For DSLR users, CompactFlash is probably the most recognizable format, although some DSLRs utilize other cards or multiple cards within the same body. CF is physically the largest, but that doesn’t necessarily mean it holds more data—though capacities now run up to a whopping 64 GB. Small camera users may never have encountered the CF format, since smaller cards are more popular for smaller cameras.
SD (Secure Digital) media cards are smaller and thinner than CompactFlash, making them ideal for camera and camcorder makers (as well as mobile-phone and other device manufacturers) who are working to shrink the form factors and weights of their devices without sacrificing storage capacity or speed. SDHC is the high-capacity version of the SD format, available in sizes up to 32 GB (for now). The SDXC format announced in 2009 may lead to future developments in SD storage well beyond the 32 GB size—perhaps someday approaching their theoretical 2-terabyte maximum.
MicroSD cards are the smallest commonly available media card on the market, about one fourth the size of an SD card. MiniSD cards are about half the size of an SD card; each is available in HC versions up to 16 GB. Because the cards are so small, they’re often used in very small cameras, phones and other electronic devices. Commonly available adapters allow the use of microSD cards in miniSD devices, as well as for both formats to fit in full-sized, SD-compatible electronics.
Olympus and Fujifilm partnered to release their own variant on the SD format in 2002, called the xD-Picture Card. This tiny format is still used in capacities up to 2 GB, although recent Olympus and Fujifilm cameras have moved toward the SD and SDHC formats.
The proprietary Sony media card format (made in partnership with SanDisk), Memory Stick is used in a variety of digital devices. From the original Memory Stick, many variations (including the PRO, Duo, Micro and XC) have arisen to address the ever-shrinking form factors and ever-changing needs of the consumer electronics industry. In Sony’s newest digital and video cameras, the PRO Duo stores up to 32 GB of data, with a theoretical maximum of 2 TB.
What’s better than a media card with a large storage capacity? How about one with unlimited capacity? Eye-Fi makes SD media cards with built-in Wi-Fi capabilities to wirelessly transfer image and video files across a wireless network. You can upload as you shoot, skipping the tethered download process altogether. The cards have a maximum capacity of 4 GB, so when you shoot out of range of a wireless network, you can still store lots of images until you’re back within range.
With so many media card options, it can be confusing to understand compatibility. Take the HC denominator, for example: Any SD card can work in any SDHC-compatible device, but the reverse isn’t true. (The same goes for mini and micro SD/SDHC formats.) Likewise, just because a CF card is marked UDMA, that doesn’t mean your camera is certain to perform better with the card inside. If you’re using the newest generation of DSLRs to record HD video or shoot large photos at high speed, chances are your camera’s manufacturer has built-in UDMA functionality to make full use of the accelerated data transfer these cards offer.
UDMA, or Ultra Direct Memory Access, represents the newest high-speed transfer protocol in CompactFlash media cards—the shared language two devices use to transfer data. UDMA represents the newest way to transfer data quickly, so cards marked with the identifier are recognizable as high performance—though not all cameras are designed to take full advantage of the cards’ efficiencies.
The ability for a media card to move data quickly is paramount for fast shooting and video recording—particularly as file sizes and video resolutions grow exponentially. Use an outdated, slow or otherwise lagging media card, and you can find yourself waiting to shoot until the card has caught up with its processing and storage duties. This data-transfer rate affects two major aspects of the photo workflow: shooting and downloading, which determine how fast the card can record images in the camera and how fast images are offloaded into the computer.
The data-transfer rate of a media card is measured in megabytes per second, or MB/s. While this number affords a good way to compare one card’s speed to that of another, these numbers also are expressed often as an “x” rating—i.e., 100x or 300x—in much the same way that recordable CD and DVD media are rated. Currently, cards 300x and faster are considered high speed, with maximum ratings of 666x representing a data-transfer rate of 100 MB/s.
Speed class is a broader term used with SD card variants to specify compatibility with various types of image-making activities. Class 2 cards, for example, work fine for basic video recording. Class 4 cards are upgraded to allow HD recording and fast shooting of stills. Class 6 cards offer the current best performance for professional video and stills at the highest available resolutions.
Some photographers choose to prioritize capacity over speed. For others, the reverse is true. Whichever features are more important to you, know that you likely can have any two of the three ideal features—high capacity, fast speed and low price—but not all three in the same media card. The best storage options for high-resolution digital stills and HD video capture, which require not only high capacities but also very fast data-transfer rates, are usually the most expensive.
Extreme Pro CompactFlash cards from SanDisk feature 90 MB/s transfer rates for fast shooting of high-res stills and HD video. In sizes up to 64 GB, the cards feature SanDisk’s Power Core Controller designed to handle the fastest camera buffers, distributing data across the CF card rapidly and efficiently. List Price: $896 (64 GB); $560 (32 GB); $336 (16 GB).
Lexar‘s Professional 600x CompactFlash cards utilize UDMA 6 technology to deliver, you guessed it, 600x performance. That means 90 MB/s is the guaranteed minimum sustained write speed on these cards—making them ideal for high resolution, high speeds and high-definition video. The cards also come with Image Rescue 4 software to help recover accidentally deleted files. List Price: TBA (32 GB); $300 (16 GB); $200 (8 GB).
PNY offers a variety of storage options for digital cameras, includin
g CF, SD, xD and MicroSD cards. The Optima Pro SDHC cards offer Class 6 transfer rates in capacities up to 16 GB, making them perfect for use in SDHC-compatible DSLRs, as well as advanced point-and-shoots and video cameras. For more capacity at a slightly lower speed, check out the Optima SDHC—a Class 4 card up to 32 GB in size. List Price: $60 (16 GB); $150 (32 GB).
For photographers with a penchant for ever-smaller cameras and media devices, Kingston‘s Micro SDHC card may be the perfect accessory. This tiny card still carries a whopping 16 GB capacity, making it a great choice for the growing world of high-resolution and video-enabled compact cameras and multimedia storage. Kingston also offers a full range of card options for every camera. List Price: $90.
Sony shooters working with everything from compact Cyber-shots to DSLR Alphas and even Handycam video camcorders rely on Memory Sticks for a total media storage solution. Thanks to the new Memory Stick PRO Duo, they now can store up to 32 gigs of data and transfer it on and off the card at 32 MB/s. Estimated Street Price: $175.
Looking for the CompactFlash card that boasts zero failures brand-wide for more than two years? You’re looking for the RAW line of UDMA CF cards from Hoodman. With SSD flash media inside, the 675x (90 MB/s) cards are designed for maximized stability and reliability through half a million fill/format cycles. List Price: $300 (16 GB); $180 (8 GB); $90 (4 GB).