What if your phone’s camera was much, much bigger?

The cameras on our phones won’t stop getting bigger. Xiaomi’s new 15 Ultra is dominated by an enormous ring of cameras on the back, Nothing has rethought its camera layout from scratch to fit a periscope into the Phone 3A Pro, and consistent rumors suggest that even Apple is going to strap a big ol’ camera bar onto the back of its iPhone 17 Pro models later this year. But why stop there? What if you could get all of the heft and weight of a real camera and burden your phone with it? What if we could make your phone camera much, much bigger?

That’s what both Xiaomi and Realme have attempted to do at this year’s Mobile World Congress, with two very different concept phones that each attempt to bridge the gap between a smartphone and a DSLR.

Realme’s attempt is the most familiar. In fact, its “interchangeable lens concept,” which mounts a full DSLR lens onto the existing camera island of its concept phone, is remarkably similar to a concept that Xiaomi already showed off in 2022. The phone here is itself custom, not based on any of Realme’s existing smartphones, and includes two typical cameras on the rear, plus a third, customized one-inch-type sensor from Sony with no lens on top — at least not until you add your own via a proprietary lens mount. At its core, this is similar to the approach we’ve seen for years from companies like Moment, which sells small custom lenses that attach to your phone’s camera. But bigger means better, right?

Realme has designed its concept to work with two lenses: a 73mm portrait and a 234mm telephoto, and I got to try the latter. You won’t be surprised to hear that strapping an enormous telephoto lens to one end of a phone does throw off the balance somewhat, and I wouldn’t exactly call this practical. The ergonomics are challenging: because a phone is so much thinner and lighter than a camera body, I had no choice but to grab the lens fully by the barrel. All the weight rests there, leaving my left hand trying to simultaneously grip the lens tight enough to hold the whole thing up but loose enough to still rotate the zoom and focus, with my right hand essentially unable to help. It’s awkward.

The lens mount alone is a fairly substantial bit of kit, protruding an inch or so from the phone’s back, meaning there’s no way at all to make this experience a compact one — even a pancake lens is going to feel enormous here. Realme has used a standard M mount, so in theory you can attach any compatible lens, which would really be the appeal if this ever became a product. In practice it might not be so simple, as Realme has made some tweaks to its camera app to accommodate these two specific lenses. The mounting connection is a purely physical one as well, so for now there’s no way for this to handle autofocus lenses or anything else beyond the manual.

Xiaomi’s approach solves a lot of those problems, while introducing its own. Its Modular Optical System is built around a custom version of the Xiaomi 15 with a ring of MagSafe-esque magnets on the back. A separate lens attaches to that magnetic contact point in the center of the phone, but crucially it includes its own sensor, so you’re not limited by the hardware inside the phone. It’s a modern, magnetic version of Sony’s short-lived line of QX cameras that could clamp onto the back of any phone.

The one lens Xiaomi is showing off right now is a 35mm with an aperture of f/1.4, using a 100-megapixel 4/3-type sensor — bigger than you’ll find in any smartphone, including Realme’s concept. That means more light capture, and in theory better photos. Daniel Desjarlais, Xiaomi’s director of international communications, told me that the chance to include a bigger sensor is the main reason the company is exploring this form factor.

There are two contacts within the magnetic ring, which help with alignment but also handle both power and wireless data transfer over a 10Gbps optical transmission system that Xiaomi is calling LaserLink. Unlike Realme’s physical connection, that means this lens supports autofocus, though Xiaomi still included a manual focus ring for fine-tuning. Images go through the phone’s own image processing software, so you’ll get a style that’s similar to the phone’s other photos.

Alongside enabling a bigger sensor, the other benefit of building everything into the modular lens is that it can attach to the middle of the phone, rather than having to be built on top of the pre-existing camera module. That means this feels much better balanced, and more comfortable to hold and use. Attaching and detaching the lens is a single quick action, and with no intermediary mount this is more compact than Realme’s design could ever be. I can actually imagine shooting with this day-to-day, especially if there was also the option to attach something like the grip from Xiaomi’s 15 Ultra Photography Kit.

There are downsides, of course. The magnetic attachment feels strong — Xiaomi encouraged me to hold the phone upside down by the lens and shake, and it survived the experience — but a proper camera mount will always be stronger. Desjarlais admitted to me that the magnetic connection probably rules out a full-size telephoto lens simply by virtue of the weight, though perhaps that’s for the best.

Lens options are the other downside. There’s an awful lot of proprietary tech in here, and no-one else is building modular magnetic lenses with sensors built-in. That means any version of this that ever came to market wouldn’t be interoperable with any existing lenses, which might kill half the appeal for the photographer audience it would hope to reach.

I haven’t spoken about image quality from either of these concepts yet. I wasn’t able to get my own sample photos from either device, and a few minutes at a trade show don’t give much scope for thorough testing. I absolutely believe that both will deliver better photos than a regular smartphone can, but that’s just a matter of physics — better lenses and bigger sensors result in nicer photos. The real question is whether they’d be improved enough to justify the hassle and cost a setup like this would always involve, especially as phones like the Xiaomi 15 Ultra have gotten closer and closer to DSLR quality. The reason I use my phone more than any other camera is because it fits in my pocket and it’s always there. The best lens for it will always be one that fits in my pocket too.

Photography by Dominic Preston / The Verge