Almost every electronic device you buy today requires a memory card. But which one should you buy for your device? For the most part, almost all devices tend to use either an SD card, or a microSD card. There are a few other options, such as CompactFlash, Memory Sticks, and xD Photo cards, but SD cards have, in general, taken over the majority of the market. As such, I will only be talking about SD and microSD cards.
In looking at SD (Secure Digital) cards, the first thing to realize is there are two (actually three, but one, miniSD, is not used anymore) sizes. There is the standard size, which is larger and typically used in cameras, camcorders, and some older mobile phones. There is also a smaller microSD card, which is typically found in mobile phones, MP3 players, and tablets. You can easily tell which your device will use by the size of the slot for the card.
The next thing to look at is the capacity. There are three capacity types of SD and microSD cards – SD, SDHC, and SDXC. The letters really pertain to the different capacities. SD only comes up to 2 GB. SDHC (High Capacity) goes up to 32 GB, and SDXC (Extended Capacity) can range from 64GB to 2 TB, but currently the largest available is only 128 GB.
While the letters do only stand for the different capacities, you always want to check the documentation on your device to see if it lists SDHC or SDXC. I know I have come across several older models of cameras, after customers stated that a certain card would not work, that only take SD cards and cannot take a card larger than 2 GB. Some even state not larger than 1 GB. Always check your device’s user manual to see what is compatible.
Most current devices can take either SD or SDHC cards, and it is likely that if you have a card currently in your phone, it is really a microSDHC card. If you are looking to get a SDXC card, again be certain to check the documentation as this is a newer type of classification and not all devices will accept it.
Finally, there are different speed classifications. This really only matters when taking high resolution/high definition photos; it won’t make much of a difference in a point-and-shoot camera. But there are several classes of speed for SD and microSD cards – Class 2, Class 4, Class 6, and Class 10. For standard definition video, Class 2 is adequate. For HD quality video, you would want to look into Class 4 or Class 6. Class 10 is actually faster than any current video standard, but rather is designed for still photography taken in rapid succession. This allows the pictures to be stored more quickly to be able to capture the next image faster.
Modern cameras and devices should handle all speed classes. However, if they do not support a class, such as Class 10, they will fall back to the fastest speed it will support, such as Class 6. Again, this information should be found in your device documentation.
So, after all this information, my first advice is to check the documentation to see what your device can handle. Make sure you get the right size of card, and look into the speed you can use most effectively for what you want to do with the camera. Then, make your choice of cards based on those factors.