Understanding SD & Micro SD Memory Cards
Secure Digital (SD) is the most popular memory card format around. SD cards are generally used for cameras, handheld video cameras, all the way up to professional DSLRs that capture images and video. The mobile versions of SD cards are microSD cards designed for use in smartphones and tablets. They adhere to the same technical specifications as the bigger SD card most commonly seen in cameras, but as image capture devices have transformed over the years, becoming smaller and more portable, the microSD card has been adopted for use in new technologies like HD sports camcorders and aerial cameras.
Capacity: Shown in gigabytes (GB) on the front of the card. The higher the capacity, the more photos and videos you can store on the card. So if you primarily shoot still images, you might not need a memory card with a huge capacity, but if shoot a lot of video, you should choose a card with a larger capacity. These are also indicated by SD (up to 2GB storage), SDHC (from 2GB up to 32GB) and SDXC (from 32GB to 2TB).
Performance: A card’s performance is defined as the speed at which your card is able to store and download images, expressed as “write” and “read” speeds.
Write speed: Write speed is how fast images are written to a memory card inside the camera.
Read speed: Read speed is how fast images are transferred off of a memory card to a computer.
Speed Class and UHS Speed Class: SD cards have two types of speed indicators generally shown on the card. These are Speed Class (number inside a C) which designates minimum write performance. These range from Class 2 (2MB/s) to Class 10 (10MB/s) and UHS Speed Class (a number inside a U) which indicates how quickly video/images can be transferred onto the memory card. UHS-I enables maximum transfer speeds of 104MB/s while UHS-II enables maximum transfer speeds of 312MB/s. Within the UHS Speed Class there are two designations, U1 and U3, which represent minimum write speeds of 10MB/s and 30MB/s respectively. Confusingly, U1 (UHS Speed Class 1) and Class 10 refer to the same 10MB/s speed standard, so sometimes you’ll see cards that are labelled both as Class 10 and U1. UHS speeds are not seen on cards below Class 10.
Video Speed Class: This is the latest standard in class speeds which ensures a guaranteed minimum performance speed for recording video with a range from 6MB/s to 90MB/s. The fastest options – V60 (60MB/s) and V90 (90MB/s), will support 8K resolution (7680 x 4320), while V6 (6MB/s), V10 (10MB/s) and V30 (30MB/s) capture high-definition and 4K. All speed classes guarantee minimum video recording speeds to ensure smooth video playback, so actual recording performance may be even faster.
What Should I Choose?
What type of photographs/video do you plan to take?
Taking still images doesn’t necessarily require fast write speeds, whereas capturing action, sports, or video requires fast write speeds to help eliminate missed shots or dropping frames from video. If considering a UHS-II card ensure that your camera is UHS-II compliant otherwise you will be limited to the speeds of UHS-I. Next to consider is read speeds which will enable you to download your images to your computer quicker. If you opt for a card with a faster read speed ensure you invest in a good memory card reader. If your computer has a USB 3.0 port, buy a USB 3.0 reader to take advantage of the fast read speeds. This will cut down the time of transferring your files to your computer. Lastly to consider is capacity. Are you shooting video or JPG images, RAW images, or both? Video and RAW images take up more room on your card than JPG files. Therefore, you will need a larger capacity card if shooting video, RAW images, or RAW and JPG images at the same time. Remember, it’s always better to have too much storage than not enough! Buy memory cards.