When we go to buy a new memory card for our cameras, we are bombarded with cards advertising their amazingly fast read/write speeds. But why is speed so important? Are the super-expensive, super-fast cards worth the extra money? And what risks are you taking if you buy a “slow” card?
Let’s start with the most important factor first. What risk are you taking if you buy a slow card? Simply put, a slow card may be the difference between getting the shot or not. One of the worst feelings a photographer can have is being in the right place to get a great photo, but not being able to get the picture!
Nearly every DSLR camera today can shoot frames faster than it can write them to a memory card. Therefore, a slow card will increase your chances that your camera’s internal memory buffer will completely fill up as it is trying to write the photos to the card, which means your camera stops taking photos until the buffer clears enough to take some more.
This likely will never happen if you are doing something like portraiture and landscape shots, but if you are shooting a live news event where you need to shoot in rapid fire mode, such as sports, lively protests or a fire scene, it can certainly happen.
Don’t just rush out and buy the fastest cards you can find however. How fast your images are written depends not only on the speed of the card, but also how fast your camera can write to a card and how well it interacts with the card itself. Putting a super fast memory card into a slow camera would be like dropping a racing transmission into a Ford Escort. The Escort isn’t going to drive any faster and you’re wasting your money.
So what should you do? Luckily for us, there is a great resource on the Web that has tested dozens of memory cards produced by the top-selling companies. The CF/SD Performance Database can be found here.
Find your camera in the drop down menu at the top to get specific information. If your camera isn’t listed, check out the archives for models no longer being updated.
Here’s the bottom line. You can’t go wrong buying the fastest cards available, but unless you have one of the newest cameras on the market, you won’t be utilizing all of that speed. If your camera is a few years old and you want to save some money, the difference between the fastest cards on the market isn’t significantly better than some of the slightly slower cards.