If you think that a smartphone camera is a simple element that takes pictures, you are wrong. Even if you are sure that it is not as simple as it seems, you are still far from the truth. In fact, it is much more complicated than it seems. So how does the camera of a modern smartphone?
Misconceptions about the small complexity of the camera is largely due to the fact that the times when the camera was only in the most expensive devices are long gone, and now it is even in models for several thousand rubles. Of course, the quality of images of such cameras leaves much to be desired, but the camera is there, and therefore the cost of the module is very low.
However, it is worth considering that even the simplest camera can not be composed of a matrix of millions of tiny elements and focusing system with moving elements. Now imagine the size of the smartphone camera module and the complexity of these moving structures.
The matrix of any camera, along with optics, are fundamental elements of image quality. For a start, let us examine what is exactly the matrix.
The main type of matrix used in modern devices consists of light-sensitive elements assembled in blocks. The more of these elements, the more clarity the camera can provide. Of course, there are some variables that nullify the value of a large number of these elements. This may be a poor build quality, poor optics or a desire to make the matrix smaller while maintaining its light-sensitive elements.
It is worth noting that the light-sensitive elements themselves can not work without special filters applied to the surface of the matrix. These filters skip only red (Red), green (Green), and blue (Blue). That’s why the system is called RGB.
If the light of a certain color does not fall on the element, it falls on the neighboring one. This is the principle of determining the color of the picture, so the camera understands what color the point should be. Having collected several million of such points (megapixels) together, the processor processes them and collects them into the finished image.
The dual camera of the new ZTE Ahop 9 Pro allows you not only to take great photos immediately, but also to change the focus point on ready images or decide how much the background should be blurred.
Learn more about Axon 9 Pro
The size of the light-sensitive cell greatly affects the final image quality. Despite the fact that the cell size is expressed in microns, the apparent small difference of a few tenths of a micron is very significant – the larger the pixel size, the better. For example, the matrix ZTE Axon 9 Pro has a pixel size of 1.4 microns and if any other smartphone pixel size is 0.14 microns less, the difference will be ten percent.
The distance between pixels also affects the image quality. If the pixels are very small and” crammed ” very tightly, the camera can have as many megapixels as you want, but the pictures will be bad and with a lot of noise.
All this is an explanation that 40 megapixel resolution is not the best option. If you compare such a camera with a 20-megapixel camera of the same size, with the slightest decrease in the level of illumination, the 40-megapixel camera will start to lose significantly.
No matter how good was not the matrix, “glass” can negate all the efforts of its creators. As a result, you can get a picture that will have a large resolution, large size, but, at the same time, will never be clear. To solve this problem, optics work no less than on the matrix itself.
The camera lens of the smartphone is not in vain called so. This is the lens, as in the case of SLR cameras, just very small. Several lenses are used in the design of the smartphone lens. The exact number depends on the specific manufacturer, but there can be 4, 5, 7, 8 or even more.
Each lens is made of special plastic or the same special glass. Each of them collects a beam of light so that it evenly falls on the working part of the matrix. The slightest shift of one lens per thousandths of a millimeter can lead to complete unacceptability of the quality of images.
An important criterion of the lens is its aperture or aperture number. When choosing a smartphone, if you care about the camera, you should choose the one in which the number is less, for example, f/1.75. This will be significantly better than f/2.0, f/2.2 and so on. It’s simple — the lower the value, the higher the aperture and the better the camera shoots in low light.
Another important indicator will be the focal length, but now it has lost relevance for smartphone cameras. All modern smartphones are equipped with cameras that work perfectly at almost any distance from the subject. There are even models with several lenses that can work in different ways, complementing the functions of the main camera with the functions of a telephoto lens (analog of optical zoom) or, conversely, giving the opportunity to shoot panoramas.
In most smartphones, the whole structure is covered with sapphire glass or other durable varieties. After all, the slightest scratch on the glass can permanently deprive the camera of the opportunity to take good pictures.
From the function name it is clear what it is responsible for. At the dawn of camera for mobile devices, they were not equipped with autofocus, it was not so bad and allowed to photograph panoramas or objects on their background, having a sufficiently large depth of field. But time goes on and it is necessary to introduce new functions.
So there was a basic element that allows you to improve the pictures. It currently has three main types. The first is contrast. The essence of his work is to find the optimal focus to make sharp the whole image or some part of it selected by the user. For such a system, it does not matter at what distance the subject is.
The second type of autofocus is called laser. It works only at short distances and is combined with other systems to better cover the range of distances. It is able to determine the distance to the object and adjust the focus settings.
The third type of focus is called a phase. To implement it, there are additional sensors that allow the camera to get more data to adjust the focus.
The most advanced smartphones are able to combine the work of different ways of focusing on the move and even provide continuous autofocus, adjust to the changing position of the object.
Image stabilization system
If you do not consider the software method of stabilization, which has significant disadvantages, since it cuts the image and works mainly only while working with video, there is also an optical method.
For its implementation, the camera has a special mechanism. It focuses on the gyroscope readings and due to a special drive allows you to change the position of the camera module. As a result, it does not remove completely, but compensates for the shaking of the hands, allowing you to make the video smoother and the pictures clearer even at a relatively low light level.
In the most advanced smartphones the work of the systems is combined. This allows for even greater image stabilization.
White balance sensor
The cameras are equipped with a color sensor for more accurate color reproduction and more natural image.
Any type of lighting has its own color temperature, and getting to the object, it is reflected in different ways. The human eye perceives this normally and can adjust, but it is difficult for the camera to work with such changes.
The white balance can be mixed manually, but it is better to entrust it to automation, which is now developed so that it is practically not mistaken and allows you to abandon manual adjustments for greater convenience of shooting.
Number of modules
Nowadays, smartphones with one camera module produce only very confident or very low-cost manufacturers. Even relatively inexpensive models are already equipped with two camera modules.
This has a lot of advantages. The most obvious one is that they can have different focal length settings. For example, ZTE Axon 9 Pro allows you to shoot not only ordinary photos, but also wide — angle-with a viewing angle of 130 degrees. This can be very useful when you need to photograph a large company, a large building from a short distance or a panorama of nature.
As you can see, the camera of a modern smartphone is not as simple as it seems. It consists of a matrix with tens of millions of light-sensitive elements, information from which is processed separately, several perfectly matched lenses, miniature actuators and sensors.
All this makes it almost the most difficult element of the smartphone. But it is constantly evolving, because it’s no secret that when buying a smartphone, we are not least pay attention to how it can take pictures.