The Xiaomi 12S Ultra offers an incredible camera with a 1-inch sensor

The Xiaomi 12S Ultra’s camera is a remarkable achievement: it’s one of the few smartphones to offer a 1-inch type sensor. Relatively speaking, that’s a huge sensor for a phone, and bigger sensors generally lead to better image quality.

Pitching the 12S Ultra side-by-side against some of the current class leaders in smartphone cameras, there are clear situations where the bigger sensor makes the difference. But more than anything, it highlights just how advanced the imaging systems from Apple, Google and Samsung are, even with smaller sensors. The future of mobile imaging won’t be won with better hardware alone.

First, let’s cut the housework a bit. A 1-inch type sensor is often referred to as a 1-inch sensor for convenience, but that doesn’t mean the sensor is literally an inch across or diagonally. It’s an old naming convention that has something to do with TV camera tubes. What matters here is that a 1-inch-type sensor is much smaller than what you’ll find in a full-frame camera, but significantly larger than the sensor in almost any other smartphone camera. That’s the same size as the sensors used by Sony’s RX100-series cameras – so putting a 1-inch sensor in a smartphone camera potentially puts it on level ground with the best traditional pocket cameras than the money can buy.

There are three rear cameras: the 50-megapixel main, a 48-megapixel ultrawide and a 48-megapixel 5x telephoto.

And as with other specs, the 12S Ultra’s main camera boasts a 50.3-megapixel resolution with a stabilized f/1.9 lens. By default, it creates 12 megapixel images from those 50 megapixels. There’s also a stabilized 5x telephoto (a 120mm full-frame equivalent) with a 48-megapixel sensor and a 48-megapixel ultrawide. Xiaomi says it co-designed the camera with Leica, and the camera app offers two Leica-branded color processing profiles: Leica Vibrant and Leica Authentic. Video recording up to 8K/24p is supported, and around the front there’s a 32-megapixel selfie camera.

Oh, and there’s a phone attached, but we won’t go into that here. It’s only sold in China, and as such I haven’t really been able to test it as a phone.

Why is sensor size so important? For starters, it allows for larger pixels, which collect light better. Depth of field is also a bit shallower, allowing more creative control over the focus in the background of your shot.

It also means that the lens it’s attached to can be larger, and both handsets will gather more light than a smaller lens/sensor combo. Smartphone cameras use multiple frames and computational methods to compensate for their relatively small sensors and cameras. Even so, starting with more image information gathered by a larger sensor could make a big difference in very low light or how the camera handles moving subjects in low light – major challenges for smartphone cameras.

The 12S Ultra is capable of incredible images, but it’s not the promised land

Combining a large sensor with the benefits of computational photography is something of a promised land for smartphone imaging. A Google Pixel 6 Pro already takes impressive photos in very low light with Night Sight, but it could be even better if the system had better data to work with from a larger sensor. The 12S Ultra is capable of incredible images, but it’s not quite the promised land.

Looking at some comparison images of the iPhone 13 Pro Max, Pixel 6 Pro, and Samsung Galaxy S22 Ultra, I have to look closely to see where the 12S is able to capture more detail. It’s easier to see in areas of shadow detail, especially in the scene below, where more leaves are visible in the greenery rather than lost in shadows. I also prefer the way the 12S Ultra’s image is exposed; the ground-level lights aren’t blown out like they are in the Pixel 6 Pro image. The images in the sliders below are 100% crops for comparison.

The Xiaomi (left) shows more detail in the water feature and dark green parts than the Pixel (right).

The 12S Ultra also does a little better than the iPhone 13 Pro Max. It’s subtle but the fine details in the bottles are just a bit clearer. The 12S Ultra also retains color detail in shadows where the 13 Pro can’t quite latch onto and overwhelms them with blacks.

The Xiaomi’s image (left) shows finer detail and retains more color in shadows than the iPhone’s (right).

The Samsung S22 Ultra uses a 108-megapixel sensor for its main camera, which it also uses to produce 12-megapixel images. Even when competing with the Samsung with twice the pixel resolution, the Xiaomi 12S Ultra does a better job of resolving very fine details, like the chain-link fence in the background of the image below.

The links in the fence are visible in Xiaomi’s photo (left) but are mostly smoothed out in Samsung’s image (right).

This is all very impressive, but to see a noticeable difference I have to look at both at 100% magnification. If you just take snapshots and share them on social media, you will never see the difference. On top of that, the 12S Ultra faces many of the same challenges as every other smartphone camera. Mixed lighting can sometimes lead to strange exposure choices.

Good photo in portrait mode, good baby.

And a 1-inch sensor is larger, but it naturally won’t give you the kind of blurry background portraits that large-sensor cameras can unless you get really close to your subject. So it uses portrait mode, like all other smartphone cameras, and the results are inconsistent.

Sometimes they look fantastic. In moderate indoor lighting, I took some of my favorite portrait photos of my 10 month old that I’ve taken with any smartphone. To be clear, I take a lot photos of my child with many different phones. Portrait mode is cropped by default, but you can choose from three different “professional lenses” with different pre-selected color profiles to switch things up quickly: 35mm black and white, 50mm “swirling bokeh” and 90mm soft focus . I thought they would be fancy, but I like them more than I thought. If it’s the product of Leica influence, then I guess I’m a fan.

In a different situation with a few people in the background, portrait mode photos look much worse. He struggles to distinguish my subject from the people in the background and catches a wandering arm and leg in focus. The Samsung S22 Ultra does much better in the same situation, although its results are certainly not perfect. Portrait mode is a mixed bag for the 12S Ultra, as it is on virtually every other smartphone camera we’ve seen so far.

The 12S Ultra had trouble identifying my subject.

Not perfect, but the Galaxy S22 Ultra does much better.

Overall, though, I really enjoyed shooting with the 12S Ultra, and let myself be trusted in more situations than I would with any other smartphone camera. That might not be entirely fair either. I think knowing that I was working with a larger sensor convinced me to use it in more ways than I would with any other phone camera. Even so, it held up surprisingly well for a lot of those use cases, like taking a picture of my husband tossing our child up in the air or using portrait mode in less-than-stunning light with a moving subject. I had a lot more keepers than I expected in those two situations.

This may be partly due to the color processing, which is actually quite pleasing. I wouldn’t consider it distinctly Leica, and there are a hundred ways to achieve similar color on another phone camera through processing or third-party apps. But I usually take what I get from the native camera app, and I like what’s here.

That’s a lot of camera.

But the biggest impression I got from the experience is the quality of cameras like the iPhone 13 Pro Max, S22 Ultra, and Pixel 6 Pro with much smaller sensors. It relegates most of the benefits of the 12S Ultra to 100% viewable pixel-level detail. What these other phone cameras do with computational photography to create such a narrow gap is very impressive. If that 1-inch sensor goes into Pixel and Galaxy phones with such strong compute imaging chops, well, that’s a very exciting prospect.

Photography by Allison Johnson/The Verge