A Digital Photography Memory Card Primer

SD, SDHC, Compact Flash, Memory Stick, miniSD, microSD, and about two dozen more anachronyms clutter the storage type definitions for your digital camera. Here’s a word or two about which you may need and why bigger is not always better.

Flash memory uses small chips to electronically store data and your camera may use any of a number of formats to store that data. You can look at your owner’s manual (I know..I know but honestly it is in there). Or you can refer to any number of online buying guides which will tell you which memory card would be the best one for your camera.

If you have a DSLR, the kind with an interchangeable lens and it’s kind of big, you probably use either a SD, SDHC, or Compact Flash card.

Now the SD and SDHC cards are almost identical but there is a difference. SD stands for Secure Digital format and it is an older technology. It has a maximum storage capacity 4 gigabytes. There are numerous manufacturers of these types of cards and each one ships formatted in a Fat32 format. If that format sounds familiar, it’s because that is the same format that was used by Windows.

SDHC is just like the SD memory cards except SDHC means Secure Digital High Capacity. These cards start at the 4GB mark and are currently available in 32GB versions.

And some companies already are coming out with the next generation of secure digital cards with capacities that can get up to 2TB.

SD cards come in different speeds, Class 2, Class 4, and Class 6.. The difference in these speeds has a direct correlation on how fast they read and write data to the memory card from your device. The fast the read/write time, the quicker your camera can unload data from its internal memory and on to the card which frees up memory for the next shot. This can lead to a faster burst of speed if you are taking photos are a very fast pace.

The same is true for Compact Flash. Compace Flash cards come in Class I, Class II, and Class III. Class III cards are the newest and fastest. Class I cards are the oldest technology and Class II is the happy medium.

The current maximum capacity for a Class III compact flash card is 64GB. These Class III cards write at 90mb/s or Class 6 speeds on an SDHC card.

These large cards are great for video. So if you have a DSLR that is capable of video, these large and fast cards are for you. However, if you have a DSLR or even a point and shoot camera, smaller is better.

Why? The answer is simple. The larger the capacity of the card the more data you are able to store on it. The more data that you store on it and this means that there is a larger risk of losing more images or data that is stored on it. So smaller is better because if a small card gets corrupted and you lose data, the fewer images or the less important data that you lose.

These same rules hold true for other memory formats. Use smaller cards, switch them out and you run less of a risk.

There is one more thing to know about digital memory cards. On each card, there is usually a switch that locks the card and prevent someone from accidentally erasing the data on it before you have had a chance to download it on to a larger capacity device, like your computer or your photo sharing service.

Just an idea….

3 thoughts on “A Digital Photography Memory Card Primer

  1. That is an interesting point. I never thought about it that way. it is a great example of that too.

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