What to look for in a SD card
All those icons and numbers do actually mean something
Lock Quite simply, this lets you lock the card so you don’t accidentally delete important shots.
SDXC logo This indicates that the card conforms to the newest SDXC format. Less expensive cards will often be the older SDHC type. As long as the speed and capacity are what you need (and your camera can use both types), the difference is not that important.
UHS-II This ‘II’ icon indicates the card is a faster UHS-II type, with an extra row of electrical contacts on the back. UHS-II cards are faster, but not all cameras have UHS-II compatible memory card slots to take advantage of this extra speed.
Maker’s name and product range Memory card makers typically create several SD card minibrands for different types of user. Here, ‘Professional’ is one of Lexar’s sub-brands, and indicates its likely audience, not specific performance figures.
microSD cards
This is a much smaller SD card variant that’s used extensively in action cams and 360 cameras, which still need the same high capacities and data speeds.
Card capacity
This is the easy one! Card capacity is quoted in gigabytes (GB). Within any maker’s range or sub-range (like Lexar Professional), the cost of a card is generally roughly proportional to its capacity.
UHS-II double contacts On the back of UHS-II cards, you’ll see two rows of electrical contacts, not one. This offers higher data transfer speeds, which is especially relevant to videographers.
V90, U3 and Class 10 rating This indicates the memory card’s minimum sustained write speed, which is crucial for video recording. U3 is suitable for recording 4K video and is a step up from the common Class 10/U1 rating. V90 is the highest current standard at a minimum 90MB/s, suitable for 8K video.
Maximum card speed
The video Class rating tells you the card’s minimum sustained speed, while this one is simply its maximum (not necessarily sustained). It’s quoted in megabytes per second (MBps) and, with Lexar cards, also as a ‘x’ rating.
High-speed card readers Regular memory card slots and readers may not be optimised for ultra-high data transfer speeds, so Lexar ships a dedicated card reader for its Professional memory cards.