How to Choose a Digital Camera Memory Card

In 1997, I demonstrated the Minolta DiMAGE V digital camera to Microsoft’s Bill Gates during a closed-door meeting at the Photo Marketing Association trade show. As I recall the event, Mr. Gates wasn’t overly impressed by the $649 VGA-class digital camera, despite its detachable zoom lens. He did hum in amazement, however, while examining the camera’s wafer-thin SSFDC memory card (better known as SmartMedia). “Two megabytes,” he said, and shook his head in a gesture that I took to indicate surprise.

Eight years have passed, digital SLR camera bodies are selling at prices lower than Minolta’s original 0.3-megapixel model, and memory cards of 2 GB and larger are common. A 2 GB digital camera memory card has 1,000 times greater capacity than that SSFDC had. Now, that’s progress!

SmartMedia is still with us today, but new cameras aren’t being designed around the format. Camera makers have followed two separate approaches to the adoption of one type of storage media over another: standardized or proprietary. Companies like Fujifilm, Olympus and Sony follow the proprietary route and produce cameras that use their own type of memory card (although there are exceptions); the other manufacturers have stuck with the standard formats. Each philosophy has its advantages and disadvantages, and each format has its advocates as well as its detractors. All told, four types of memory cards dominate the field for digital camera usage.

Memory Card Types
SecureDigital (SD) is the most popular format. Its small size makes it the card of choice for camera designers and has enabled the development of super-compact models. For most camera applications, it’s fully interchangeable with Multi-MediaCards (MMC), but because MMC doesn’t have exactly the same electronic interface, it can’t be used in certain other handheld devices. If you plan to swap data between a camera and, say, a Palm Pilot, you have to use genuine SD.

CompactFlash (CF) is a favorite in cameras that produce large image files. Available in two physical variations, Type I is 3.3mm thick and usually will function in devices that call for Type II, which is 5mm thick and rarely is seen in consumer-level cameras. Simple, isn’t it? Microdrives are the same size as Type II CF cards, but record images on spinning media instead of flash memory. Because they’re, in fact, miniature hard drives, they require reasonable protection from impact. On the bright side, they often offer higher capacity at a lower price than their solid-state cousins. It’s also possible to use SD cards in CF Type I slots by means of an adapter, so if your D-SLR uses CF, you do have options.

Cameras that use Memory Stick, and the derivatives Memory Stick Pro and Memory Stick Pro Duo, are virtually exclusive to Sony. Shaped like a baby stick of gum, Memory Sticks are a little bit larger than SD cards and, therefore, a bit harder to misplace. In the past, they suffered a bad rap because their maximum capacity lagged behind other formats, but the two largest manufacturers, SanDisk and Sony, appear to have resolved that issue.

The xD-Picture Card is the smallest popular memory card and easily can hide beneath a first-class postage stamp. Newer Fujifilm and Olympus cameras use this card (if you own an older model from these two brands, you may require a SmartMedia card). While the development road map for this format promises higher and higher capacities, they’ve yet to be realized.

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Comparison Shopping
In addition to their form factor, or physical configuration, memory cards are categorized by their capacity and operating speed. The benefit of a large-capacity card is obvious: it holds more images than a smaller card. The benefit of a high-speed card is that, under the right conditions, you can record and play back large image files faster. There are other limiting factors, however. Each individual camera will work with a memory card based upon the camera’s internal components and firmware, so be aware that the figures you see touted by memory card manufacturers might not be the same for your camera. Still, the specs give you a good idea for the relative performance of one card versus another.

 

Popular synonyms for capacity are “size” and “density,” but no matter how you say it, it’s a measurement of the space where image files are stored and is expressed using the same increments used for computer DRAM memory—megabytes and gigabytes. Measurement of operating speed is a bit less comprehensible, however. The two speed-related specifications that determine how fast the data is handled are the sustained sequential write speed and sustained sequential read speed.

Upgrade
The memory card that came with your camera is too small. In fact, some camera makers don’t supply any card at all, even with consumer-level products. Any accessory that the manufacturer puts in the box with the camera cuts directly into their bottom-line profit, so it’s natural for them to be penny-pinching. Plus, the retailer wants the opportunity to sell you a bigger card when you buy your camera. What capacity card should you buy? It all depends on your camera, your shooting habits and your wallet. If you shoot with a digital SLR, you’ll want more than one card, of course, and probably higher capacity as well—which brings up an interesting question.

Is it better to have one 4 GB card or two 2 GB cards? We asked John Omvik, director of professional product marketing for Lexar Media. “There are two schools of thought,” he says. “Some people prefer large-capacity cards so they don’t have to stop shooting to change media. Others like to use smaller cards because they feel like they’re not putting all of their eggs in the same basket.”

Memory cards require reasonable care, but they’re tougher than you may think. It’s not a good idea to carry a handful of them loose in your pocket—keep them in a case and be careful not to expose the electrical contacts to any foreign substances. Beyond that, they don’t require special treatment. There have been various reports about memory cards surviving all sorts of extreme tortures. Those stories are entertaining, but shouldn’t encourage you to abuse the media.

Despite their durability, memory cards face one major hazard: being lost. Buy a card case. Even if you don’t need to worry too much about the data being corrupted, it’s just plain common sense to keep the cards in a case so they’re easier to find. Hakuba, Lowepro and Tamrac make some very functional cases, just to name a few. Also, when you go to the local camera shop to have digital prints made, copy your image files to a CD and leave the memory card at home. If the CD gets lost, you’re out a quarter. If you lose the memory card, you could be out $50 or more.

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Write, And Write Again
The core benefit of any memory card resides in the fact that it can be reused over and over simply by deleting unwanted images. That also means images can be deleted accidentally. Because deleted images aren’t actually “erased” until a new image is saved in the same space, it’s reasonably easy to reverse the accidental deletions and avert disaster. First and foremost, however, it’s critical that you don’t save any additional images to a card after the accident occurs, otherwise you’ll overwrite the images you want to reclaim.

 

Lexar Media offers Image Rescue 2.0, a simple menu-driven undelete software package that works like a charm. It also includes utilities that allow you to update memory card firmware, run diagnostic tests and perform other functions. SanDisk has a similar product, Rescue PRO 1.0. There are other brands available, but you won’t find anything better than these two. The fact that deleted images can be restored should give you pause. If you loan your digital camera to a friend, it may be possible for them to see what you’ve been shooting, even if you reformatted the card. Applications like Lexar’s Secure Erase, included with Image Rescue 2.0, prevent this by overwriting every byte with a 1 or zero.

Future Trends
Some camera makers are starting to build more memory into the camera instead of packing a memory card in the box, a great change, as the bundled card is invariably too small anyway. Additional on-board memory always will be useful. Some research has shown that a certain segment of consumers buy one large memory card, install it in their camera and never think about media again. A point-and-shoot camera that has 1 GB of storage built in would seem ideal—if the marketplace and retail world would accept it.

Building a USB interface right on the memory card is another innovation that will become mainstream in the near future. The SanDisk SD Plus can be used in any SD application, but can be plugged directly into a USB slot simply by folding the innovative design in half. Think of it as a combination memory card/thumb drive.

Two specifications that will continue to grow and improve are capacity and read/write speeds. Progress in these areas is fueled by the expanding popularity of digital SLR cameras, ever-growing image file sizes and by the fact that, in the final analysis, there aren’t many other specs that can be improved. Manufacturers try to differentiate their products by using distinctive colors, attractive packaging and other superficial gimmicks, but consumers demand performance, and they spell it “big and fast.”