Optical quality and image algorithms stand as the twin pillars supporting the camera's capabilities.

On the opening day of MWC25, Xiaomi unveiled the future of mobile imaging with the "Xiaomi Modular Optical System," showcased through the Xiaomi 15 concept phone and an M43 prime lens camera. Coincidentally, another domestic mobile phone brand, Realme, also flexed its imaging prowess at MWC25 by unveiling its first interchangeable lens concept phone. Lei Technology was on-site at the Realme booth to provide a hands-on experience.

While both Realme and Xiaomi's modular optical systems adopt a detachable design, Realme's concept phone technically aligns more closely with Xiaomi's 12S Ultra concept phone from three years ago, which could mount Leica lenses.

Image source: Realme

Firstly, the "direct lens mounting" that Xiaomi was unable to achieve in the past remains unrealized on the Realme concept phone. According to Lei Technology's coverage at MWC25, Realme requires the installation of a relatively large mount ring on the phone before attaching the camera lens. The addition of this mount ring extends the camera flange distance, leading to a disadvantage in terms of equivalent focal length conversion.

Secondly, Realme's mount ring solution is a "cold mount," meaning there is no signal path between the phone and the lens. Consequently, the phone cannot ascertain the specific focal length, aperture, and other parameters of the lens, requiring manual focusing by the user and precluding lens stabilization.

However, Realme's mount ring solution also introduces significant improvements: Xiaomi's previous approach could not utilize a large sensor to match the lens image field, whereas Realme directly equips a custom one-inch large sensor, ensuring clarity and resolution. Additionally, the mount ring's locking structure is ingeniously designed and includes a tripod mount.

Image source: Lei Technology

For devices like mobile phones with top-heavy camera lens adapters lacking lens stabilization, a tripod is almost essential for telephoto shooting. In terms of lens selection, Realme has opted for classic Leica M lenses, offering considerable versatility even with cold mounting.

Currently, Realme offers a portrait lens with an equivalent focal length of 73mm and a telephoto lens with an equivalent focal length of 234mm, supporting up to 10x native lossless zoom. The incorporation of genuine optical lenses grants this Realme concept phone ultra-high optical magnification quality unattainable by mainstream phones, significantly enhancing depth of field and clarity. Judging solely by the sample images, it is hard to discern that they were captured by a mobile phone.

However, on the first day of MWC25, two major mobile phone brands both released their latest imaging-focused products, and the underlying trend in mobile imaging merits our closer attention.

Has Computational Photography Reached a Bottleneck?

As Xiaomi and Realme are both domestic mobile phone brands, their prominence at MWC25 has spurred many domestic imaging bloggers to share hands-on experiences of the related products. A recurring keyword in these review videos is "authenticity."

Here, authenticity does not refer to a single aspect like bokeh or detail resolution but rather to the authentic image obtained through the pure optical design of large lenses, unconstrained by the spatial limitations of mobile phones.

Let's delve into the bokeh aspect. Currently, mainstream mobile phone bokeh heavily relies on computational optics and AI deep learning. It's not that mobile phone cameras cannot achieve authentic bokeh, but under the combination of small sensors, small apertures, and short focal lengths in mobile phones, the optical bokeh effect stemming from lens characteristics is not pronounced.

Image source: Google

To render the bokeh effect visible, mobile phones often need to process the image further: phones with LiDAR or ToF sensors can use these to obtain real depth data, dual-camera phones can use parallax algorithms to separate depth data from photos, or AI algorithms can perform basic block segmentation on the image and estimate depth. After obtaining the depth map, the phone post-processes the image based on the depth information, adding additional bokeh effects to out-of-focus areas.

However, even the most accurate LiDAR cannot map high-precision depth due to sensor limitations, let alone depth estimation solely reliant on AI algorithms. This results in mobile phone portrait bokeh often appearing "fake"—not only is the cutout imprecise, but the bokeh effect also lacks depth, falling short of true optical bokeh.

Moreover, the ultra-telephoto capabilities of mobile phone sensors realized through computational photography and pixel shift (known as "pixel binning" in the camera community) cannot compare to genuine optical telephoto. Of course, the decline in image quality at the telephoto end of high-zoom lenses is also an issue the camera industry needs to address, but compared to the chromatic aberration and image distortion issues of optical telephoto, mobile phones relying solely on computation for ultra-telephoto are prone to losing details and artifacts. Incidentally, the ultra-telephoto moon shots captured by a certain brand do not belong to artifacts but rather hallucinations.

Image source: Lei Technology

Returning to Xiaomi and Realme's concept phones at MWC, although these products will not be commercialized in the near term, replacing computational photography with real optical lenses signifies that the mobile phone industry has hit a bottleneck in computational photography or has entered a stage where software algorithms alone cannot keep pace with real optics.

Of course, if mobile phone brands increase investment in AI ISPs and continue refining algorithms, there may still be room for advancements in computational photography. But from a cost perspective (both time and money), investing more in optics might be a more cost-effective choice under current circumstances.

Professional Techniques Becoming Mainstream, Consumer Products Specializing

Furthermore, Xiaomi and Realme's approach of integrating lenses with mobile phones reinforces the viewpoint Lei Technology has always emphasized: "Professional Techniques Becoming Mainstream, Consumer Products Specializing."

This concept is simply a story of "two-way progression." For ordinary consumers, mobile phones are the most everyday and accessible shooting tools; for professional photographers and enthusiasts, mobile phones also offer unique advantages in flexibility and portability.

Manufacturers continue to bring professional techniques down to consumer products, making high-threshold professional experiences accessible to more people. As consumer products continue to "evolve" with these professional features, they, in turn, inspire professional application scenarios, fostering a virtuous cycle of two-way interaction.

A typical example of this specialization of consumer products is the "Optical Module" showcased by Xiaomi at MWC25. Lately, many online comments have suggested that Xiaomi's detachable product is "over-engineered"; originally, traveling with just one mobile phone suffices, but now, besides the phone, one also needs to pack three lenses in a lens bag. However, from another perspective, for camera enthusiasts like me, traveling with one camera and three lenses is standard, and even a casual walk requires carrying a GR or RX100 in one's pocket.

And the concept of specialization of consumer products allows us to continue the traditional camera operation flow and creative experience on mobile phones, making cameras go from "essential" to "optional" and fostering boundless creativity.

Image source: Lei Technology

On the flip side, consumer mobile phone products, bolstered by professional features, are also "advancing" in reverse, enabling more non-professional users to take the first step towards higher image quality or more expressive capabilities. Xiaomi's concept phone with interchangeable lenses brings the lens system, mount ring, and large sensor, originally scattered in the professional realm, to scenarios within easy reach of users.

More importantly, the improvement in optical configuration has not increased user interaction thresholds. Whether it's Xiaomi's optical module or Realme's lens adapter solution, the system's default camera interface is ultimately invoked, with the operation flow and image tone style being no different from the system's default camera. Only the superior imaging effect reminds you that you are using an external lens.

This means a mobile phone can provide telephoto shooting capabilities, rich depth levels, and true optical quality on par with professional equipment, making "optical imaging" no longer exclusive to a select few veterans. Over time, the shooting experience accumulated by users through trial and error will spawn new demands, further propelling mobile phones towards specialized exploration.

Image source: Yi Camera

Speaking of this, I also recall another product—the Yi Camera M1 released by Xiaomi ecosystem company Yi. Frankly, this M43 camera with a dual-lens kit priced at just 999 yuan during clearance sales has poor image quality. But Yi achieved something no other international brand has:

Yi utilized a simple, intuitive graphical touch operation interface akin to mobile phones to teach users the relationship between "aperture," "shutter speed," and "ISO," using a teaching aid to guide camera novices who have only used mobile phones for photography through the most basic camera operation flow, preventing them from being discouraged by professional cameras' complex menus (especially Sony) and ultimately fostering a love for photography.

In fact, some members of the Lei Technology content team's photography journey began with the Yi Camera.

Stronger Technology Fosters a More Vibrant Ecosystem

From this perspective, "Professional Techniques Becoming Mainstream, Consumer Products Specializing" is not merely a technological evolution but an ecologically interdependent cycle of mutual empowerment.

On one hand, the design of interchangeable lenses and customized large sensors imbues mobile phone photography with "authenticity" and greater plasticity; on the other hand, the continuous surge in consumer demand for shooting experiences also compels mobile phone manufacturers to innovate ceaselessly, bringing more commercialization opportunities for professional techniques and supply chains.

This two-way drive will not only persist in the realm of mobile phone imaging but also extend to broader industry scenarios. The AI glasses that gained popularity at CES 2025 are, in my opinion, the prime example.

Image source: Lei Technology

In Lei Technology's view, the conceptual products launched by Xiaomi and Realme at MWC25 are not mere "token" technological experiments but a microcosm of the entire mobile imaging industry's progress. The signal they send is clear: mobile imaging is constantly progressing and exploring, and this path will no longer be confined to mere material stacking or algorithm development.

Against this backdrop, those seemingly radical innovations might not necessarily fail to take root. Perhaps by the next MWC, those who once doubted detachable lenses will be queuing up at the booth exclaiming, "So good!"