk has to offer for your adventures.