I’ve been a professional photographer full-time for almost a decade and have witnessed tremendous improvements over the years. It’s come to a point where the latest camera release garners no excitement from me. But there’s one elusive feature that I’ve been waiting years to see make its way into my cameras—the global shutter.
What is a Global Shutter?
A global shutter is an electronic shutter that reads the entire sensor in one instant. These days, most cameras have a mechanical shutter and an electronic shutter. The mechanical shutter is the one that goes “keh-chek” when you press the shutter. That is the sound of physical shutter curtains opening and closing in front of the sensor—hence the mechanical name. The electronic shutter simulates a mechanical shutter by capturing the same information through an electronic process. Because it’s electronic, it can be completely silent.
The electronic shutter records the data from the sensor in a line-by-line fashion. Meaning, it processes some lines on the sensor, then the next ones, then the next, until it makes it down the entire sensor. Regardless of the shutter speed, this process takes longer than the true time of exposure, which causes a lot of issues. Let’s go over the problems that current electronic shutters create.
Problems With Electronic Shutters
Rolling Shutter
Rolling shutter in video is a jello-like distortion that occurs during panning. The same effect can be seen in photographs, often when photographing a fast-moving subject. In both instances, the electronic shutter’s inability to capture the entire sensor at once is the problem.
Banding from Artificial Light Sources
If you’ve ever used your silent shutter indoors, you probably ran into significant banding in your images. This is the result of photographing a flickering light source such as CFLs or low quality LED with an electronic shutter. While the flicker isn’t visible to the naked eye, if your shutter speed is fast enough the result will be a banding pattern. The distinct lines captured are the rows of pixels being captured at different moments.
Sync with Flash
Most cameras will not trigger a flash. Flash is deactivated when you use your camera’s electronic shutter. There’s no point to it firing because the time it takes for the entire sensor to be captured would far exceed the duration of the flash pulse. The result would be only a portion of your photo showing the effect of flash.
Benefits of Global Shutter
A global shutter would resolve all of the above. There would be no rolling shutter. There would be no distortion when photographing fast-moving subjects. Artificial light would not cause banding. Your flash could sync with a global electronic shutter. With all of those issues gone, there is no need for the mechanical shutter which only creates additional benefits.
No More Shutter Shock
Shutter shock occurs when the vibration of your mechanical shutter moves your camera enough to affect the clarity of your exposure.
No More Mechanical Shutter Wear
The biggest indicator of a camera’s wear and tear is the shutter actuations or shutter count— meaning, how many times the mechanical shutter has opened. By removing the mechanical shutter, you are removing the most commonly serviced part in a camera. Imagine having a camera with 750,000 exposures and having no concern that it will break soon. I’m ready for that reality.
High Speed Sync Becomes Irrelevant
How High Speed Sync works and why it’s necessary could be an entire article itself, so I’ll skip to how this would change. A global shutter could sync with flash at any shutter speed without the need for High Speed Sync. This means the efficiency loss of High Speed Sync would be gone and your strobes would be more capable at high shutter speeds.
What’s the Catch?
Beyond losing the beautiful sound of a mechanical shutter, the only catch is that we don’t know what size camera— or what capabilities of a camera— will be sacrificed to achieve a global shutter. Our only reference point at the moment is the cinema camera industry, where the global shutter has made a lot of recent progress in terms of size and cost. One example is the RED Komodo, a $6000 2.1lb box that sports a global shutter on a 6k, 19.9 MP Super35 sensor. 19.9 MP is relatively low for the photo industry and Super35 is smaller than full frame. That tells me there’s still a long way to go before we see this tech make its way into a compact mirrorless camera body.
Who Will Do it First?
Canon and Sony are the major forces currently pushing camera technology forward, but the race to the global shutter is anyone’s game. The limitations are currently speed of data transfer and the heat associated with moving data so fast. It’s for those reasons that the global shutter will most likely first appear in a lower megapixel body geared towards video. I also think it’s likely that the global shutter will debut on a sensor smaller than full frame. You hear that Micro 4/3? It’s your time to shine.
Written by Rob Hall