How to buy a camera: how fast should your new DSLR be?
For action photography and sports photography enthusiasts, when you’re trying to capture the critical moment it’s handy being able to fire off a rapid burst of shots. But high frame rates are equally useful in portraiture, enabling you to capture fleeting expressions when speed is often of the essence
Switch to continuous drive mode and your camera will keep taking photos for as long as you keep your finger on the shutter button. Buffer memory constraints aside (see below), continuous drive rates vary from about 3fps (frames per second) on the Canon EOS 1100D and Nikon D3100, to a staggering 12fps (or 14fps if shooting JPEGs) on Canon’s current flagship camera, the EOS-1D X.
Other cameras come close; the mid-range Canon EOS 7D manages an impressive 8fps, while the Nikon D300S shoots at 7fps, which increases to 8fps if you fit the optional MB-D10 battery grip with an EN-EL4a battery, or fill it with AA batteries.
Other cameras may enable you to boost the continuous drive rate by disabling autofocus tracking and metering corrections during the sequence, but this can sometimes be a bit limiting.
To make the most of high drive speeds, cameras also need to be big on processing power, so they can handle all the images in quick succession. The latest cameras’ image-processing chips are generally much more powerful than in older models. Some cameras, such as the high-speed Canon EOS 7D, actually feature two image processors for an even greater performance boost.
Shoot in medium to high resolution JPEG mode and you can often maintain the maximum burst rate of your camera’s continuous drive mode almost indefinitely. Switch to raw image quality and it’s likely you’ll clog up the camera’s internal memory buffer after just a few seconds.
You’ll then have to play the waiting game, while the buffer memory is written to the memory card – depending on the speed of the memory cards you use, this can take quite a while, slowing your potential maximum frame rate to a crawl.