In November 2000, Sharp launched a "carrier-customized mobile phone" J-SH04 in Japan. Although the shape of this model was not beautiful even at the time, and its performance was simply not worth mentioning compared to the "King of Machines" Nokia 9110 at that time, it relied on an extremely important technological innovation and was Leave it in the annals of history forever.
Because it is the world's first mobile phone with camera function.
Looking back at history, it is not difficult to find that since cameras were added to mobile phones, major manufacturers have basically gone through three stages on the issue of "how to make mobile phones take better pictures." That is, the earliest stage of crazy superstition about pixels, the later stage of algorithm-only and AI supremacy, and now the stage of returning to hardware exploration and focusing on outsole and high-quality lenses.
To be honest, we cannot blame manufacturers for the detours they have taken in mobile phone imaging design in the past. After all, every era has its own objective technical limitations at the time. But the problem is that for today's top camera phones, when the customized CMOS is close to 1 inch in size, when the AI ??algorithm has almost used the ISP's capabilities to the limit, when 10bit or even 12bit color formats exceed the capabilities of civilian display equipment. When they are all used in the imaging system of mobile phones, what other methods can bring about a big breakthrough in the imaging performance of mobile phones?
On the afternoon of August 19, 2021, OPPO used a "Future Imaging Technology Conference" of only 19 minutes to announce their latest batch of imaging technologies that will be put into mass production. In addition to the new generation of under-screen camera solutions that Sanyi Life has reported and analyzed before, the other three technologies have been made public for the first time.
What’s more interesting is that after carefully tasting these three new imaging technologies of OPPO, we found that OPPO’s research and development direction revealed from these technologies is likely to represent the development of smartphone imaging. The next stage is one that is more pragmatic and at the same time more familiar to photography enthusiasts.
First of all, OPPO announced their new sensor pixel design
First of all, let’s start with OPPO’s new CMOS sensor. As we all know, for today's smartphones, the development of "super large soles" has basically reached a bottleneck, because a larger sensor area will inevitably increase the flange distance, resulting in the need for thicker lens modules and more protruding lenses. camera module, and a thicker body. However, if the area of ??the CMOS sensor is not increased, it is difficult to improve the single-pixel photosensitivity on the physical level.
So is there any new way to increase the photosensitivity without increasing the CMOS area? The answer is yes. That is to modify the pixel layout of the sensor, "stuff" W white pixels that do not sense color, but only sense light intensity, into the traditional RGGB pixel gaps, and turn them into an RGBW structure, which can greatly enhance the photosensitivity of CMOS.
Of course, adding W white pixels is not without cost. On the one hand, it will reduce the number of pixels that CMOS ultimately actually participates in RGB imaging, which means that in order to maintain resolution, the RGBW sensor itself must be large enough and have enough pixels. On the other hand, the traditional CMOS sensor has a group of four RGGB pixels, but after adding white pixels, the four adjacent pixels will inevitably not contain the three primary colors of RGB at the same time, which will affect the imaging quality and even produce false colors and moiré. Pattern.
In order to solve the above problems, OPPO has adopted a "hardware four-pixel-in-one" design in their new RGBW CMOS sensor, which combines the traditional four groups of pixels (that is, the actual 16 Photosensitive units) are combined into a group for imaging, thereby ensuring that each group of pixel units has complete RGB three primary colors and W pixels that greatly increase the photosensitivity to eliminate the moiré phenomenon.
On the other hand, by adding a pixel isolation layer between the photosensitive units, the problem of mutual interference between different color units is solved and the imaging purity is improved. And it is worth mentioning that the calculation of "hardware four-pixel integration" is completed directly on CMOS, so there is no need for special adaptation of the mobile platform of the mobile phone, and it can be compatible with various models.
Secondly, OPPO has brought about a big change in the telephoto "telephoto" of smartphones
In terms of mobile phone lens design, OPPO also announced a "big move" today, that is A periscope zoom lens that truly supports continuous optical zoom between the 85mm-200mm equivalent focal length.
You must know that although many models now use a "zoom multi-camera" design, for almost all mobile phones, the so-called "zoom" is just a few different fixed lenses. Just switch between focal lengths of lenses. But this will bring about two obvious shortcomings. First, the optical quality of different lenses is different, causing the color of the photo to change after zooming, which looks very unnatural; second, for those focal lengths between the two lenses, the actual It still relies on algorithmic cropping and enlarging to perform "digital zoom", so it will inevitably cause a certain decrease in image quality. For example, if a mobile phone has three zoom lenses of 1x, 3x, and 10x, then when it shoots at these "intermediate focal lengths" of 2x or 5x, the loss of picture details will be more obvious.
However, OPPO’s “continuous optical zoom lens” can solve this problem. Because it is truly designed with an array of movable optical zoom lenses inside. Driven by a long-stroke zoom motor, the zoom lens moves inside the lens to achieve a true optical magnification zoom effect without cropping or algorithmic amplification.
Not only that, inside this "continuous optical zoom lens", OPPO also uses two real glass lenses to increase the light transmittance. In fact, for current smartphones, almost all use lightweight plastic lenses to make lenses. The use of glass lenses is often considered a huge improvement in quality.
Finally, OPPO has also pioneered a new hardware solution for smartphone anti-shake.
The last new mobile phone imaging technology announced by OPPO today is about anti-shake. As we all know, the current optical anti-shake structure of mobile phones can basically be divided into three types. The first type is to design an anti-shake lens inside the lens and rely on the reverse vibration of the lens to achieve "lens anti-shake". The benefit is anti-shake The lens is very light, so the anti-shake driving mechanism can be small and the cost is not high, so it is also the most common design. But its disadvantage is that the anti-shake lens can only move in four directions, up, down, left, and right, so it can only achieve two-axis anti-shake.
The second design is to install an anti-shake driving device around the CMOS at the end of the camera system to achieve "sensor anti-shake" by driving the CMOS to rotate, tilt, and deflect. Therefore, it requires a more powerful anti-shake motor, and the cost is higher than the first design, but the advantage is that the movable range of the sensor is larger than that of the lens, so it can handle left and right tilt, horizontal roll, and up and down deflection that cannot be achieved by lens anti-shake. The type of jitter it deals with is three-axis anti-shake.
The third design is to wrap the entire camera module and use four sets of magnetic modules on the outside of the module to make it "suspended" to achieve "gimbal anti-shake". The advantage of this kind of anti-shake is that it will not cause the optical axis to shift at all, which is conducive to achieving higher image quality. However, the disadvantage is also obvious. It will limit the weight and area of ??the entire camera module, making it difficult for mobile phones to achieve ultra-large soles and Design with many lenses.
Because of this, OPPO today proposed the fourth anti-shake method for smartphones, which is the dual optical anti-shake design of the lens sensor. By arranging active anti-shake structures on the lens and CMOS at the same time, OPPO's optical anti-shake technology can achieve an effect that is 65% higher than traditional anti-shake performance.
At the same time, it also allows it to deal with shake in up to five axes at the same time, and the anti-shake compensation accuracy is 3.5 times higher than traditional models with only lens anti-shake.
None of the above are "new technologies", but why can only OPPO do it?
RGBW sensor pixel structure, built-in motor and continuously variable telephoto lens that pays attention to the quality of the lens group , the lens and sensor all have five-axis optical image stabilization with anti-shake structure. Among the three new imaging technologies announced by OPPO today, I wonder if you have found the most common points?
Yes, they are clearly inspired by good design in the traditional camera world. For example, RGBW sensors had related patents exposed by Sony and Canon as early as 2012 and 2016 respectively; such as built-in zoom motors and "internal zoom lenses" that do not change the overall length of the lens when zooming are actually already used by many high-end SLR telephoto heads. It’s a classic design on the market; not to mention the design that both the lens and the body have anti-shake and can work together. This is one of the innovative designs that Olympus, Panasonic and other M43 mirrorless manufacturers are quite proud of in recent years. one.
In other words, OPPO is actually using their design and craftsmanship to successfully miniaturize and precisely "transplant" imaging technologies that may be promising or have proven effective in traditional cameras. "Into smartphones. Compared with the "outsole" that has been difficult to continue to develop, or the "AI" that is mysterious and mysterious and may have side effects, these technologies derived from high-end cameras at least seem to be more reliable. There are many, and it is indeed possible to bring huge changes to the future smartphone imaging experience.
However, new problems arise. The above imaging technologies are nothing new in the camera field. Logically speaking, other manufacturers can also learn from them. But why didn’t we see similar technology announcements before OPPO’s future imaging conference?
On the one hand, cost and production difficulty may be one of the important reasons. On the other hand, it is not difficult to find from some details announced by OPPO at the press conference today that they have begun to explore and commercialize pixel arrangement schemes, optical anti-shake structures, and telephoto zoom technology very early. Take zoom as an example. OPPO has launched two generations of ultra-telephoto zoom models so far, and has also trial-produced a "relay" solution using multiple telephoto lenses before finally deciding to make a continuous optical zoom model. Group.
So OPPO obviously not only has the financial resources and courage to take the lead in mass-producing new technologies, but more importantly, they started early enough in "mobile phone photography" and have accumulated a lot of experience. More than enough. Perhaps it is because of this that OPPO finally chose a "return to nature" image design path. At the same time, these may also be one of the most reliable image design solutions we have seen on mobile phones so far.