How to choose your SD card

Buying an SD card is less obvious than expected: there are many features to take into account, starting with the transfer speed

Buying an SD card is one of the main doubts of photography enthusiasts. Also because over time they have evolved hand in hand with cameras. Let's see which SD card to buy according to our needs and the device we have.

The continuous evolution of SD cards in relation to cameras represents one of the main problems for the purchase. Especially for a user with not too much specific knowledge in the field. The risk is to spend more than necessary and end up buying a card that is not compatible with our device. There are different types and brands of SD cards on the market and you have to choose the one that best suits your needs. One of the aspects that should not be underestimated is definitely the storage space available. If you are a professional photographer, we recommend an SD card that allows you to take at least 400-500 images.

Type and brand

The first thing to check when buying an SD card is that it is compatible with our camera. Assuming your camera uses the SD format, it should be compatible with the two main types of cards produced today, namely SDHC (Secure Digital High Capacity) and SDXC (Secure Digital eXtended Capacity). The quickest way to check card compatibility is to look at the camera's specifications in the manual (or on the equivalent page on the manufacturer's website). There are other types of SD cards as well, and they often come in smaller variants, such as microSDXC which are usually used in smartphones, though often with SD adapters they can also be used in cameras and various card readers. As for the manufacturers among the most famous are Lexar and Sandisk. Excellent alternatives instead with Integral, Kingston, Transcend, Toshiba and Samsung. Beware of online purchases. There is a risk of buying counterfeit cards or cards containing malicious code.


The storage capacity of an SD card is certainly the feature that most of all raises the price. The storage space, more or less, also gives the card's wording its name. All cards with a capacity of 32 GB or less, in fact, are placed in the SDHC field, while cards with a size of 64 GB or more are classified as SDXC. Not surprisingly, the 16GB, 32GB and 64GB solutions are the best sellers. If we have a 12 megapixel camera that we use occasionally a 16GB card might be enough. If, on the other hand, we love videos we'll need solutions with more storage space. Photography experts also recommend buying two or three medium-sized cards instead of one large SD card. If we lose or have our card stolen, we won't lose all our work. Same thing if the card gets ruined.

Transfer Rate

Many of today's SDHC and SDXC cards are designated with a number, such as 2, 4, 6 or 10, after the name, usually surrounded by the icon of a not-quite-closed circle. This number is known as the speed class of the card and is a useful way to judge whether an SD card is suitable for any video recording or not. The numbers are derived from the MB/s measurement. As a reminder, a card with a speed class that is too high is not necessary for HD video recording. Class 10 cards are ideal for Full HD videos, but if your camera supports 4K video recording, then, we recommend a card with UHS class and stands for Ultra High Speed, and these are the new super fast SD cards. Be careful when buying these cards, because they are not compatible with all cameras. Finally, there are also Video Speed Class developed for 8K cameras.

CompactFlash or Alternative?

Not all cameras, as mentioned, use the same type of SD card. The CompactFlash format is still used by some DSLRs, while slots for the newer CFast and XQD formats have started to appear inside some newer models. Be careful because, unlike SDHC and SDXC, these do not use the same speed classes. The fastest compact flashes are UDMA 7.

Water Resistant

Depending on how we use the cards it is also important to check if they are water, dust or X-ray resistant. If we usually shoot in extreme weather conditions, such as in the desert, this is crucial. Less so if we're using the camera for an outing or a trip.