Huawei P9 Dual Sensor - How Huawei bold idea are making sense

Dual sensor might be the trend now and even if no one can safely say who actually started it, there are many iteration of the technology that have been available for a while. Dual camera purpose have been varies from creating focus changing effect up to even creating 3D photo but Huawei have up the ante with their unique take on it.

What is unique about Huawei dual sensor system is the introduction of a full fledged Monochrome sensor. Some might argue of what could a black and white camera do as most photo end up in colors, well that is what this article would try to explain..

Any digital camera, be it on DSLR, compact camera or mobile devices have one thing in common, they are color blind. So for this camera to detect color (and take photo), the photo sensor are layered with light color filters so that the color blind sensor now can detect what color it is.

How Digital Camera See Colors
It all starts with how CMOS sensor of smartphone records color. Smartphone camera sensor usually uses the RGB Bayer array.

However, phototube only receives photon but cannot recognize colors. So color filter is required for collecting color information. The collected colors are then recorded by pixels and calculated through demosaic algorithm to generate an image with colors.

As can be seen from the above picture, much light is wasted, and only certain electromagnetic spectra are able to fall on the sensor underneath the color filter, resulting in low light sensitivity and poor resolution. For example, when recording a monochromatic image in red, the resolution will be reduced four times.

How Monochrome Sensor helps?

(Left)  RGB, (Right) RGB + Monochrome

To solve the problem of insufficient incoming light, Huawei add a monochrome camera and adopt a dual-camera solution. The RGB camera (color) is for recording color information, and the monochrome camera (mono) is for capturing silhouettes and details in high resolution. The light sensitivity and resolving power of monochrome camera are superior due to the absence of color filter. Dual camera solution combines strengths of monochrome camera and RGB camera that lead to better image quality.

So how do these two cameras cooperate? And what are the advantages of dual-camera compared to one RGB camera? The three tests below best illustrate the advantages. The tests are simple: cover either camera and take pictures, then compare them. You can try to do it yourself.

Test One: take pictures with RGB camera and monochrome camera covered respectively, and then take one more with neither camera covered. Please take pictures both under normal light and in darkness. Then compare the pictures.

The picture has a higher resolution, finer details, larger dynamic range, better clarity and it is brighter, proving the advantages of dual-camera: RGB camera is for restoring colors and monochrome camera is for bringing more brightness and finer details to pictures. The monochrome camera not only contributes to higher resolution, but also gives better light transmittance and sensitivity. Pictures taken with dual-camera are superior compared to those taken with single RGB camera in terms of details, clarity and brightness.

What else?
I can take stunning monochrome pictures, in monochrome mode, Huawei P9 is capable of providing the best experience of shooting in monochrome with the monochrome camera. While in normal mode, the monochrome camera and the RGB camera work together and combine their strengths such as the high resolving power, transmittance of monochrome camera and RGB camera’s ability to record colors, to produce images with better quality.

dual camera have its issue and nothing is bigger than focusing speed, with two different lenses, many of sensor type focus are render useless as there might be conflicting information given by both sensor. To mitigate any focus issue, Huawei have integrate 3 (three) different method of focus, Laser, triangulation and contrast detection. Laser focus is the quickest of the bunch but it would only work well within a limited range and there is where image triangulation and contrast detection comes to play.

Huawei even have a dedicated depth processing that would determine how far the subject are and also help the camera software to create stunning Bokeh effect.

Is this the best camera phone?
If tangible detail such as pixel count and sensor size are important to you than this isn't the best camera phone available but it is close, very very close. The software algorithm co engineered by Huawei and Leica can create stunning photo almost on a regular basis because of the high contrast photo and highlights. For most camera enthusiasts, this phone is as close to a DSLR control as you can be with it Pro Camera settings.

From what we found, the high dynamic contrast on each photos taken are not something you would normally found on any camera phone and that by itself is an engineering marvel by itself.