Today’s Question: I’m starting to try my hand a making videos in addition to still photos. I’ve discovered that the shutter speed can’t be set slower than 1/30th of a second. Why is that? And what shutter speed should I use?
Tim’s Quick Answer: The shutter speed for video is limited based on the frame rate for the video. So, at 30 frames per second, for example, the slowest shutter speed available would be 1/30th of a second. In general I prefer to use a shutter speed at or near this limit to maintain a persistence of motion effect.
More Detail: When recording a video at 30 frames per second (fps), each frame essentially represents 1/30th of a second. Therefore, the slowest shutter speed you could use at 30 fps is 1/30th of a second. For video captured at 60 fps, the slowest shutter speed available would be 1/60th of a second.
In some cases you may want to use a fast shutter speed for video, if it is important to freeze the motion of a moving subject. However, that can lead to a somewhat “stuttering” appearance in the video, which can be distracting to the viewer. Instead, you generally want to maintain a “persistence of motion” effect, where a slight motion blur makes movement in the frame appear more natural.
The general rule in video capture is to use a shutter speed with half the duration based on the frame rate. So, for example, you could use a 1/60th of a second shutter speed for video shot at 30 fps, and a 1/120th of a second shutter speed for video captured at 60 fps.
Personally, I tend to prefer the look with a slightly slower shutter speed for video, so I often shoot with the slowest shutter speed possible for video at normal frame rates. If I want to somewhat freeze the motion, such as when there is a particularly fast-moving subject you’ll be recording, you may want to use a slightly faster shutter speed. But in general, very fast shutter speeds for video at normal frame rates will produce a result that is not as pleasing compared to the use of slower shutter speeds.