Huawei P20 Pro attracted a great amount of people's attention as soon as it was launched. Its camera is eye-catching with special designs, and it adopts the largest CMOS image sensor among current smartphones out there. This is absolutely a shining point for those believing that for a sensor, larger is better.
P20 Pro comes with triple cameras, in which the major one is an RGB wide-angle lens with 29mm equivalent focal length, F1.8 aperture and "40MP" resolution. The 40MP is still one thing to make clear. The second camera is monochrome wide-angle, with 27mm equivalent focal length, F1.6 aperture and 20MP. This one's 20MP doesn't need to have a quote on it. The RGB with mono cameras is a typical design of Huawei. P20 Pro also owns a third camera, with a long focal design three times longer than the main camera, namely 81mm, F2.4 aperture and 8MP. As for the Leica lens highlighted repeatedly by Huawei, it doesn't really matter.
What is really interesting is that, the main camera's image sensor, which is said to be Sony IMX600, features 1/1.7 inches. Perhaps it is not a biggest one in the smartphone industry history, but it is biggest among current models. Generally speaking, a larger size of sensor means better image quality. So far, the mainstream high-end smartphones mostly use sensors of 1/2.4-1/2.8 inches, so then 1/1.7 inches is twice the size. Based on these information, it is reasonable to consider P20 Pro's image quality as better than mainstream smartphones even without using it. As the main camera sensor has a size so large, and the phone body isn't designed to have a outcrop, it can be understood that the main camera doesn't own the OIS ‘ͺ indeed it is really hard to be packed in.
This sensor uses the Quad Bayer array which is rare to be seen. It differs with traditional structure as 2*2 pixels group in a square share the same color filter, output as one basic unit. The advantage is that, the units in subarray can sense light for whether a short or a long time identically, making a more delicate overall effect, and can also be HDR sampling. P20 Pro can output 40MP and 10MP images. We noted 40MP specially. So how does 40MP come? If 2*2 pixel units are used as one basic unit, namely the normal mode, the output will be 10MP; and if 1*1 pixel is the basic unit, then the output will be 40MP.
Camera is the most important selling point for P20 Pro, and Huawei also take full advantage of its best resource on advertising how great P20 Pro can photograph. DXO Mark Mobile gives P20 Pro high marks as 109, while iPhone X scores 97. The difference of 12 points means a higher level. After all, iPhone's camera has always been the standard model to be copied, studied and imitated by major manufacturers. So, this must be the first time that iPhone is surpassed with a big gap. Of course, this is just a DXO result.
P20 Pro's focusing system is apparently different than before. For former models, it is hybrid based on multiple focusing systems, while P20 Pro runs with 4D Focus. In terms of the so-called 4D, 2D refers to the hybrid focusing of PDAF and contrast AF, along with the depth, namely 3D, and finally adding time information. It is designed to predict the objects to be captured, in order to achieve effective tracking focus. This focusing resolution was first provided by Sony in 2014.
Comparing to the popular dual pixel AF, P20 Pro has no advantage on focusing speed, but the difference on the speed is hard to notice combining with the swift pre-focus. The biggest progress on P20 Pro's focusing experience is that the focusing logic has been much optimized, which makes P20 Pro try to seek for the object in a bigger central area. After locking, if you move the phone to let the subject at the golden mean, camera would track the subject automatically. These little improvements make P20 Pro's focusing experience as good as Samsung Galaxy S9.
P20 Pro has three rear cameras, but none of them has same focusing experience. The main camera has the best focusing, only out of focus once in a while when in backlight. The monochrome camera must be in the same old way, being out of focus occasionally in low light. And the telephoto camera responds slightly slower.
P20 Pro's metering differs according to various scenes. Its actual performance is great, as white objects hardly overflows in bright light. Yet in large aperture mode, the metering may be a little bit brighter. In low light, the metering can be accurate, but the objects irradiated by point light sources may overflow.
Presently, there is no smartphone that can cope with the metering in all scenes, so it is necessary to keep the manual intervention method. P20 Pro supports focus point weighted metering which is really sensitive and has great impacts on the final image, making the intervention space enlarged and the operation relatively difficult. Both automatic and professional modes provide exposure compensation tools with plus or minus 4EV range and 0.3EV to adjust. Perhaps the range is not so large in fact but definitely sufficient. The operation under automatic mode is quite similar to iPhone's. yet that under professional mode is not.