Why the smartphone is a double camera?

Recently, an increasing number of smartphones with a double main chamber began to appear on the store shelves. Many consumers do not understand completely, why do you need a system consisting of two lenses. Let's try to figure out the answer to this question.

Mobile electronics is gradually improved. This is especially noticeable on the example of cameras embedded in smartphones and ordinary mobile phones. It all started with modules, the resolution of which was only 0.1 Mp. Such cameras created a tiny photographs with a high level of digital noise. Then the permission of the modules began to increase - first up to 0.3 mp, then up to 1.3 Mp, and so right up to modern 23 meters. Along the way, the creators of smartphones taught the diaphragm to disclose as much as possible - up to the value of F / 1.8. But the latest trend is the installation of two main cameras at once. The saddest for any consumer is that the system of two lenses can be constructed in different ways. As a result, a double camera gives one effect in one smartphone, and in the second is completely different. Let us find out what smartphones with a double camera are most often.

3D effect

Do you think that for the first time two lens on the rear wall of the smartphone appeared in 2015 or 2016? You are seriously mistaken! There was a time when the world of electronics literally overwhelmed fashion for 3D. Display the stereoscopic effect then learned the TVs, special accessories for 3D shooting received domestic camcorders, then the Nintendo 3DS portable console was released. Tried on a universal trend to play two large manufacturer of smartphones - HTC and LG. In 2011, they produced devices capable of displaying a stereoscopic picture to view which special glasses were not required. Also, engineers needed to teach them to shoot 3D-photos and 3D video. As a result, smartphones HTC EVO 3D and LG Optimus 3D received a double chamber.

We can easily call an approximate distance to the object due to the fact that our brain looks at the world with two eyes. And that is why the fixed smartphone will not be able to take a picture of a three-dimensional picture if only one lens is available at its disposal. The system of two cameras does not have such a problem. The lenses are deliberately located apart at the same distance as our eyes.

However, the fashion for 3d quickly passed, and the above-mentioned smartphones were not in great demand. All this led to the fact that they did not receive heirs. For several years, the devices were equipped with a single chamber.


Modern devices with a double base chamber do not know how to shoot 3D content. This is due to the fact that different characteristics have either lenses or matrixes. And even if they are exactly the same - one optics is too close to the other. Smartphones began to get a double chamber again not for the sake of stereoscopic shooting. At first, the manufacturers of such equipment were interested in the question of post-processing.

In 2011, the light saw a very curious chamber Lytro. From all such devices, it was distinguished by the fact that she offered on ready-made photos to change focus! It was possible to make a sharp object in the foreground. Did not like? We change the zone of sharpness, making a clear object located away. You could also change the depth of field, making it wider or already. All this became possible due to the special lenses system.

But in the smartphone such a system cannot be embedded, otherwise the device would turn out to be thick with the Bible. Therefore, the creators began to embed a second chamber equipped with their own optics and a matrix. If you remember your smartphones providing the ability to change focus and aperture on the finished photo, then ZTE Axon ELITE and DEXP Ixion Zenith come to mind.

As you could guess, neither Lytro did not take off (the chamber had a follower with a more pretty design, but he could not boast special sales) nor Smartphones with advanced post-processing features. Why? Just people do not want to mess with ready-made pictures. Maximum many consumers produce a photo decoration with built-in means Instagram, but no more. They want to immediately get a high-quality image. Therefore, the manufacturers of smartphones threw experiments in this regard, concentrating on the autofocus system - if it will work quickly and correctly, then a serious post-processing of photography is simply not required.

Monochrome images

Color matrices have one drawback. They have to equip by the Bayer Color Filter, which to one degree or another reduces the sharpness. If a monochrome matrix is ​​used, then the clarity is not lost anywhere. It is she who laid the base of the second chamber with some manufacturers. In his commercials, they assure that thanks to such a design, the device makes the same sharp pictures, as well as any mirror cameras.

Photo: pcadvisor.co.uk

A double chamber in Huawei works on such a system [64)] P9 . Both lens have a 27-millimeter focal length, and the same 12 megapixel matrices are hiding beneath them. Even the diaphragms are revealed to the same value f / 2.2. However, one module matrix is ​​color, whereas the other is monochrome. As a result, more sharp, both black and white and color photos are obtained. For the sake of this case, the Chinese even licensed the right to use the Leica brand known to each professional photographer.

For a similar principle, double chambers in Xiaomi Mi5s Plus and Cool1 Dual are operating. Only it can be considerably cheaper, since these devices are in no way flagships.


Compact cameras were not fully extinct only due to the presence of of the optical zoom . In the smartphones there is no such function yet - the zone is composed in the manufacture, increases the size of the device and consumes a decent amount of energy. However, limited zoom still appears in some devices. Implement this feature helps embedding two chambers with different focal lengths. The first chamber may have a standard viewing angle, while the second is reduced. As a result, the user will be available almost instantaneous switching from one option to another - what is not an optical zoom?

For this principle, the camera is operating built into iPhone 7 Plus. One of its lens has a traditional 28-millimeter focal length, while this parameter in the second optical unit is increased to 56 mm. It turns out that the user during shooting is provided with exactly two-time optical zoom. Soon, such systems will appear in other smartphones - this confirmed the exhibition MWC 2017 .

Some large companies go in a completely opposite direction. In addition to the standard lens, they embed wide-angle optics. This allows you to not bring closer, but remove the picture. So in the frame will fit more people - the image will look like that, when shooting , the action chamber. At the same time, no one bothers at some point to abandon the wide-angle shooting, returning to the usual. Such a system is implemented, for example, in LG G5.

Blur background

Many people love mirror cameras for excellent portrait shooting. In the presence of appropriate optics, such an apparatus can very beautifully blur the background. The camera built into smartphones for a long time was not capable - the minimum matrix size affected and a rather uninformed revealed diaphragm. Double camera partly solves this problem. If both modules have the same optics (the sensor resolution can be different), the device can determine the distance to the object. Then the programmatic method can be blurred everything that is behind the photographed person or subject.

The first dual chamber for creating a beautiful bokeh received HTC One (M8). In the future, this function was obtained by very many smartphones equipped with a double chamber. Including on the blur of the background, mentioned already Huawei P9, one of the chambers of which is monochrome. Unfortunately, the software is often mistaken, because of which the snapshot is not so beautiful, whatever it is when using a systemic or mirror camera. Yes, and example Samsung Galaxy S7 showed that a single camera can also blur without any auxiliary actions.

Summing up

Now you understand how dual cameras are created by what principles. Which one is the best? It is unrealistic to answer this question. Some of the buyers want to get an optical zoom, albeit two-time. Others are focused on the possibility of blurring the background. So far we can only say that you should not buy the most cheap smartphones with a double camera. The fact is that in them the second camera may well be a bout. Check it is very simple. Enough while shooting, cover one of the lenses with your finger. If nothing happened (with a different focal length, try to use zoom) - there is nothing under the optical block.

In the future, the manufacturers of smartphones will necessarily try to argue the immense. We can wait for devices with three chambers. This will allow the device and competently wash the background, and the optical zoom to provide. It is also possible that someday we will still come back to 3D shooting.