About memory cards and main types
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| Taken by Terry Sullivan |
When it comes to understanding how digital images are created, focus is often placed on the camera’s lens and image sensor, which makes sense, as these two components have the biggest impact on image quality.
But once an image or video is captured, it will need to be stored somewhere on the device. Nowadays, the location where the image or video files are stored varies by device. For example, if you took pictures on your phone or tablet, you’ll store the media on the built-in, non-removable flash memory. However, when it comes to taking pictures or recording video on a standalone digital camera, whether it’s a point-and-shoot or an interchangeable-lens camera, like a mirrorless or reflex camera. digital menu (DSLR), you’ll save your photos and videos on a small rectangular card, called a memory card.
What is a memory card and how do you use it?
Memory cards are essentially just miniature digital data storage devices. These cards contain non-volatile flash memory inside them, which simply means that they can retain stored information or data even when they are unplugged – i.e. removed off the camera.
Memory cards come in different capacities, like computer hard drives and SSDs. Today, you can buy memory cards in capacities from 8GB to 256GB, 512GB, and even 1TB or 2TB.
The memory card is removable and reusable. So, once you’re done taking pictures, you can remove the memory card from the camera, insert it into the card slot on your laptop, desktop, tablet, or other device, and move them to memory. of the computer. Memory cards are used as temporary storage for your pictures, but don’t worry – the data stored on them won’t degrade over time.
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| An important part of working with memory cards is formatting them. This deletes old files and makes the card ready to write new data, which helps prevent problems with corrupted or unreadable data. All digital cameras have a tag format option, even if you sometimes have to ‘dive the menu’ to find it. |
To use the memory card again, you need to format it first. Here’s how: When you first insert a memory card into the camera, or when you’ve just transferred photos from the camera to your computer’s hard drive (and of course, those images are backed up, too), you’ll want to make sure you format your memory card by looking for the setting found in your digital camera’s setup menu.
Formatting a memory card does two things at once: It creates a folder on your card and deletes any existing photos or video clips on your memory card. (If you accidentally deleted your photos or video clips before transferring them, you can use file recovery software to find a way to recover them, but it’s never certain.)
There are several reasons why you might want to format the memory card on the camera, rather than on the computer or camera is different than the one you intend to use. One of the most important is compatibility: Formatting the memory card on your camera will allow most devices, including your computer or tablet, to read the card properly. If you don’t format it first – before you use it – you run the risk of not being able to access the photos or videos you’ve taken when you want to download them from the card.
Types of memory cards
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| Taken by Terry Sullivan |
Memory cards have appeared on the market as digital camera equivalents already available to consumers, but there are several different types of cards. The most important question a digital photographer needs to ask himself is: “Is this memory card compatible with my digital camera?”
You should be able to tell what memory card your camera is compatible with just by opening the card door, but if you’re unsure, you can find the answer to that question in your camera’s owner’s manual. own it or find it on the manufacturer’s website.
If you’re not happy about having to buy expensive memory cards for your expensive new camera, check out “Dealer’s Pick: It’s time for a new card. Is that a bad thing?By DPReview editor Richard Butler, who has some thoughts on the matter.)
Compare capacity and price… over time
The good news for photographers and videographers is that memory card manufacturers have continued to expand capacity and improve performance. It is interesting to note that these days, SD memory cards, the most common type on the market, offer one thousand times the storage capacity as an SD memory card from 15 years ago and for a lot less money.
Below is a list of current memory cards that are compatible with today’s digital cameras.
SD (Secure Digital)
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Secure Digital – or SD – cards are one of the most popular types of memory cards available to photographers, and they come in several different variations. SD is more of a line of memory cards than a single ‘type’, and the first SD cards were actually introduced in 1999 with a maximum capacity of 2GB. They are based on the even older MultiMediaCard (MMC) format.
All full-size versions of SD (SD, SDHC and SDXC) measure 24mm x 32mm x 2.1mm, while the microSD card (available in SDHC and SDXC types) is smaller and measures 11mm x 15mm x 2.1mm.
Here are the three current versions of SD memory cards, along with some information on each format, as well as future specifications (recently introduced by the Secure Digital Association):
- SDXC: This is the most modern variant of the Secure Digital card, with a theoretical maximum capacity of 2TB. All in all, this is the version you’ll want to reach for if you’re shooting video, as these cards have the largest capacities, currently 1TB. These cards are available in three memory card speed designations – UHS-I, UHS-II, and UHS-III. (Note: See page 2 for more about memory card speeds.)
- SDHC: Older than the SDXC specification, SDHC cards have a maximum capacity of 32 GB. They are also available in two memory card speeds — USH-I and UHS-II.
- microSDHC & microSDXC: The smaller sizes of these two SD card formats make them ideal for portable devices, such as phones, tablets, and action cams. Like the full-size SD card versions, the microSDHC card format has a maximum capacity of 32 GB and the microSDXC format has a maximum capacity of 2 TB. You can also order microSDXC cards as large as 1TB now.
- SD Express and SDUC . memory cards (Unavailable): In June 2018, the SD Association also announced specifications for a new card format—SD Express card format, which is part of SDA’s SD 7.0 specification. Furthermore, in 2020, SDA also introduces another SD specification update—Specification SD 8.0, which will allow for even faster transfer speeds. However, no memory card has hit the market yet.
CFexpress (Types B and A)
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CFexpress is a relatively new format, but it’s quickly becoming more popular – especially among higher end cameras. The CFexpress format promises to significantly increase write, read, and transfer speeds compared to previous cards. This is great news for photographers and videographers who may want to shoot everything from 8K resolution video to slow motion video to fast burst modes of stills.
There are two types of CFexpress cards available – Type A and Type B. And since nothing is simple in the world of technology or digital cameras, we’ll be discussing Class B memory cards. Firstly, because, confusingly, they were the first to be introduced – they’re also much more common.
- CFexpress Type B: When CFexpress Class B memory cards (examples pictured above) were first hit the market, many photographers were intrigued by them being the same size and fitting into the same card slots as compatible cameras. older XQD memory cards (see below for more on XQD Cards). Many cameras designed to use XQD type memory cards can accept CFexpress Type B memory cards, but this may require a firmware update.
Class B CFexpress cards have a maximum theoretical transfer rate of 2,000MB/s, although currently, 1,000 – 1,700MB/s are more common.
- CFexpress Class A: In July 2020, when Sony launches full-frame mirrorless camera Sony a7S III, the company also introduced new second type of CFexpress memory card — Type A. Currently, most professional cameras from all brands other than Sony choose to use CFexpress Class B memory cards. At the time of writing, CFexpress Class A cards are available in only two capacities: 80GB and 160GB.
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The most obvious feature of CFexpress Type A memory cards is that they are smaller than Type B. In fact, they measure 20mm x 28mm x 2.8mm, which is the same size as an SD memory card, even though a Class A CFe card is a little thicker. This is why when Sony produces Sony A7S III full-frame mirrorless camera, it has built-in two memory card slots that can accept SD (UHS-II) or CFexpress Type A memory cards.
However, class A memory cards have shortcomings. Importantly, they are slower than Class B cards. However, they are still faster than all current SD memory card formats.
The future of “Express” memory cards:
While there are currently only two types of CFexpress Cards – Class A and Class B – there are plans to introduce additional formats in the near future:
- CFexpress Type C: In the CFA’s 2019 press release regarding the association’s most recent CFexpress 2.0 specification update, the association noted that in addition to the Class A and Class B CFExpress cards, a third type of card, Class C, will twice the size and almost twice the thickness of a class A card: The CFExpress Type C card will measure 54mm x 74mm x 4.8mm. While like Type A and Type B, Type C will feature the NVM Express 1.3 protocol, it will also include 4 PCIe Interface lanes and have a maximum theoretical performance of 4000MB/s – four times that of a Type card A.
However, even though there is information about specifications such new memory card formats, neither the CFexpress Type C nor the SD Express memory cards have yet to be marketed. In June 2021, Lexar announced plans to produce SD Express memory cards, to be introduced next year.
CompactFlash (soon to be obsolete)
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It’s the largest type of memory card in terms of physical size, and it’s also one of the oldest, outlasting many other memory cards. You’ll find two available – CF Type II (5mm thick, can only fit Type II card slots) and Type I (3.3mm thick and can fit both types of card slots). Unlike SDXC memory cards which have a maximum capacity limit of 2TB, CF memory cards have a maximum capacity of only 512GB.
CF cards are still used by many existing cameras (including many DSLRs), but they are being phased out in new models, to be replaced by SDXC and/or CFexpress.
XQD (obsolete)
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XQD cards are still available and some current Nikon DSLRs and mirrorless cameras can accept them, but like CompactFlash, XQD has been replaced by CFexpress Type B. CFexpress Type B cards are the same size. with XQD and share the same interface, but they are much faster. As mentioned, there are a number of Nikon DSLRs and Z-series full-frame mirrorless cameras on the market that can accept both XQD and CFexpress memory cards. (Nikon lists both on the NikonUSA website) but to get the most out of your camera’s performance, we recommend using CFexpress Type B. Note that unlike Nikon, Canon cameras that accept CFexpress Type B cards will Not work with XQD media.
Since XQD and CFexpress Class B cards tend to be similarly priced, it’s not a bargain to stay with the older format.
CFast (obsolete)
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Like the XQD, the CFast card slot can still be found in some current cameras, but the format is outdated. At the time the CFast card was introduced, in 2009 and later updated to 2.0 in 2012, CFast was considered the successor to the older CompactFlash standard (and similar in appearance, if not the technology), but CFexpress Type B has emerged as a more promising standard than a format.
CFast memory cards are only compatible with select previous generation (but possibly current and still available) cameras from Canon, BlackMagic Design and ARRI. Camera manufacturers are no longer releasing new cameras that accept this type of memory card.
On the next page, we’ll explain what speed, code, and rating mean on your memory card.
