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Demystifying Camera Memory Cards: A Guide to the 8 Most Common Types

Memory cards allow digital cameras to save all those precious photos and videos that capture our memorable moments. But between the tiny microSD cards used in drones to the blazingly fast CFexpress format favored by professionals, sorting through memory card options can be daunting.

In this guide, we’ll demystify the major memory card types, compare their features and help you pick the best card for your camera. Let’s dive in!

SD Cards: The Universal Favorite

If we asked 100 photographers what memory card their camera uses, the majority would surely answer SD. Secure Digital or SD cards are by far the most popular camera memory card today. Introduced in 1999, the SD format has been widely adopted by major camera manufacturers like Canon, Nikon, Fujifilm, Panasonic, Olympus, and Sony.

Global shipments of SD cards surpassed 659 million units in 2021 according to data from the SD Association. They have become virtually synonymous with digital photography and camcorder storage.

SD card shipments by year

SD Card Shipments by Year. Source: SD Association Annual Report

SD cards slot perfectly into the SD card slot integrated into most consumer camera models. Their small size—just 24mm x 32mm x 2.1mm—gives cameras a slimmer form factor.

Here’s a breakdown of the SD card capacities and speed classes available:

  • SD (SDSC): Up to 2GB capacity
  • SDHC: 4GB to 32GB capacity
  • SDXC: 32GB up to massive 2TB storage
SD Card Speed Class Minimum Write Speed Example Use Cases
Class 2 2 MB/s Basic photo shooting
Class 4 4 MB/s 720p video recording
Class 6 6 MB/s 1080p HD video
Class 10 10 MB/s Full HD video
UHS Speed Class 1 10 MB/s 4K video
UHS Speed Class 3 30 MB/s Ultra HD 4K, burst photo

SD cards offer a winning combination of compact size, broad compatibility, good affordability, and excellent performance. For beginners and hobbyists, SD cards are the safest choice to complement consumer point-and-shoot and entry-level DSLR cameras.

CF Cards: Durable Workhorses for Professionals

While SD cards dominate the consumer market, CompactFlash or CF cards remain popular with many professional photographers. These sturdy cards were introduced way back in 1994 and have proven their reliability over decades of use.

CF cards certainly live up to the “compact” portion of their name. They measure just 43mm x 36mm x 3.3mm. But unlike the tiny SD format, CF cards are designed with thick, protective bodies that resist damage. Their larger physical size also makes them easier to grip and handle in fast-paced shooting conditions.

Durability and responsiveness are the hallmarks of CompactFlash:

  • Withstands shock, vibration, dust, moisture, and extreme temperatures from -13°F to 185°F
  • Supports blazing fast write speeds up to 506 MB/s (UDMA-8)
  • Sustained performance for RAW image bursts and high bitrate video

CF remains popular in high-end DSLR camera bodies like the Canon EOS-1D X Mark III and the Nikon D6. Wildlife, sports, fashion, and wedding photographers will appreciate the ruggedness and speed of CF cards available from 32GB up to massive 1TB capacities.

For pros who demand uncompromising performance and reliability from their equipment, CF cards deliver.

Memory Sticks: Sony’s Proprietary Pick

Sony has taken a different approach from other camera brands with its Memory Stick format. Introduced in 1998, Memory Sticks are designed exclusively for use in Sony equipment like Alpha mirrorless cameras, Cyber-shot compacts, and Handycams.

Rather than adopting the universal SD card standard, Sony wanted a proprietary card only for their cameras. The original Memory Stick stored up to 128MB, while the latest Pro versions boast capacities up to 256GB.

Memory Stick read and write speeds have improved steadily over the years:

  • Memory Stick: up to 20MB/s
  • Mark 2: up to 50MB/s
  • Pro Duo Mark 2: up to 95MB/s
  • Pro-HG Duo: up to 300MB/s

The Duo size of Memory Stick measures just 20mm x 31mm x 1.6mm for an extremely compact footprint. However, Memory Sticks do require a Duo adapter to work in standard Memory Stick slots.

For Sony devotees who stick exclusively to Alpha mirrorless or Cyber-shot models, Memory Stick provides a specialized card designed to maximize performance. But the proprietary limitation means Memory Sticks are incompatible with other camera brands.

XQD Cards: High-Speed, Low-Profile Performance

XQD cards represent one of the newest memory card formats optimized for high-end cameras. Jointly developed by Sony, SanDisk and Nikon, XQD was launched in 2010 as a successor to the CompactFlash format.

The XQD format aimed for smaller physical size but blazing fast speeds. The PCI Express interface enables theoretical transfer rates up to 1GB per second – over 8x faster than CompactFlash.

XQD 2.0 cards currently offer:

  • 440MB/s max read speed
  • 400MB/s max write speed
  • Available from 32GB to 256GB capacities

The smaller card size coupled with ultra-fast performance has made XQD popular in premium mirrorless and DSLR cameras. Nikon‘s flagship D6 DSLR model features dual XQD slots, while Fujifilm‘s GFX 100S medium format camera also utilizes XQD cards.

For professionals who need to capture ultra high-resolution images or high bitrate 4K video, XQD offers the cutting edge performance in a low-profile card design.

CFexpress: Built for 6K Video and Beyond

CFexpress takes the high-speed performance of XQD cards even further. Maintaining the same form factor as XQD, CFexpress bumps up the interface to PCIe Gen 3. This next-gen PCI Express interface propels card read/write speeds to staggering levels over 1,400MB/s.

In addition to phenomenal speed, CFexpress enables large capacities up to 1TB. The combination of high capacity and lightning fast transfer rates makes CFexpress the choice for 6K and 8K video recording along with high-resolution RAW image bursts.

Adoption of CFexpress continues ramping up with more camera manufacturers:

  • Canon EOS-1D X Mark III
  • Nikon Z6/Z7 mirrorless and D6 DSLR models
  • Sony a1 mirrorless

As video resolutions and RAW image quality move into 6K, 8K and beyond, CFexpress represents the future for memory cards. CFexpress delivers the performance tomorrow’s cameras require today.

MicroSD Cards: Tiny Storage for Action Cams and Drones

On the other end of the spectrum from CFexpress, microSD cards offer a diminutive storage solution. The microSD format is just 15mm x 11mm x 1mm in size, roughly the size of a fingernail. Introduced in 2005, microSD was designed for compact portable electronics like smartphones.

The tiny size also makes microSD cards perfect for action cams like GoPro models. For use in larger cameras, a simple SD adapter houses the microSD card.

Global demand for microSD remains strong, with around 155 million cards shipped in 2020. Consumers appreciate the affordability, wide availability, and portability of microSD for phones, drones, tablets, and cameras.

While limited to a maximum of 1TB capacity currently, microSD read and write speeds continue improving:

  • UHS-I U1 cards support at least 10 MB/s write
  • UHS-III U3 hits 30 MB/s write
  • New SD Express cards boast 985 MB/s maximum!

For consumers who need lots of storage at an affordable price point, microSD cards are a top choice. The tiny size means you can easily slip a spare card in your wallet just in case.

CFast: Lightning Speeds in a CF Form Factor

CFast cards utilize the familiar and durable CompactFlash form factor. But hidden within the CF frame lies blazing fast performance meeting professional video standards.

Introduced in 2008, CFast combines the PCIe interface and SATA-3 protocol to deliver whiplash read/write speeds. CFast 2.0 hits a remarkable 550MB/s read and 530MB/s write. This high-speed handling enables Raw 4K and 5.9K video capture along with rapid-fire image bursts.

Canon has embraced CFast storage for their advanced Cinema EOS lineup including the EOS C700 FF. This camera can record 5.9K video internally to CFast 2.0 cards. CFast gives video pros the flexibility to capture cinema-quality footage in-camera rather than requiring an external recorder.

For the highest video recording quality on a CF form factor, CFast cards represent the pinnacle. The PCIe interface future proofs the CFast standard to meet rising video resolution requirements.

SxS: Sony’s Pro Video Card Format

Sony also developed its own SxS card format designed for pro videography applications. Introduced in 2007, SxS aimed to push beyond the storage limitations of professional video recording standards at the time.

SxS and SxS PRO utilized the PCIe interface to deliver impressive performance:

  • SxS PRO – 1.3 Gbit/s theoretical max
  • SxS PRO+ – Up to 8 Gbit/s speed

The latest SxS PRO+ cards offer 700MB/s transfer speed over a PCIe Gen 2 interface. Physical durability and reliability are also hallmarks of the SxS format. Sony designed the cards to withstand shock, vibration, moisture, dust, and extreme temperatures.

While SxS adopts the newer PCIe interface, the cards remain primarily geared towards Sony’s pro video camcorder lineup like the PXW-Z750 and PXW-Z280. If you use Sony for professional videography, SxS cards integrate seamlessly. But for other camera brands, CFexpress or CFast represent more widely compatible pro card options.

Finding the Right Memory Card – Some Handy Tips

  • Check your camera manual for recommended cards to ensure full compatibility
  • Buy from reputable brands like SanDisk, Sony, Lexar, ProGrade
  • Match card speeds to your use – slower for photos, faster for video
  • UHS-II, U3 and V30/V60 signify fast write speeds
  • Avoid cheap cards from lesser-known brands
  • Select larger capacities like 64GB+ to minimize changing cards
  • Bring spare cards as backup for important shoots
  • Use card readers to transfer files instead of camera connections
  • Always safely eject the card before removal to avoid corruption

Hopefully this overview dispels any confusion over memory card formats. The key is matching the card capabilities with your specific camera and shooting style. Happy capturing!


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