Electronic shutters and mechanical shutters, so what really is the difference?
The majority of us know what a shutter is in relation to our cameras. It's the mechanism by which we expose the sensor to light for a predetermined period of time. Traditional DSLR cameras use a mechanical shutter, while the majority of mirrorless cameras have an electronic shutter.
However, what you might not know is that some cameras these days have two variants of the shutter, a traditional mechanical shutter and an electronic shutter. The Fuji X-T series is an example of that. So what are the differences and pro and cons of these two different types of shutter?
First Up, The Mechanical Shutter
Mechanical shutters use a rolling curtain that crosses the sensor at a fixed pace. There is a front curtain and a rear curtain and a gap between the two. The gap between the two determines our shutter speed, the larger the gap, the longer the shutter speed.
On DLSR cameras the shutter also has to synchronise with the mirror. The mirror is what reflects the light from the lens into the camera’s viewfinder. As the shutter button is pressed the mirror rapidly flips out of the way just before the shutter curtains begin their travel across the sensor plane.
In older film cameras the shutter travelled horizontally across the film plane but in more recent cameras the shutter moves through the vertical plane. This allows for much shorter shutter speeds due to the shorter travel the curtain needs to make.
As you might imagine, for a camera to do this in 1/1000th of a second or less involves some very sophisticated engineering and electronics. As with all electro-mechanical components, this can fail. For this reason camera companies specify an actuation figure for their shutters. This is the number of shutter operations the camera can make before the shutter may fail. Let’s look at the pros and cons of the mechanical shutter.
Pros Of Mechanical Shutter:
- Higher Flash Synchronisation – Most mechanical shutters will allow flash to operate at higher speeds than electronic shutters
- Rolling Shutter Reduction – Rolling shutter manifests itself as a lateral distortion in images, particularly where the camera is panned fast. This can also reduce the jello effect when shooting video.
- They work much better in with flickering light sources such as fluorescent.
Cons Of Mechanical Shutter:
- Lower Top Shutter Speed – Due to the mechanical nature of these shutters, the maximum speed is often significantly less than an electronic shutter.
- Limited Life Span – The moving parts of a mechanical shutter are prone to wear and tear and have the potential to fail.
- Shutter Shock/mirror Slap – These two issues can cause slight camera shake in images if not controlled.
- Response Time – mechanical shutters in some cameras have slightly slower response time due to the delay in time between pressing the shutter release button and when the camera takes the photo.
Mechanical shutters are best for portrait, wedding, events photography as you may use a flash when needed. When there artificial light in the scene, again use mechanical shutter to avoid rolling shutter issues. Sports, cityscape, night photography will do best with mechanical shutters as you may have to shoot in situations where you are dealing with artificial light.
The Electronic Shutter
If you own a mirrorless camera you will have probably noticed that with the lens off, you can see straight through to the sensor. The way the electronic shutter works is to simply switch the sensor on and off again. However, most cameras use a rolling electronic shutter where the sensor is switched on and off, row by row.
The lack of any mechanical features makes them completely silent, however, there are a number of issues with electronic shutters. Let's look at the pros and cons.
Pros Of Electronic Shutter:
- Totally silent, ideal for wildlife photographers and other genres where the photographer needs to be quiet.
- Capable of much higher top shutter speeds than traditional mechanical shutters. 1/32000th of a second is not unusual
- Capable of much higher continuous shooting rates as the camera does not have to wait for the shutter to close and mirror to return.
- Electronic shutters in mirrorless cameras can eliminate viewfinder blackout making it a great advantage during continuous shooting.
- Can reduce vibrations thereby avoiding blurry photos at specific shutter speeds.
Cons Of Electronic Shutter:
- Due to the line by line pixel scanning of an electronic shutter, rolling shutter can be much more pronounced, particularly in fast-moving subjects.
- Electronic shutters do not deal well with flickering light sources. Often banding can be seen around such lights and is difficult to remove.
- Flash sync speeds are often much lower with electronic shutters.
- Electronic shutter may sometimes prevent you from using certain menu items or features in certain cameras.
Unless there is artificial light or any other moving objects, when shooting landscapes you can use electronic shutter. Street and documentary photography can do with electronic shutter as you can shoot quietly. However if there is artificial light in the scene, then switch to mechanical shutter.
Which One Should I Use?
Not all cameras will offer both an electronic and mechanical shutter however there are increasing numbers that do.
Unless you subject your cameras to huge numbers of shutter actuations or have a need for absolute silent operation, then the mechanical option is most likely to be the better option.
There are some cameras that now allow you to have a combined hybrid electronic and mechanical shutter. This gives you the pros of both but also some of the cons of both. For the average everyday user, the mechanical shutter, if available, is going to be the best option.
Let us know in the comments below which type of shutter you prefer.