Camcorder Frame Rates

In reviewing camcorder specifications, you’ll frequently see the term "frame rate." It’s expressed as the number of frames captured per second (fps, for frames per second).

A frame is basically a still photograph. Take enough of them in quick succession, and you have full-motion video. Frame rate, then, refers to how many frames a camcorder will capture in a single second, which determines how smooth a video will look.

Choosing a Frame Rate

Typically, camcorders record at 30 fps to give the appearance of seamless movement. Motion pictures are recorded at 24 fps, and some camcorder models offer a 24p mode to mimic feature films. Recording at a slower frame rate than 24 fps results in video that looks jerky and disjointed.

Many camcorders offer the ability to shoot at faster frame rates than 30 fps, usually 60 fps. This is useful for capturing sports or anything involving fast movement.

Slow-Motion Recording

If you speed up the frame rate to, say, 120 fps or higher, you can record video in slow motion. That may sound counterintuitive at first: Why would a faster frame rate give you slower motion?

At a higher frame rate, you’re capturing even more details of movement in each passing second. At 120 fps, you have four times the amount of video information than you do at 30 fps.

It's the higher number of still shots that allows the camcorder to slow down the playback of the video and deliver slow-motion footage in your video editor.

Shutter Speed

If you've heard of the term "frame rate," you've maybe also heard about shutter speed. These two concepts are related but are not the same.

Frame rate refers to the number of images that are captured every second — and therefore, the smoothness of the video. The shutter speed, on the other hand, refers to how long the camera shutter is open while taking a picture; this translates to the amount of light that the image sensor can use to record the picture.

When the frame rate is very low, the video might look choppy because not enough images were taken. If the shutter isn't open long enough (i.e., the shutter speed is too short), the image won't get enough light and will be underexposed.

It's common for the shutter speed to be double the fps for recording. For example, if your camcorder is set to record at 30 fps, the shutter speed should be 1/60th of a second. This means that every frame (30 for every second) is being exposed for 1/60th of a second.