There’s a lot of hype around a camera that Sony just announced: the a9 III (such an inspiring name, right? When will camera makers come up with more memorable—and, in turn, marketable—names?). What’s special about this camera is that it’s the world’s first full-frame stacked CMOS global shutter camera.
Global shutter? What’s that? Specifically, we’re talking electronic shutter, and not mechanical. Typically, CMOS sensors are read line-by-line, and not every line at once, which can cause problems like rolling shutter effect. This makes the electronic shutter less useful, as it’s more limited than the mechanical shutter; however, there are also several advantages to an electronic shutter, so sometimes it is preferable. With a global shutter, all the light sensitive sensor elements are read at the same time (not line-by-line), eliminating the disadvantages of the electronic shutter.
This is a significant step forward in camera technology, and I don’t want to diminish that, but at the same time the hype is a bit overhyped. Let me explain why.
One of the big advantages touted by those who are especially excited for this new technology is that it eliminates the need for flash sync speed. Use whatever shutter speed you desire for flash, including ultra-fast. Interestingly enough, this limitation doesn’t exist for leaf shutters, which are a mechanical shutter type found in some cameras, namely the Fujifilm X100-series. If you have a Fujifilm X100V and you are using the mechanical shutter, there’s no need to worry about flash sync speed. Granted, most cameras don’t have a leaf shutter, and leaf shutters are mechanical and not electronic; however, I found it interesting nonetheless that the global shutter solves a problem that isn’t always a problem, depending on your camera. If you don’t have $6,000 to shell out for a new camera, but you already own an X100-series model, you don’t have to worry about missing out, and you can let the FOMO rest for awhile.
Did you notice all of the qualifiers for the “world’s first” designation? Specifically, full frame and stacked CMOS global shutter. Why do you think those needed to be added? Well, the first full frame camera with a global shutter was the Contax N, way back in 2002 (it was developed in 2000, but it took awhile to come to market). The first camera with a global shutter, in theory, was developed by Kodak in the 1970’s. You see, CCD sensors, which were common before CMOS, were technically global shutter sensors. They became outdated before advancements in camera technology allowed photographers to take advantage of that aspect of them, but, technically speaking, global shutters are far from new, they’re only new to CMOS. Actually, Panasonic made a global shutter CMOS sensor back in 2018; however, the technology is newly coming to the market just now.
The promise of the global shutter is that the disadvantages of the electronic shutter are eliminated, and the need for a mechanical shutter is reduced or eliminated. The mechanical shutter has served photography pretty well over the last 150-ish years, so it’s not exactly a high-priority item to replace (in my humble opinion), but perhaps having fewer moving parts in future camera models will extend the life of those bodies (maybe). If you have a leaf shutter camera, the advantages of a global shutter is much less significant, but if you don’t, it’s a bigger deal for sure. Of course, global shutters bring their own disadvantages (most namely, it takes more processing power to read and store everything all at once). I think it’s just a matter of time before global shutter sensors are common, and perhaps as a result mechanical shutters will be much less common in future cameras.
I’m not saying that the need for improved electronic shutters doesn’t exist, or that significant advancements in the technology shouldn’t be celebrated. I’m simply stating that what’s old is new. That the hype is a little overhyped. For most people, the Sony A9 III won’t be a game-changer, or a milestone model remembered for decades and decades to come (as some are suggesting). I’m certain it will be a great camera that many will love and it will sell quite well for Sony, but for the majority of people, the differences between global and non-global electronic shutters will make little or no practical difference to them and their photography. For some, however, it will be a big deal, and for those folks, it’s worth noting and celebrating. Don’t be surprised if the X-H3 or X-T6 has this technology (I have no idea, I’m just speculating). If you have a leaf shutter camera, such as the X100V, you’re already enjoying the benefits, at least when it comes to flash sync speed and (nearly) silent operation.