Mechanical vs Electronic Shutter vs EFCS

Many cameras today, especially mirrorless cameras, let you pick between a mechanical and electronic shutter. Others – including a lot of DSLRs – have a third option called “electronic front curtain shutter” (EFCS) which is a blend between the other two types. Each shutter mechanism has several pros and cons, more than you might have realized. If you pick the wrong one, you could be harming your image quality.

What Is a Mechanical Shutter?

Today, mechanical shutters are the default shutter mechanisms for still photography. Many older cameras and even some new ones only allow you to take pictures with a mechanical shutter.

Mechanical shutters function using physical “shutter curtains”: two blades with a gap in between. When you take a photo, the blades slide rapidly in front of your camera sensor. Any light that hits the sensor between the blades will appear in your image.

You do not need to do anything special to enable the mechanical shutter on your camera. It is almost certainly enabled by default.

What Is an Electronic Shutter?

Electronic shutters are becoming more and more popular nowadays, but they still are not present in many modern cameras.

In general, electronic shutters work by reading data from your camera sensor line-by-line. A few cinema cameras have something called a “global shutter,” which reads the whole sensor simultaneously rather than line-by-line, but, at least for now, this technology has not found its way to consumer DSLRs and mirrorless cameras.

To enable the electronic shutter, you will need to enter your camera menu. On some cameras, like the Sony A9, it is obvious how to change to the electronic shutter: Camera Settings 2 > Shutter Type > [Electronic Shut.]. However, other cameras hide this option under a “silent shooting” mode. For example, on the Nikon Z6, the only way to enable the electronic shutter is: Photo Shooting Menu > Silent Photography > On.

Again, not all cameras have an electronic shutter option, especially DSLRs.

What Is Electronic Front Curtain Shutter?

Lastly, electronic front curtain shutters are a blend between standard mechanical and electronic shutters. In this case, the first of the two “shutter curtains” is electronic, while the second is the traditional mechanical blade.

Enabling EFCS is easy on most cameras. For example, with the Sony A7 III, you simply go to: Shooting Menu 2 > e-Front Curtain Shut. > On. With the Nikon D810 and D850, go to: Custom Setting Menu > Shooting/display > Electronic front-curtain shutter > ON.

However, on certain cameras – specifically the Nikon D810 and D850 – turning on EFCS sometimes does not do anything. In order for it to work at all on the D810, you need to be in Mirror Up release mode; on the D850, you need to be in Mirror Up, Quiet, or Quiet Continuous release mode. Luckily, most cameras do not have this issue.

We talk about these limitations and more in our article on shutter shock.

Non-Image Quality Differences

Before diving into the factors that impact image quality, let’s take a look at some of the more general pros and cons of these three shutter types.

Fastest Shutter Speed

Which shutter mechanism lets you shoot at the fastest shutter speeds today? In general: Electronic, followed by Mechanical, followed by EFCS.

Electronic shutters on some cameras, such as the Sony A9, let you shoot at extreme shutter speeds like 1/32,000 second. However, not all cameras with electronic shutters will max out so high.

Mechanical shutters generally max out at 1/4000 or 1/8000 second depending on the camera. This is still quite fast – enough for typical needs.

Electronic front curtain shutters are usually the slowest of the group, often maxing out around 1/2000 second. Even on cameras that allow faster EFCS shooting, the manufacturer will often recommend against it due to potential uneven exposures. Although 1/2000 second is fast, it won’t always be enough in bright conditions.

Maximum Frame Rate

Another important point is that different types of shutter may have different maximum frame rates. If this applies to your camera, it’s usually the electronic shutter that can support the greatest number of frames per second. For example, the Nikon V3 can shoot 6 FPS with its mechanical shutter, and a whopping 20 FPS with electronic shutter. Your camera manual will say if yours is the same way.

Flash Use

Mechanical shutters are generally ideal for use with a flash. On many cameras, you can’t even use the electronic shutter in combination with a flash at all. On the few cameras that do allow it (such as the Nikon 1 V3), it will max out at a slow sync speed (1/60 second in this case).

Flash with electronic front curtain shutter is better; most cameras let you use it without any different restrictions. However, with high-speed sync and external flashes, you’ll often see very visible banding in your images around 1/1000 second. So, with flash, I would stick to the mechanical shutter.

Silent Shooting

For situations when you need the quietest possible camera, you’ll want to go with the electronic shutter. This is no surprise, since it has the fewest moving parts. It’s followed by EFCS, then mechanical shutter in terms of volume. However, note that even the electronic shutter may not give you totally silent shooting, since other components of the camera (especially aperture and focusing) also make sounds as you take photos.

Other Differences

There are some more minor differences between the three shutter mechanisms, too:

  • You will wear out your camera’s shutter curtains more quickly if you exclusively use the mechanical shutter.
  • There are differences in response time with each type of shutter (the time between pressing the shutter button and when the camera starts taking the photo). In general, mechanical shutters have a slightly slower response time, although this is not true on every camera.
  • At fast shutter speeds (1/2000 and beyond), electronic front-curtain shutter can result in uneven exposures.
  • Electronic shutter can prevent you from using certain menu items on some cameras. For example, on the Sony A9, you cannot use long exposure noise reduction or Bulb mode with the electronic shutter. On the Nikon Z cameras, you cannot use long exposure noise reduction.
  • On mirrorless cameras, the electronic shutter can eliminate viewfinder blackout (and live view blackout) from shot to shot. This can be useful for continuous shooting, making sure you never lose sight of the scene in front of you.

Next up, let’s take a look at image quality differences for each type of shutter.

Sunstar Flare

In certain cases (especially at fast shutter speeds), using the mechanical shutter can introduce a peculiar type of flare to bright objects in a scene. It is not really flare in the traditional sense, but instead a special kind of sunstar. If you have not heard the term “sunstar” before, it refers to the sharp edges of light seen in certain photos, like the one below:

Normally, sunstars are caused by aperture blades in your lens. But the shutter curtain can cause them as well, and things don’t look good when it does. I call this “sunstar flare” for lack of a better term:

Again, it’s the biggest problem at extremely fast shutter speeds. The image above is so extreme in large part because I’m shooting at 1/5000 second. However, until about 1/125 second (at least on my Nikon Z7), the effects can still be strong enough to be annoying. So, how can you minimize them?

Take a look at the following images, all captured at 1/2000 second and uncropped. Once again, the order is mechanical shutter, EFCS, electronic shutter:

That’s a pretty striking difference! The mechanical shutter has two distinct “sunstar flares,” while the EFCS has one (representing the exposure’s mechanical rear curtain). The electronic shutter does not have this issue at all.

Ranking:

  1. Electronic shutter
  2. EFCS
  3. Mechanical shutter

Flickering in Artificial Light

One of the other major effects of your shutter mechanism involves flickering/banding issues in artificial light. It’s most obvious in the following set of images. The order is still mechanical, EFCS, electronic shutter. Click to see full size:

As you can see, in this example, the only image to have noticeable banding issues is the third – taken with the electronic shutter. In general, that’s what you’ll see; mechanical and EFCS are not a problem in terms of banding. However, some specific cases with EFCS and artificial light can result in banding issues as well, especially when you are using fast shutter speeds like 1/2000 second. For example, take a look at the comparison below. Mechanical shutter is Before, EFCS is After. This is a moderate crop, roughly 1/5 the original area:

Previous ArticleNext Article