One of the components we have on our camera to control exposure is the shutter. Before there was such a thing as mirrorless cameras, our camera only had a mechanical shutter. In this modern age of digital photography our camera can have a physical, mechanical shutter and an electronic shutter. Some of the newer mirrorless cameras may ONLY have an electronic shutter. So, what’s the difference, and are there any advantages or disadvantages to using one over the other? Here we’ll discuss the electronic shutter vs. the mechanical shutter.
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What Does the Shutter Do?
Before we dig into the differences between the electronic shutter vs. the mechanical shutter it’s a good idea to understand what exactly the shutter is. The shutter determines the amount of time the camera’s sensor is exposed to light. A faster shutter speed allows less light to hit the sensor because it is exposed to light for less time than a slower shutter speed.
Shutter speeds are measured in fractions of seconds and whole seconds. For example, if we set our shutter speed to “250” that actually means 1/250th of a second. A shutter speed of “500” is 1/500th of a second. Since we are dealing in fractions a shutter speed of 500 is faster than 250 and therefore allows less light to hit the sensor.
In addition to controlling exposure, we can also use the shutter to either stop motion or show motion. A slower shutter speed can be used to show motion. For example, if we want to take a photograph of a waterfall and give it that smooth, cotton candy effect we would use a slower shutter speed to show motion.
If we were photographing a sporting event and needed to stop motion, we would use a faster shutter speed.
So, the shutter is used both in controlling exposure and also stopping and showing motion.
Electronic Shutter vs. Mechanical Shutter: What’s the Difference?
Back to the question of the differences between the electronic shutter vs. the mechanical shutter.
It’s important to understand that not all cameras have both a mechanical shutter and an electronic shutter. DSLR cameras most likely do not have an electronic shutter. Most mirrorless cameras will be equipped with both the mechanical and electronic shutters. Some of the very new mirrorless cameras like the Canon EOS R8 are ONLY equipped with an electronic shutter.
As the name suggests, a mechanical shutter is a physical mechanism within the camera. The mechanical shutter consists of 2 curtains or blades. By default, the first curtain or “curtain 1” blocks the sensor from light. When the shutter button on the camera is pressed curtain 1 drops away and exposes the sensor to light. Then the second curtain, or “curtain 2” drops down to block the sensor from light again. The amount of time between these two events happening is our shutter speed. If the shutter speed is set to 500 there will only be 1/500th of a second between the time curtain 1 drops away and curtain 2 drops down.
When comparing the electronic shutter vs. the mechanical shutter they function completely different. The electronic shutter is not restricted by any physical components like the mechanical shutter. It does not actually use a shutter at all.
The way the electronic shutter works is that the sensor “reads” the light one line at a time. Meaning, when the shutter button is pushed the first line or row of pixels is exposed. When the first line is done it no longer reads the light and it moves onto the second row. The process continues until all rows have been exposed. Our camera’s sensor has a lot of rows, but this process happens very fast. Of course, as technology improves this read speed will get faster and faster.
Electronic Shutter Advantages
The obvious question is, what do we gain by using the electronic shutter vs. the mechanical shutter?
Faster Shutter Speeds
The first is that most electronic shutters are capable of faster shutter speeds. Mechanical shutter speeds are typically limited to 1/4000th or 1/8000th of a second. Electronic shutter speeds can be much faster because it is not limited by physical components. Electronic shutter speeds may go up to 1/16000th or 1/32000th depending on the camera model.
Why do fast shutter speeds matter?
- Exposure: Faster shutter speeds can allow us to get the exposure we want, especially when we are using a very fast lens in bright light. For example, if we have a lens with a really wide aperture like f/1.4 and are photographing in really bright sun, we may need those faster shutter speeds to allow us to shoot wide open. If we didn’t have those faster shutter speeds, there would be just too much light. By being able to stop down with those faster shutter speeds we can open up with the aperture.
- Stopping Power: We may be photographing subjects moving very quickly. Maybe 1/4000th or 1/8000th isn’t fast enough to stop the motion. In this situation, it’s nice to be able to switch to the electronic shutter and use 1/16000th or 1/32000th. If we look at this photograph of the hummingbird 1/4000th doesn’t quite stop the motion of the wingtips.
Higher Frame Rates
Another advantage of using the electronic shutter is we can photograph at faster frame rates. Again, since the camera is not limited by any physical components it is capable of taking more photographs in less time. The frames per second is much faster when using an electronic shutter vs. a mechanical shutter. Mechanical shutters typically max out at 12 to 15 frames per second whereas electronic shutters can be much, much faster.
Electronic shutters operate silently since there are no physical curtains moving. This makes the electronic shutter a great option when photographing wedding ceremonies, wildlife, or any other scenario where shutter noise could be disruptive.
Elimination of Shutter Shock
Mechanical shutters can cause vibrations, known as “shutter shock”, especially at certain shutter speeds. These vibrations may result in slight image blurring, particularly when using a telephoto lens or shooting at slower shutter speeds. Electronic shutter eliminates shutter shock entirely, resulting in sharper photographs.
Related to this, mechanical shutters are harder on the camera body itself. With moving parts there is naturally going to be more wear and tear on the camera. So not only are we eliminating shutter shock to improve image quality we are also making it easier on the hardware.
Electronic Shutter Disadvantages
Electronic shutter does not come without some faults or at least some considerations. Here are the disadvantages of using the electronic shutter vs. the mechanical shutter.
Rolling Shutter Effect
One of the primary concerns with electronic shutters is the rolling shutter effect. Unlike mechanical shutters that expose the entire frame simultaneously, electronic shutters scan the sensor from top to bottom or vice versa. This scanning process can result in distorted or skewed images when capturing fast-moving subjects or when the camera is in motion. This effect is more pronounced with electronic shutters, especially at higher shutter speeds.
So again, this is much more obvious when photographing objects that are fast moving OR if the camera is panning quickly. Vertical straight lines may end up appearing bent or distorted. As technology improves and the scanning or reading speed of the sensors becomes faster this will become less of an issue.
Electronic shutters can sometimes cause banding when shooting under artificial lighting conditions. This issue arises due to the sensor’s readout process not being perfectly synchronized with the frequency of the lighting source. As a result, images may exhibit uneven exposure or subtle variations in brightness across the frame. Meaning, we will see horizonal light and dark lines running across the length of the photograph.
While some cameras have anti-flicker mechanisms to mitigate this problem, it can still be a limitation in certain situations. Aside from the anti-flicker function on the camera, we can try adjusting the shutter speed to help avoid the issue or if possible, change the light source.
Flash Sync Speed
Electronic shutters have limitations when it comes to using external flashes or strobes. Typically, the flash sync speed for the electronic shutter vs. the mechanical shutter will be about one stop slower. Just something to think about when doing flash photography, the mechanical shutter may be a better option.
Global Shutter vs. Rolling Shutter
While this article is primarily meant to explain the differences between the electronic shutter vs. the mechanical shutter, I think it’s important to bring up the topic of “global shutter” as well. A technology on the horizon, a global shutter or global electronic shutter captures the entire frame of the image simultaneously. So instead of the “rolling” electronic shutter we use now where one row of pixels is written at a time, the global captures all lines at once.
Global shutters do not suffer from the rolling shutter effect, which can cause distortion or skewing of fast-moving objects or when the camera is panning. Since all pixels are exposed simultaneously, there is no time difference between the exposure of different parts of the photograph.
Implementing global shutters is technically challenging and expensive, but I believe will be something we start seeing in the marketplace in the not-so-distant future.
Electronic and Mechanical shutters both have advantages and disadvantages and like many functions on our cameras there is a time and a place for when either could be used. Personally, I use the mechanical shutter a majority of the time, but that has a lot to do with the type of photography I do. There are situations, however, where I know it’s in my best interest to use the electronic shutter. For example, I have a camera/lens combo that is highly susceptible to shutter shock and will almost certainly introduce some motion blur into my images. To keep things nice and crisp I switch it to electronic shutter.
Bottom line, do what works best for you and the situation.
Additional Resources: Looking for more information on taking waterfall photographs? Check out this article!