The imaging system of the vivo X60 series touched my physical limits

After the Google Pixel mobile phone used computational photography to slam a circle of friends, the discussion about mobile photography has risen to a new dimension. This is like the century-old battle between the Chinese Mountain School of "Swordsman and Qizong" in "Swordsman": the algorithm school is infatuated with the polished moves, while the hardware school strives to fill up its internal strength.

Now that "computational photography" is mentioned more and more times, it seems to be the ultimate choice for the development of mobile phone imaging. As we all know, photography is an art that uses light, and a camera is a tool for capturing light. The popular "computational photography" should be the "light sculptor". Without the collected light, "a clever woman can't cook without rice," Michelangelo came to no use.

▲ Carl Zeiss 50mm f1.4 ZE lens. Picture from: unsplash

In other words, even though the effect of "computational photography" is very gratifying today, it still cannot do without the assistance of powerful enough hardware. It should even be said that computational photography is only the icing on the cake for powerful imaging hardware. Different from the martial arts struggle pattern in martial arts novels, almost all manufacturers now realize that the hardware's large aperture, large aperture, etc., can be used in parallel with continuously optimized HDR or night scene algorithms, and complement each other.

Therefore, in addition to continuing to refine the later algorithms, mobile phone manufacturers are still looking for the "limits" of mobile phone hardware, exploring the physical limits of the imaging module that can be accommodated in the small-size body, such as sensor size, lens structure and anti-shake structure.

Technology is advancing, but physical optics, like an iron law, is still unbreakable. Even though the smartphone industry is a diamond in consumer electronics, it cannot violate the ancient laws of physical optics, and it is difficult to lay out whatever you want in a limited volume.

▲ Picture from: unsplash

Mobile phone imaging hardware is very similar to traditional cameras. The light is irradiated on the light sensor through the lens (mirror group), and the image sensor collects the light and converts it into electrical signal output. Therefore, the breakthrough point of the mobile phone imaging hardware is also on the sensor and mirror group.

At this stage, mobile phone manufacturers choose similar sensor sizes on products of the same level, which may be limited by the upstream supply chain, but more often they neutralize the demand for thin and light bodies and large-size sensors, which is a compromise choice. .

What has been improved for the second-generation micro-head?

In the field of traditional cameras, when the sensor area is limited, you can also make a fuss about the structure, using a five-axis anti-shake mechanism. The addition of a mechanical anti-shake mechanism can offset multi-directional shaking, and then use a lower ISO and longer shutter time to obtain a purer picture. However, the traditional five-axis anti-shake mechanism takes up too much volume. The Sony α7M2 is 6mm thicker than the α7 body, and the Fuji X-T4 is 5mm thicker than the X-T3 body.

Even if the thickness is reduced to one-tenth, it is really a bad policy for mobile phones whose internal space must be compared. Therefore, the common hardware anti-shake mechanism on mobile phones is mostly OIS optical anti-shake on the lens module. Traditional OIS optical image stabilization can offset the jitter in the translation direction, but it seems helpless when facing tilt and rotation. In the field, most common solutions for stabilization are external handheld gimbals.

Therefore, the vivo R&D team merged the handheld gimbal with the traditional mechanical five-axis anti-shake, connected the lens group and the sensor as a whole, and placed the whole in the double-ball suspension. In this way, the lens group and the sensor can move together to compensate for the translation of the X-axis and Y-axis, and achieve dual-axis optical image stabilization. Vivo calls it "micro-pan-tilt" technology, and the first model is equipped with "micro-pan tilt." The technical product is the vivo X50 series.

There are few secrets in the smart phone industry. The emergence of a new technology will often "bloom everywhere" and become the industry standard. However, there is currently only the vivo X50 series equipped with "Micro-Pan-Tilt" technology. The overall area of ​​the micro-Pan-Tilt module is larger than that of the periscope camera, which requires higher industrial design and process accuracy. This is a major reason. "Micro PTZ" has also become the core technology of vivo in the imaging field.

If we say that the innovation of the vivo X50 series lies in the "Micro PTZ" technology, and the newly released vivo X60 series equipped with the second-generation "Micro PTZ" will go a step further on this basis.

First of all, in appearance, compared with the vivo X50 series, the body of the vivo X60 series is controlled at 7.59mm (take X60 Pro as an example).

Secondly, on the basis of the X50 series dual-axis anti-shake, the second-generation micro-head of the X60 series supports compensation for X-axis translation, Y-axis translation, YAW and PITCH jitter (up and down, left and right), which can achieve the effect of four-axis camera anti-shake , Which means that under the same low-light environment, the success rate of X60 series film production is higher, and the picture is more pure.

Finally, the aperture of the main camera of the vivo X60 Pro is upgraded to f/1.48, and with the second-generation micro-head, it can capture low light more stably. In addition, for video shooting, the X60 series uses the five-axis VIS anti-shake technology on the X50 Pro, that is, the optical anti-shake of the micro-head and the electronic anti-shake implementation of the in-camera algorithm.

What did you solve with Zeiss?

Traditional imaging equipment is divided into a body and a lens. The two are a set of systems that together determine the recorded picture. Smartphones are similar, but to be more precise, they are closer to fixed-lens cameras, and the quality of the lens (lens group) also directly affects imaging.

▲ Picture from: Halide developer Ben Sandofsky

The area of ​​the mobile phone sensor is getting larger and larger. In the limited space of the body, the design of the optical lens group is actually not optimized too much. Therefore, many mobile phones with outsoles are used as the main camera. When shooting close-up shots such as documents, The appearance of blurred edges is the optical "close-up spherical aberration".

To solve it, simply replace a set of lens groups that redesign the optical structure. However, few companies in the world with optical technology precipitation get involved in mobile phone lenses, let alone targeted research and development. This is no easy task.

At the same time, optical structure is a very esoteric subject, and mobile phone manufacturers' own research and development is time-consuming and laborious, and it is not easy to achieve results. It would be better to take a "shortcut" and collaborate with world-class companies in the optical field.

The recent vivo did just that. It has reached a global imaging strategic cooperation with Zeiss, Germany, from the design and manufacture of mobile phone lenses to the optimization and adjustment of imaging effects, as well as collaboration on the hardware and software levels. The first product of the cooperation between the two is the newly released vivo X60 series, and the small blue "ZEISS" label on the camera has been identified.

Be the leader in the long track

Mobile video is a "long track". There are no shortcuts on this track. We can only rely on continuous technology accumulation. Vivo's X series is already in place.

▲ vivo X50 Pro.

From Xshot’s Sony IMX214 sensor, to X7’s "portrait" shooting direction, to the X50 series of micro-heads, and the latest X60 series with Zeiss, vivo has continuously improved its own product capabilities in hardware, and constantly adjusted on the video track. In its own way, it gradually entered the first echelon of mobile phone photography.

At the same time, in recent years, vivo has also frequently launched cooperation in the "image field". In 2014, vivo cooperated with the Chinese version of National Geographic in the United States to organize a video search for the city, discovering the beauty of the city, which lasted until 2018. Subsequently, in cooperation with "National Geographic" this year, the global imaging IP "vivo video+" was launched. They do not stay at the hardware level, but are intended to create an image content ecology.

With continuous accumulation and breakthroughs in hardware and software, vivo's purpose is very clear, in order to create top-notch mobile imaging experience for consumers.

Photographing has always been a strong demand in the smartphone industry. The continuous development of technology is to make users unable to perceive the existence of technology. No matter the scene or light, it can bring high-quality imaging effects anytime and anywhere. This is the most fundamental demand of users. Vivo has joined hands with Zeiss to continuously innovate in images, the origin of which is still based on user needs.

In order to create the thin and light preferred design of the X series, the vivo R&D team used a stacked structure to reduce the area of ​​the second-generation micro-head. For better imaging quality, they worked with Zeiss to bring a new imaging system to the X60 series. With the precipitation and accumulation of hardware technology, coupled with the continuous improvement of "computational photography", when we refer to vivo in the future, the deepest impression is likely to be "professional imaging".

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