Understanding Your Camera : Frame Buffer
Imagine owning a camera that only allowed you to take one shot and then forced you to wait for a second or so before you could take another. That, I think you’d agree would be slightly restrictive. The fact that digital cameras have continuous drive modes at all is down to something known as a frame buffer.
When you expose an image in a digital camera the data from the sensor needs to be saved to a memory card (or to a hard drive when the camera is tethered to a PC). This can be a slow process. To avoid a bottleneck the image data is temporarily stored in an area of memory inside the camera: the frame buffer. The practical upshot of this is that you can shoot continuously without everything coming to an immediate and embarrassing halt.
Now, not every camera is equal and some have bigger frame buffers than others. The larger a camera’s frame buffer the more data can be temporarily stored until it is all safely written to the memory card. Some cameras need to have big frame buffers. The higher the resolution of the sensor, the bigger the frame buffer needs to be. More resolution means more image data and a greater potential for a bottleneck.
The size of a camera’s frame buffer is one factor that affects the camera’s maximum achievable burst rate. The burst rate is the number of shots a camera can continuously shoot before it needs to pause and gather breath. This not to be confused with the frame rate, which is the maximum number of images a camera can shoot per second.
The type of file you’re shooting also affects the maximum achievable burst rate. Raw files tend to be larger in file size than Jpegs. Typically a camera will be able to shoot fewer Raw files continuously than Jpeg. Shoot Raw plus Jpeg and the burst rate will be lower still. Finally, the speed of the memory card you use will have a bearing on the burst rate. The slower a memory card the longer it will take the frame buffer to clear and therefore the greater the chance that your camera will temporarily stop shooting.
For some types of photography the frame buffer and the burst rate of a camera are largely irrelevant. Landscape and portrait photography rarely need to shoot continuously. If your camera stops shooting it’s more likely to be because it’s raining and your camera’s wet. That said, shoot in Bulb mode and you may find that you can’t shoot another image until the first has been processed. Cameras vary in whether you can shoot ‘continuously’ in Bulb mode when long exposure noise reduction is enabled. Personally, I tend to switch this off and deal with noise in postproduction.
It’s action shooters who are more likely to push the limits of a camera’s frame buffer and burst mode. For this reason it’s a sensible policy to use the very fastest memory card possible and consider shooting in Jpeg only. This also has the advantage that more images can be fitted onto the memory card. So there’ll be less chance of missing something because the card is full.
The details of a camera’s burst rate are usually found in the specifications at the back of the manual. Why not take a look today. If you’re feeling particularly adventurous you could even try to fill your camera’s frame buffer. It’s always worthwhile experimenting like this to understand and appreciate your camera’s capabilities. You never know when that knowledge will come in useful…
I have two cameras (well actually I have more cameras than that but most of them are old and un-repairable and have been turned into unusual and decorative paperweights). One camera can be slipped into a coat pocket and makes an ideal companion for a […]
Sesquipedalian is a word that isn’t used as often as it should. It describes someone prone to using long words. Which I think is just wonderful. A word to describe someone prone to using long words is itself a long word. When you first take […]
Variety, it is said, is the spice of life. And it’s true. Can you remember every last detail of your regular journey to and from work this past week? I suspect you can’t. Unless of course something extraordinary happened. Such as being kidnapped by a […]
After many years as a keen amateur photographer, I decided to start a small landscape photography business called Lakescenes which I ran alongside my main job as an IT Manager. As business increased, I found myself working long, but rewarding, hours just to keep up […]
Rob Sheppard is a naturalist, nature photographer and videographer who says his favorite location is the one he is in at any time. He is the author/photographer of over 40 books, as well as a well-known speaker and workshop leader, and a Fellow with the […]
Gary Hart has photographed California’s natural beauty for over 30 years. Gary’s photos and writing have appeared in many publications, most recently Outdoor Photographer and Sierra Heritage magazines. You’ll also find his images in greeting cards, postcards, calendars, and many galleries and private collections throughout the world.
Originally from Poland, based in London UK, Jaroslav has background in Fine Arts, degree in Architecture, and wide array of experience. Being an Architect taught him how to be resourceful and to solve complex problems with simple, yet innovative solutions. Constant passion for graphic & […]
I love the texture of old heritage photos, particularly those that have been kicking around for some years and which have managed to accumulate folds and crinkles. While it can take many years for a printed photo to develop this sort of quality, luckily Photoshop […]
Five of the world’s top Olympic sports photographers talk about what it’s like to shoot the biggest sporting event in the world. Getty Images photographer Streeter Lecka puts it best: “The Olympics are unlike anything you will ever shoot in sports,” he says. “For professional […]
Camera makers are trying everything to revive the tanking market of low-end shooters. Their latest gambit? Insanely long zooming cameras that reach across vast swaths of land. But zoom is just another sweet-sounding spec that could leave you with crappier pictures. Way back in the […]