The battle of billions of pixels: What are the mobile phone manufacturers competing for?

Recently, Xiaomi introduced Samsung's first 64-megapixel sensor GW1 at a future imaging technology communication meeting held in Beijing. This sensor will be first installed on the Redmi mobile phone (Realme will also reportedly release a new mobile phone equipped with this sensor).

In addition, Xiaomi will also work with Samsung to launch the first ultra-clear mobile image sensor with up to 100 million pixels, which will become the world's mobile phone camera with the highest photo pixels, highest resolution and resolution. In this regard, some commentators and analysts believe that Xiaomi will be able to challenge Huawei, which currently ranks first in the smartphone market in terms of photography, by leveraging its high-pixel selling point.

Sony vs. Samsung: The battle of pixel fundamentals

As we all know, the basic hardware of smartphone camera function, CMOS, is basically monopolized by Sony and Samsung, and Sony occupies the majority of the market. The so-called pixel number is an indicator of CMOS. The xxx million front and rear cameras advertised by mobile phone manufacturers refer to the pixel number of Sony or Samsung CMOS. This indicator is basically irrelevant to mobile phone manufacturers. The decision is made by Sony and Samsung, that is, their basic strength in CMOS is the basis. So what are the respective strengths of Sony and Samsung in the field of CMOS?

Taking the current highest 48-megapixel as an example, last year Sony launched the IMX586 image sensor to the market (currently adopted by most domestic mobile phone manufacturers), which increased the resolution of mobile phone cameras to 48 million pixels. Subsequently, Samsung, which ranked second in the market, also released the GM1 image sensor with a nominal 48-megapixel resolution.

Although both are 48-megapixel image sensors, they sparked a discussion on "real or fake 48-megapixel" in the domestic market at the beginning of this year. The origin is that Sony IMX586 supports the output of 48-megapixel full-size photos, while Samsung GM1 (S5KGM1) outputs 12-megapixel photos by default, and can only interpolate and calculate 48-megapixel photos, and the resolution is also different. In fact, the photodiodes of both are indeed 48 megapixels, and both use Quad Bayer array pixel arrangement (commonly known as four-in-one pixel technology).

The difference between the two is that the image processing hardware of the image sensor stack sensor of Sony IMX586 will first perform the remosaic operation, and then transmit the captured RAW format data to the ISP part of the mobile phone SoC for regular image processing operations. This reflects that Samsung has a gap with Sony in ISP processing algorithms and high-speed analog readout circuit design. Of course, this is just an example of Sony's technology leading its competitors.

In addition, Samsung also lags behind Sony in CMOS technology. Sony uses the silicon-on-insulator process, which requires precision grinding of the silicon substrate of CMOS and then mechanical processing of the circuit on it, while Samsung deliberately avoids the precision grinding process, which is the most complex in the BSI process, and directly uses ordinary silicon for packaging. Therefore, the thickness of its substrate was 50 times that of Sony's.

The only benefit is that the cost is only 25% of Sony's. However, the tolerance and sensitivity will be affected. According to industry insiders, Samsung is at least two generations behind Sony in COMS technology.

According to data released by TechInsights in March this year, Sony has the largest number of patents in the field of image sensors, and its patent accumulation in the analog and digital fields is particularly rich, which also proves from one aspect that Sony has an advantage over Samsung in this field.

Of course, we are not disparaging Samsung here. After all, Samsung is currently the second largest image sensor manufacturer after Sony, and it has a great momentum of catching up. The most typical example is the aforementioned 64-megapixel sensor GW1 and the upcoming 108-megapixel image sensor.

It is unknown how Sony will react to this. Some industry insiders said that Sony should have a 64-megapixel product on the way, but it has not yet been released to the public. However, according to the aforementioned comparison of Sony IMX586 and Samsung GM1 with the same pixels, even if the number of pixels is the same, there is still a gap between the two.

This also explains why Sony IMX586 is mostly used in mid-to-high-end phones, while Samsung GM1 is mostly used in mid-to-low-end phones. This is somewhat similar to Qualcomm and MediaTek in the field of mobile phone chips. When the chip hard indicators are almost the same, in actual mobile phone applications, MediaTek is often a level lower. There is still a substantial technical gap behind this.

In addition, from the top 48-megapixel flagship phones ranked by DxOMark, almost all of them use Sony's IMX586 (such as Honor 20 Pro and OnePlus 7Pro, currently ranked fourth, and Xiaomi 9, ranked ninth). The ASUS ZenFone 6, currently ranked second in the front camera photography evaluation, also benefits from Sony's IMX586 (Note: ZenFone 6 uses a rotating camera, and the rear camera rotates to become the front camera).

Deep customization and optimization are the key to differentiation and leadership of mobile phone manufacturers in photography

Since the basic CMOS, which is closely related to mobile phone photography, is in the hands of Sony and Samsung's upstream supply chain (mobile phone manufacturers must use it), does it mean that mobile phone manufacturers have lost the space to improve and form differentiated competitive advantages on their own?

Taking the above DxOMark list as an example, people may wonder why Huawei, which has the best mobile phone photography (such as P30 Pro), Samsung's recently released Samsung Galaxy Note 10+ 5G, which has recently entered the first place on the list, and Apple, which has always enjoyed the best reputation for photography, are not mentioned?

Don't be anxious, because these three mobile phone manufacturers have ranked first on the DxOMark rankings more than once, and they present a staggered competitive situation. More importantly, the reason why these three companies are like this is that they use deeply customized CMOS, or optimization, or both in mobile phone photography, thus becoming the representative of mobile phone manufacturers to achieve differentiated competitive advantages in photography.

I wonder if the industry still remembers that Huawei's mobile phone reputation in photography originated from the P20 series of mobile phones released at the beginning of last year, especially the P20 Pro, which topped the DxOMark mobile phone photography list as soon as it was released. It was not until the end of last year that the Mate20 series took over, and then the P30 series succeeded at the beginning of this year. After a generation and a half (from P20 to Mate20 Pro and then to P30 Pro), Huawei has dominated the list for nearly a year.

During this period, Apple and Samsung, as the main competitors, have also released a generation of mobile phones, but they have never been able to shake Huawei's first position in photography. What is the reason?

It should be stated that there are many hardware factors that affect mobile phone photography (such as lens module, material, ISP processing capabilities, etc.). However, given that the CMOS sensor is one of the most basic and important hardware that determines the quality of photography, and due to the generational differences in COMS itself, it is also the easiest to reflect the deep customization and optimization capabilities of mobile phone manufacturers. Therefore, when we analyze, we mainly focus on the comparison of CMOS parameters and the final performance in mobile phone photography to look at the important value of deep customization and optimization.

As shown in the figure, we can see the mainstream CMOS used by the flagship phones of current mobile phone manufacturers. Careful readers will find that the Sony IMX600 used by Huawei is only used in Huawei phones. The reason is very simple, this is a CMOS customized by Huawei from Sony.

Judging from the three main indicators that affect the performance of CMOS, namely sensor size (the so-called sensor size that is more powerful), number of pixels, and pixel size, except that the number of pixels is slightly lower than the IMX586 released last year and adopted by this year's mainstream flagship phones in China, it is far ahead of its competitors such as Samsung and Apple in the other two indicators that are more important than the number of pixels (Samsung's Galaxy S9 and Note 9 last year are suspected to use Samsung's ISOCEEL S5K2L4, and Apple's iPhone XS Max last year is suspected to use Sony's IMX363. The parameters of the two CMOS are basically the same, and the number of pixels is 12 million). This has become the key to the fact that Huawei P20 Pro and Mate 20 Pro equipped with this CMOS have always occupied the first place in DxOMark's mobile phone photography rankings, and it also confirms the importance of the exclusive customized CMOS hardware itself.

However, as Sony's IMX586 began to enter the flagship market this year, Huawei's P20 Pro and Mate20 Pro, which had previously adopted IMX600 and had always been ranked first, were finally surpassed by the Honor 20 Pro and OnePlus Pro7 equipped with IMX586. However, due to the release of the P30 series at the beginning of the year, and with the help of the outstanding performance of the P30 Pro in taking pictures, Huawei once again ranked first in the DxOMark mobile phone photography ranking, and continued this advantage to the Samsung Galaxy Note 10+ 5G released by Samsung not long ago.

Here comes a seemingly confusing result, that is, when Huawei's customized Sony IMX600 is ahead of IMX586 in main parameters (such as sensor size and pixel size), why did the P20 Pro and Mate20 Pro lose to the Honor 20 Pro and OnePlus Pro7 equipped with IMX586, but the P30 Pro surpassed it?

In fact, there is a small misunderstanding here. It is generally believed that Huawei P30 Pro still uses the customized IMX600, but it is actually IMX650. Although the main parameters are the same as IMX600, such as the same maximum 48 million pixels, 1/1.73-inch sensor and 1.0/2.0 pixel size, it has added quite challenging innovations.

The most important manifestation is the use of RYYB filter to replace the RGGB filter with a tradition of more than 40 years, which increases the amount of light entering by 40% (we understand that it has the effect of increasing the size of the sensor in disguise), and the maximum sensitivity reaches ISO409600. In a completely dark environment, as long as there is a trace of light, enough details can be captured (Note: night shooting is one of the biggest selling points of P30 Pro). But the problem that follows is that due to the use of RYYB filter, it is prone to negative effects of color cast (such as yellowing). For this reason, Huawei reportedly spent nearly 3 years researching algorithms to solve this problem, continuously optimizing it, and finally overcame this negative effect.

From this point of view, IMX650 is more like an upgraded version of IMX600. In the process, Huawei has greatly improved the performance of IMX650 through customization, CMOS-level re-innovation and algorithm optimization, and has thereby widened the gap with Sony IMX586 which uses an open version. It is not surprising that it has regained the top spot in the DxOMark mobile phone camera rankings, which also proves that efficient customization and optimization actually have a considerable threshold.

Next, let's look at Samsung and Apple. Compared with mainstream Chinese mobile phone manufacturers such as Huawei, they are the few manufacturers that lag far behind in CMOS indicators in terms of photography. For example, Apple's iPhone XS Max and Samsung's latest Galaxy Note 10+ 5G still use 12-megapixel CMOS, far behind Huawei's current P30 Pro's 40-megapixel and other domestic mobile phone manufacturers that use Sony IMX586's 48-megapixel CMOS.

Not only the number of pixels, but also the sensor size and pixel size, there is a big gap with Chinese mobile phone manufacturers such as Huawei. That is to say, in terms of CMOS, an important hardware that determines the mobile phone's photography capabilities, Samsung and Apple are far inferior to domestic manufacturers such as Huawei.

So the question is, why is there such a big gap in hardware, but the gap in the final film quality is very small, and in most cases even surpasses Chinese mobile phone manufacturers?

Take the Galaxy Note 10+ 5G version, which was recently released by Samsung and tops the DxOMark mobile phone photography rankings, as an example. The 12-megapixel ISOCEEL S5K2L4 it uses is a product of the S7 era and has been in use to this day. It even surpassed Huawei's P30 Pro, which shows the strength of Samsung's algorithm optimization.

Similar to Samsung, Apple's iPhone has also maintained the 12-megapixel level for many years. The main parameters of the Sony IMX383 suspected to be used are almost the same as Samsung's ISOCEEL S5K2L4, which is also inferior to Huawei. However, the actual quality of the photos is almost the same as Huawei, which is also due to Apple's advantage in algorithm optimization.

In fact, careful readers will find that although Huawei's customized IMX600, including Sony's latest IMX586, has considerable advantages in sensor size and pixel number compared with Apple's IMX383 (including the Samsung ISOCEEL S5K2L4 of the same level), they have two different performances in pixel size.

For example, the original pixel sizes of IMX600 and IMX586 are 1.0 and 0.8 μm respectively, and after the four-pixel-in-one technology, they are 2.0 and 1.6 μm respectively; while the pixel size of IMX383 has only one value (without the four-pixel-in-one technology), that is, the original pixel size is 1.55. It can be seen that in terms of original pixel size alone, IMX363 is larger than IMX600 and IMX586.

In this regard, some industry insiders believe that the so-called four-pixel-in-one is not as simple as a 0.8μm pixel suddenly becoming a 1.6μm large pixel: the surface area of ​​four pixels is indeed larger than that of one pixel, but it still cannot be compared with a real large pixel, because pixel synthesis, ADC design, and the surface area sacrificed by the pixel interval have brought many negative impacts on the finished film, such as it will be more difficult to restore the true color, and the resolution will not reach the actual nominal pixel number level.

Another point that cannot be ignored is that whether it is the 40-megapixel IMX600 or the 48-megapixel IMX586, the default output is 10 million and 12 million pixels respectively through the four-pixel-in-one technology. Therefore, from the perspective of actual film production, the difference between IMX600, IMX586 and IMX383 is far less than the nominal parameter.

From this, we can see that Samsung and Apple have been persistent in optimizing and polishing 12-megapixel CMOS for many years, and have a deep understanding of photography technology and practicality. In this regard, there is still a certain gap between domestic manufacturers and them.

In addition, according to an analysis report in an investor memo by financial company Cowen, the rear camera components of iPhone XS/XS Max are about $34.5, while Samsung Galaxy S10+ is $44, and Huawei P30 Pro is as high as $56 (about 376 yuan). In other words, judging from a camera module alone, Samsung is 1.3 times more expensive than Apple, and Huawei is nearly 1.7 times more expensive than Apple.

It is not difficult to see from this that the outstanding performance of Huawei P30 Pro in photography has indeed played a significant role in the investment in photography-related hardware. It also reflects from one side that compared with Samsung and Apple, Huawei still has room for improvement in optimization algorithms.

Customization and optimization continue, who will become the new king of photography?

After Samsung Galaxy Note 10+ 5G surpassed Huawei P30 Pro to become the new champion of DxOMark mobile phone photography ranking, Huawei (including Honor) and Samsung now occupy two seats in the top 5 of the list, evenly divided. Both parties have gone through about half a year, through their own customization and optimization, the rankings have changed alternately, the competition is fierce, and the level of competition is evident.

By the end of this year, Samsung's flagship phones will have been released, and Huawei's flagship Mate 30 series and Apple's new generation iPhone 11 will be released soon.

According to information revealed by various parties in the industry, the Mate 30 Pro in the Mate 30 series will usher in a major upgrade in photography. The most eye-catching is that two of the three cameras will be 40-megapixel 1/1.73-inch and 1/1.55-inch pixel sensors.

Judging from the basic data, its CMOS is still based on IMX600 and is a further upgrade on this basis, especially the 1/1.55-inch sensor. The industry has to wonder how Huawei has achieved a larger sensor than IMX600 again, or has it deeply customized the CMOS again? In short, the larger sensor will expand Huawei's leading advantage in night shooting.

In addition, it is equipped with two of the largest cameras in the industry, and it is exciting to see what new features the combination of the two will bring to photography.

As for Apple's new iPhone 11, there is a rumor that it will continue to polish and optimize the algorithm at the 12-megapixel level, just like Samsung, to squeeze out the potential and value of this camera as much as possible. There is also a saying that it will be upgraded to 22-megapixel, 21-megapixel, and 8-megapixel lens groups. If so, coupled with the strength of Apple's algorithm optimization, its photography level is bound to be significantly improved.

In addition to the above-mentioned camera competition between Huawei, Apple and Samsung, the recently released 64-megapixel ISOCELL GW1 smartphone from Samsung may also join the competition, as Xiaomi and Realme have both announced that they will release smartphones equipped with GW1. In addition, according to Korean media ET News, the upgraded version of Samsung A70, A70s, will also be equipped with GW1 first.

I wonder what the industry has seen from these scattered information?

What we see is that this 64-megapixel ISOCELL GW1 is a universal version of CMOS, rather than an exclusive deep customization of Xiaomi or Realme. As for the difference between the exclusive deep customization and the universal version, we have already analyzed it in the above-mentioned Huawei's deeply customized IMX600, so we will not repeat it here.

In addition, considering that Samsung first applied it to its own mid-range mobile phones rather than flagship phones, is this COMS really mature? It is also questionable how much redundancy there is in the subsequent optimization by related manufacturers.

There is another important point. As we mentioned earlier, there is a big technical gap between Samsung and Sony in image CMOS (such as the previous dispute over true and false 48-megapixel cameras). Therefore, it is definitely biased to judge that the 64-megapixel ISOCELL GW1 is the best CMOS at present and can bring better photos based solely on the number of pixels.

In fact, judging from the main CMOS parameters of the 64-megapixel ISOCELL GW1, it has no obvious advantages over the IMX600 (including the upgraded IMX650). The 1/1.7-inch sensor is almost the same as the 1/1.73-inch IMX600 (this is worth affirming and important); the pixel size of GW1 is 0.8/1.6, which is less than the 1.0/2.0 of IMX600.

It only has an advantage in the number of pixels, but considering that the final output is only 16 million pixels after the four-pixel-in-one technology, it is only 6 million higher than the 10 million pixel output of IMX600, far from the 24 million gap between the nominal 64 million and 40 million.

However, as previously rumored, if Huawei Mate30 Pro really has a 1/1.55-inch large-bottom CMOS, then the GW1, which just matched the 1/1.73-inch large-bottom of IMX600, will fall behind again. By then, the deeply customized and optimized IMX600 or IMX650 will still be ahead of GW1. Coupled with Huawei's own advantages in algorithm optimization, it is highly likely that Xiaomi and Realme models will surpass the 64-megapixel GW1 in actual photography performance.

Finally, let’s talk about the more mysterious cooperation between Samsung and Xiaomi, which may launch the world’s first mobile phone with a 100-megapixel sensor in the future.

Here we might as well quote the previous industry comments on Samsung's 64-megapixel GW1. Michael Kaschkel, CEO and President of Zeiss, said in an interview with the media that the smartphone industry (high-pixel development) has now encountered bottlenecks in processing speed, noise reduction and cost. He believes that with the current level of development of smartphones, mobile phones do not need sensors above 40 million pixels, and currently they cannot fully utilize these functions. If this view is extrapolated to 100 million pixels, the challenge will be even more severe.

In fact, judging from the fact that Huawei, one of the top three mobile phone camera manufacturers, has been working on a maximum of 40 million pixels since last year, and the "friction" between Samsung and Apple, which has been stuck at 12 million pixels for many years, in the eyes of these big guys, they all have their own standards for the meaning and value of excessively high pixels for mobile phone photography.

To sum up, from the 40-megapixel level that started last year to the 64-megapixel level that is about to be released this year, and to the 100-megapixel level that has been exposed, the main players behind the battle are the two major CMOS manufacturers, Sony and Samsung. In this process, the mobile phone manufacturers are competing with each other in terms of deep customization and optimization capabilities, which is also the key to determining who will become the new king of mobile phone photography.