Digital cameras have shutters, too. They can have either a mechanical shutter, which opens and closes to expose the sensor, or an electronic shutter, which simulates the same process. Many digital camera have both types of shutter, relying on a mechanical shutter for relatively longer exposures (usually 1/500th second to more than a second long), plus an electronic shutter for higher shutter speeds that are difficult to attain with mechanical shutters alone. (That’s why you’ll find digital cameras with shutter speeds as high as 1/16,000th second: they’re electronic.) Mechanical shutters can work with any kind of sensor. Some special flash systems can synchronize with electronic shutters at higher speeds.

The type of electronic shutter your camera has depends a great deal on the kind of sensor that is built into your camera. Both terms deal with how the sensor captures an image. The interline sensor, developed originally for video cameras, isolates an entire image in one instant, and then gradually shifts it off the chip into the camera electronics for processing and conversion from an analog signal to digital format. The two sensors exchange places so that the previously masked sensor can then accept light while the sensor that was previously exposed is shielded so it can offload its image to the camera’s electronics. A full-frame sensor (not to be confused with full-frame sensor size), in contrast, is a single sensor that cannot isolate an image while it is still exposed to light. to the camera’s electronics. If the sensor is still exposed to light when an image is moved from the chip, the image will be smeared by illumination that strikes the photosites while the old image is being shifted. That calls for a mechanical shutter.