Many cameras today have two types of shutters, a mechanical shutter and an electronic shutter. You might be thinking this only applies to mirrorless cameras, but some DSLR cameras also have both. I love the ability to use an electronic shutter on my D850. I can shoot in a silent mode and use my LCD in Live View to ‘touch, focus and shoot’. Mirrorless cameras like the Z7 and Z6 also have both types. But why use one over the other?
First, just a simple description how both work, since this directly relates to how each performs. Mechanical shutters have two blades; the front curtain opens at the beginning of the exposure, and the rear curtain closes at the end of the exposure. At very fast shutter speeds, both front and rear curtains are moving at the same time only exposing a small slice of the sensor during exposure. Electronic shutters work by turning on the sensor to record light; there is no mirror that flips up during exposure as in DSLRs. Electronic shutters exposure the sensor row by row down the sensor. No matter what the shutter speed, this process takes about 1/15th of a second.
Which to use, and what are the advantages/disadvantages of both?
Silent shooting: Electronic shutter is the way to go there. There are no moving parts (like a mirror flipping up), so it is truly silent. Wedding photographers love this mode, no distractions during tender moments. Also handy for any event where shutter noise is a distraction.
Flash photography: Mechanical shutters are the way to go. In fact, most mirrorless cameras will disable flash with the electronic shutter turned on. So if you are wedding photographer as in the scenario above, you have to turn on the mechanical shutter to use flash during the ceremony.
Vibration reduction: The choice here would seem to be the electronic shutter, but actually there is some ‘shutter shock’ at slow shutter speeds. Some mirrorless cameras offer electronic front curtain shutter, which is the best choice to minimize vibration. With a mechanical shutter, best to use mirror lockup or shutter delay.
High speed subjects: Even though electronic shutters can shoot at very high speeds, it is best to use the mechanical shutter to minimize the ‘rolling’ effect of electronic shutters. Try photographing a fast moving car or a ceiling fan turned on high. Notice how the angle and shape is bent and skewed? This is due to the sensor vertical row by row capture of the electronic shutter. On the same note, trying panning a video segment really fast right to left. You will see bent angled subjects due to rolling shutter.
Wear and tear on the camera: Use your electronic shutter to avoid more wear on your camera. Mechanical shutters are often rated for actuations, such as 1/250,000 or more. Electronic shutters don’t have this issue, and reduce the actuations on your mechanical shutter.
Indoor lighting: Many indoor lights such as fluorescent like actually flicker when they are emitting light. To avoid seeing banding in your image, it is best to use the mechanical shutter. With electronic shutters one row of pixels may record the light on while the next row of pixels records the light off as the lights cycle. Also try slower shutter speeds to avoid banding under indoor lighting.
Fastest frame rate: This goes to the electronic shutter since the mirror doesn’t have to move out of the way during exposure. Mirrorless cameras with electronic shutters can shoot at 20FPS and higher.
There you have, a quick guide to when to use what shutter. For most of my shooting I use the mechanical shutter. I don’t want to have worry about rolling shutter effects with fast moving subjects, and I use flash a lot. But occasionally the silence of the electronic shutter is very convenient during sensitive shooting scenarios. Your choices will depend on your style of photography.