Buying a new memory card for your camera? Watch this video first

Lexar Silver Pro SDXC card.

Memory cards, particularly SD cards, are possibly the most confusing sector of camera tech on the market. Sure, they're everywhere, so getting hold of one is easy. But buying the right memory card for your camera and your shooting needs? That's quite a minefield. Capacity, capacity class, numerous speed classes and measurement systems, price per gigabyte, manufacturer reputability: with so much to consider, you'd be entirely forgiven for just selecting the largest capacity you can afford, sorting by price=lowest, then blindly buying whatever comes out top.

1. Brand 2. Position in range 3. Capacity 4. Type 5. Speed 6. Speed Class 7. UHS Class 8. UHS Bus IF product family 9. Video Speed Class

But help is at hand. For staters, we have our own handy guide explaining the myriad of confusing numbers and symbols found on an SD card. But, though it pains me to say it, YouTuber Wolf Amri has done an even better job of making sense of the SD card headache in this comprehensive yet totally accessible video guide.

The take-home really comes down to buying a card that will let your camera run at its best - whether that be exceeding its maximum video capture bit rate, or the data rate when burst shooting stills - but not going over the top and splashing out on a card that's so fast your camera won't ever make use of the excess speed.

A UHS-II card (right) will likely be faster than a UHS-I card (left), but only if your camera supports UHS-II cards

Of course, there's always an argument for just buying the fastest, largest card you can afford, so you stay futureproofed for when you get a camera that can make use of the card's full performance. While there's nothing inherently wrong with this approach, by the time you upgrade camera in a few years, you'd likely be able to buy a card of equivalent or even better performance for significantly less money.

The excess/unused performance issue becomes particularly prevalent when we look at CFexpress cards.

(Image credit: Pergear)

While SD cards vary hugely in performance, with the cheapest, slowest cards able to noticeably bottleneck the performance of high-end cameras, CFexpress cards are very different. Whether Type A or B, you'll be very hard pressed to find one which isn't fast enough to exceed the maximum possible image or video recording requirements of your camera. The latest CFexpress 4.0 speed standard for Type A and B cards is so fast that, in the case of Type B cards, not only will your current camera not even come close to exploiting its full speed, chances are even cameras released in the next 2-3 years won't either. CFexpress 4.0 Type B cards really are that quick!

With write speeds of up to 3300MB/s, this Lexar CFexpress Type B card far exceeds the maximum speed requirement of any current consumer camera (Image credit: Lexar)

So with Black Friday fast approaching, by all means make the most of those lowest-ever prices, but don't get too carried away: there's no point in spending extra on a memory card that's simply too fast for your camera.