First there was optical image stabilization (OIS), then they said electronic image stabilization (EIS) does just fine, and now we’re talking about Sensor-Shift Stabilization (let’s call it SSS). Last year’s iPhone 12 Pro Max had SSS, but the tech giant has put the feature on the entire iPhone 13 lineup this year. Which means that we have to explain what SSS really means, how it differs from OIS and EIS — for SEO purposes if for no other reason. They all have one primary function, which is to compensate for possible hand shakes when you’re clicking a photo.
Let’s get the simple difference first…
Before we get to the brass tacks, let’s bring this definition to one short line.
OIS stabilizes images by allowing the lens to move on its axis, while SSS does so by moving the sensor instead of the lens. EIS, on the other hand, uses very advanced software in order to stabilize the image.
Ok, that was a paragraph. Sorry.
What is OIS?
So, as explained above, OIS is about moving the lens. In this, the lens is placed in the camera module in such a way that it can move along an axis. Sometimes this is two-axis movement, meaning it can move left and right or up and down, while at a four-axis OIS would allow the lens to move in all four directions. Moving in all four directions is obviously better, at least in theory.
Basically, if your hand shakes slightly to the right when you’re shooting a photo, the phone can compensate by recognizing that shake and moving the lens to the same side. It does so by using electromagnets and sensors. As a result, the final image isn’t as blurry as it would have been without OIS.
Here’s a video to help visualize all this.
What is EIS?
EIS, on the other hand, takes the image and zooms into it in a way that it’s now larger than the sensor itself. The software then scans the image for any signs of movement and moves the image in the opposite direction to counter it. Since it is entirely software-based, the effectiveness really depends on how good the software is. Case in point, Google uses a combination of EIS and OIS in order to stabilize images on its Pixel smartphones, and we all know what a stellar job those phones do.
What is SSS?
Back to the iPhone 13 series then. Like OIS, SSS also uses magnets and sensors to move something inside the camera module. But instead of moving the lens, it moves the sensor to compensate for hand shakes.
YouTuber JerryRigEverything tore down a phone to show you SSS in practice.
Wait, if all of them stabilize images, then what’s better?
No matter what anyone tells you, there’s no one correct way to do this. An accepted idea amongst pro photographers is that OIS and SSS are better than software. Because you cannot fix with technology what you broke by being human. However, the choice between SSS and OIS doesn’t have a this or that answer.
Instead, there are pros and cons…
For example, when pro photographers who use multiple lenses for imaging can specifically choose the OIS version of each lens. And each lens maker can specifically optimize the impact of stabilization for their lens. Smartphone cameras also have external lenses nowadays, but it’s nigh impossible to find smartphone lenses that have OIS built in, meaning creators who add multiple lenses will struggle to resolve the phone’s own lens with an external one.
This is especially important for the Pro iPhones, which are squarely targeted at creators and film makers, who do use specialized lenses on phones. Since the magic happens on the sensor level for SSS, pro users can theoretically choose external lenses and still take advantage of stabilization.
Having said that, OIS stabilizes the image on a lens level. And the image that the lens sees is what you see on the viewfinder, which means you can see a stabilized scene even before you click the photo. However, sensors come into play after you press the shutter button, which means you can’t see its impact on the viewfinder while you shoot the photo. Imagine using a telephoto lens where subjects are automatically brought closer, wouldn’t it be better if the image was stabilized while you shoot instead of better?
What this should tell you is that if all you do is post photos on social media for friends, these differences will be of little consequence for you. Both OIS and SSS do help in enhancing low-light imaging, and the effectiveness of a phone maker’s overall camera software is much more important for most of us. For pros though, this difference can be important.