Xiaomi may have been talking a lot about the cameras on its new 15 Ultra phone at this year’s Mobile World Congress, but it had another bit of mobile camera tech up its sleeves. In essence, it’s a camera unit that attaches to the back of a phone, turning the phone into the screen and brains for the camera, but providing a much bigger camera sensor and professional-standard lens.
The device, which Xiaomi calls the “modular optical system” is strictly a concept right now, but I was able to get hands-on with it in a meeting room backstage at MWC. The device is best thought of as a small camera lens, but it contains an image sensor and connects to the back of the phone. When it does, the phone is then able to use this camera unit as its main camera, in theory, significantly improving the quality of your images. I even managed to snap some test shots.
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I took a photo of my Leica Q3 43, which I’ve covered in tape for security reasons. I like the natural fall-off of focus here which looks more natural than you’d expect from a regular phone camera.
You can use the phone’s regular camera mode, including any filters or effects. I love the high contrast monochrome look.
While the Xiaomi 15 Ultra’s main camera has a 1-inch type image sensor, which is already larger than many other phones, the modular camera uses an even larger four-thirds sensor, which will be able to produce better looking shots with higher dynamic range. The optics are larger to let in more light and the aperture goes from a wide f/1.4 to a closed down f/11, with physically moving iris blades, unlike the virtual apertures employed by most smartphones. As I opened up the aperture in the settings, I could see the iris physically growing larger inside the lens.
Unlike most phone camera lenses, this lens has actual iris blades to open and close the aperture.
If all this sounds familiar, it’s because Sony had a very similar idea with its QX10 and QX100 cameras. Like the Xiaomi concept, these were lenses with sensors that connected to your phone, essentially using the phone’s screen as the viewfinder. But, Sony’s products launched back in 2013 and the technology wasn’t really ready to support them. They connected via Wi-Fi direct, which was slow and unstable, and you had to use Sony’s own app, which was dreadful.
Xiaomi’s concept is like Sony’s QX10 but reimagined for 2025. While it physically attaches to your phone with magnets, it actually connects using what Xiaomi is calling laser link technology, which is capable of transferring data at up to 10 gigabits per second, resulting in an extremely low-latency connection. The downside of this is that Xiaomi’s concept relies on working in tandem with a phone that supports the laser connection — right now, that’s also just a concept — while Sony’s can work with any Android phone.
In my hands-on time, using the lens with the phone was just as easy as using the phone’s built-in camera. When you attach the lens, you simply tap a button to switch to the lens unit, and the on-screen controls switch up to take advantage of it. Taking images with it saves them directly to your gallery as normal.
Sony’s QX10 launched over 11 years ago, but Xiaomi seems to be bringing it right up to date.
While Sony’s QX10 and QX100 were not well received, I actually really like this as an idea. It allows more dedicated photographers — like myself — to carry a much more pro-standard camera unit with them to snap onto their phone whenever they want better image quality. It’s much smaller and lighter than carrying a regular mirrorless camera with you.
As it’s a concept, there still remain a lot of unknowns, including the potential price, whether Xiaomi will build the laser connection into other phones or move to a different connection system, or if this product will ever be anything more than a bit of a novelty at a tech show.
I hope it comes to life. Xiaomi has a good record of working hard on pushing mobile imaging forward, and if it continues to work with iconic camera maker Leica, then I’ll be even more excited about the idea of strapping a Leica-standard lens unit to my phone.
