Xiaomi 12S Ultra Concept has a second 1-inch sensor you can attach a Leica lens to

Remember the Xiaomi 12S Ultra? That was a phone that made headlines in July by featuring a sizeable one-inch image sensor on its main camera. This device is unfortunately not available in Malaysia, but we have put the Leica-branded cameras through their paces. Not once, but twice.

It’s been a few months, but Xiaomi has dropped another bombshell with the debut of the 12S Ultra Concept, which adds a second one-inch sensor at the centre of the distinctive circular camera bump. This displaces the ultra wide camera, which has been moved off to the side, replacing the regular Ultra’s periscopic telephoto shooter.

Unlike the two other cameras with smartphone-sized lenses, the second sensor sits naked save for a sapphire crystal cover to protect against dust and scratches. Its raison d’être becomes clear once you remove the outer camera bump ring, revealing a ultra-thin bayonet lens mount. Yes, you read that right: this is a smartphone you can attach a lens to, turning it into a mirrorless interchangeable lens camera.

With this Mi-Mount, the 12S Ultra Concept is able to shoot images using Leica’s iconic M-System rangefinder lenses, mated to Xiaomi’s computational photography tech. These lenses are renown for their small size, but they can’t be attached directly to the phone due to the flange focal distance required to keep the photos in focus, so you’ll need to attach an adapter first.

Xiaomi has done some serious reengineering of the phone to be able to fit the second sensor and withstand the weight of the external lenses. The company optimised the circuitry around the sensor and stacked the two one-inch units atop each other, allowing the 12S Ultra Concept to maintain the original main camera.

It also made an alloy base that’s attached directly to the middle frame of the phone, ensuring that the weight of the lens is transmitted evenly across the entire device. Underneath sits a conductive metal sheet to dissipate the extra heat coming from the cameras.

It should be noted that since the 12S Ultra Concept uses a one-inch sensor instead of either 35mm film or a full-frame sensor employed by an M-System camera, there will be a significant crop on the images coming out of the sensor—even more than APS-C cameras using full-frame lenses.

For instance, the Leica Summarit-M 35mm f/2.4 lens (which, by the way, is the cheapest M lens you can buy, coming in at a cool RM8,830) will be equivalent to a 94.5mm lens on the 12S Ultra Concept. By the way, the 35mm f/1.4 lens used in the promo images and video costs a whopping RM25,055. Yikes.

Of course, this isn’t the first time people are putting interchangeable lenses on smartphones. Companies have been making adapters for years, and even Apple filed a patent for a bayonet lens mount on a phone back in 2014. But this is the first concerted effort from a first-party phone maker, and a pretty cool one at that.

Unfortunately for those of you chomping at the bit to buy one, the Xiaomi 12S Ultra Concept is just that— a concept—and there are no plans to put the device on sale…yet.

Related reading

• Xiaomi 12S Ultra vs iPhone 13 Pro: Does a big sensor mean better low-light video?
• Xiaomi 12S Ultra vs iPhone 13 Pro: This phone is unbelievable in low-light
• Xiaomi 12S series with Leica co-engineered cameras isn’t coming to Malaysia
• Xiaomi 12S Ultra: Xiaomi’s ultimate camera phone with a massive 1-inch sensor