When Does the Camera Use the Mechanical Shutter and When Does It Use the Electronic Shutter?

There are two primary types of shutters used in digital cameras: mechanical shutters and electronic shutters. The choice between them can depend on a variety of factors, such as the specific needs of the photographer, the environment, and the type of photography being done.

Understanding the Two Types of Shutters

1. Mechanical Shutter

The mechanical shutter is the traditional mechanism used in cameras. It physically opens and closes to allow light to reach the image sensor. This is what you would typically find in both DSLR and mirrorless cameras.

2. Electronic Shutter

The electronic shutter, on the other hand, uses the image sensor to control the exposure time without the need for moving parts. This is a faster and silent alternative to the mechanical shutter.

Which Cameras Use Both?

Both shutter types are found in modern high-end interchangeable lens cameras. For example, my Olympus OM-D cameras use the mechanical shutter as the default but offer an electronic shutter as an option. However, it's a feature that is often hidden from users to maintain a certain level of usability.

Advantages and Disadvantages of Each

Advantages of Mechanical Shutter

Provides more stable and consistent exposure

Less prone to rolling shutter effect, which can distort fast-moving objects

Usually faster and more reliable

Disadvantages of Mechanical Shutter

Makes the camera louder, which may not be ideal in certain situations

Can be more prone to wear and tear due to mechanical motion

Advantages of Electronic Shutter

Completely silent, ideal for low-light recording or situations requiring silence

Faster, capable of higher frame rates (up to 1/32000 second on my cameras)

No mechanical parts, meaning lower maintenance and longer lifespan

Disadvantages of Electronic Shutter

More prone to the rolling shutter effect, especially with fast-moving objects

Operational limitations, such as slower readout speeds and potential motion artifacts

Real-World Examples of Shutter Usage

Let's take a look at a real-world example. In the photos below, the same fan was used for comparison.

A photo of a running fan taken with the OM-D E-M1 Mark I, an older model nearly 8 years old with an electronic shutter readout speed of 1/13 s. The image shows noticeable rolling shutter distortion.

Compare this to the same fan standing still, taken with the same setting, which shows no such distortion. This highlights the impact of the rolling shutter effect in motion.

Future Trends in Digital Camerawork

Advancements in sensor technology, particularly the development of global shutters, suggest that the rolling shutter effect will become less prominent. As a result, we may see the mechanical shutter becoming less prevalent in the next 5-10 years, as electronic shutters continue to improve and offer more benefits with fewer drawbacks.

The choice between mechanical and electronic shutters ultimately depends on the specific requirements of the photographer and the photography environment. While mechanical shutters remain the standard in many professional and enthusiast cameras, the silent and high-speed capabilities of electronic shutters are becoming increasingly attractive.