What's the difference between a single camera phone and a dual camera phone?

Nowadays, the main mobile phones basically flaunt themselves as dual cameras, fearing that they can't keep up with the trend. Dual cameras have a combination of wide-angle lens and telephoto lens, and a combination of color lens and black-and-white lens. So is the effect of dual cameras really better than that of single camera? In fact, a single camera phone can also take better photos than a dual camera phone. For example, Google Pixel 2 is a single camera. At present, the test results of DxoMark, a well-known photography third-party evaluation agency, show that the imaging performance of Pixel 2 is currently ranked first among all mobile phones, reaching 98 points, setting a record for DxoMark's evaluation.

Why did Google Pixel 2 beat Niu X's Apple iPhone X, Samsung Note E8E8 and iPhone8P with a single camera? Pixel 2 scored the highest in most traditional photo and video categories of DxoMark, ahead of previous list leaders. In fact, Google's best shooting algorithm can only win the championship with a single camera. Now many mobile phone manufacturers have begun to pay attention to software algorithms. For example, Charm Blue note6 invited ArcSoft to provide customized algorithms such as multi-frame noise reduction, HDR and background blur. Make the shooting ability of Charm Blue Note6 more powerful. So it can be explained that the shooting effect has nothing to do with the number of cameras. The key lies in whether the algorithm is reasonable and whether the photos displayed are natural.

Of course, dual cameras are not useless. In the absence of software algorithm, only one double camera can be added to improve the effect and quality of taking pictures through hardware. Let's take a look at the photo-taking ability of a single camera from the real sample of Google Pixel 2.

Under the high light, the details of Google Pixel 2 are in place, the color performance is excellent, and the dynamic range is impressive, so it is an excellent camera for shooting high-contrast scenes. The details of highlights and shadows are well preserved, and the noise is well controlled.

We can see the details of the highlight area under the Eiffel Tower and the darker part under the bridge from some screenshots of the original image of 100%.

In a tricky shooting scene, the details of the bright and dark areas of Pixel 2 can show amazing results. See the original partial map of 100% below.

In low light, Google Pixel 2 camera retains fine details very well, but there is some brightness noise. In addition, in the bright backlight indoor scene, it also lost some details. In terms of dynamic range and autofocus performance, Pixel also performs very well in low light, except for some defects of uneven color indoors and in low light, and the color performance is also very good.

The indoor and low-light photos of Pixel 2 show good details and wide dynamic range.

Because Pixel 2 has only one main camera, the zoom, depth of field effect, portrait mode and bokeh are all generated by the algorithm from one or more frames of images taken by the camera. Pixel 2' s algorithm has done well in these aspects, but it is not perfect.

Compared with the real telephoto lens, Pixel 2 obviously loses details when zooming at medium and long distances, but its loss is less than that of most other single camera designs. As you can see here, at 4x zoom, Pixel 2 does a good job in noise suppression, but it loses quite a lot of details. Photos with a zoom of more than 4 times are no longer available.

For lens scoring, there are several aspects to measure the quality of photos, including the camera's ability to describe shallow depth of field (sometimes called "depth of field effect"), the ability to shoot portraits with depth of field (sometimes called "portrait mode") and the performance of the lens itself (out-of-focus shape and aesthetic feeling). In the comparison of indoor portrait photos below, you can see that the picture quality of Pixel 2 is obviously higher than that of Pixel, but the background is blurred and the scene is scattered, which is not as natural as the dual camera system of iPhone 8 Plus.