108 MP vs 12: how cameras work in smartphones

Manufacturers began to make smartphones with 108-megapixel cameras, but this does not mean that they will shoot better than 12-megapixel models

At the end of summer 2019, Samsung announced the world’s first sensors for smartphones with a resolution of 108 megapixels – ISOCELL Bright HMX. Xiaomi is ready to take them into service. If you believe the rumors, it is on their basis that the main camera of the new flagship of the Mi Mix 4 company will be built – they plan to launch it in October this year. Prior to this, the Chinese Apple introduced the relatively inexpensive Redmi Note 8 Pro with a 64-megapixel camera – this is the maximum value today.

At the same time, the entire line of new iPhones, which were shown at the Apple presentation on September 10, received a set of cameras of 12 megapixels each. An unprepared user will immediately consider that the reference American flagship will take photographs and record videos many times worse than the Chinese, which also costs significantly less. But practice proves the opposite. The resolution of the matrix is ​​far from the most important thing in the camera, and now we will explain how it is generally arranged.

The matrix is ​​made up of pixels that collect light

The number of pixels in the camera does not yet indicate whether it shoots well or not – this is the main thing that you need to remember when choosing a new smartphone. It’s better to immediately watch the shooting tests in real conditions – they will tell more.

The two main nodes of any camera are the matrix and the lens. On the first of them are the notorious pixels that collect the light coming into them. This is necessary to create an image. The larger each such point, the better. Its size affects the amount of light that it can collect. There are tiny gaps between the pixels, due to which noises appear on the final photo, so they should be as large as possible.

It is a pity that the matrix, which is especially important for smartphones, has a limited area. It can not fit a lot of large pixels for high-quality photos. But there can also be few points, because the detail of the image, which in the end will turn out, depends on them. That is why it is very important to maintain the right balance between the number of pixels and their size. It turns out that installing a sensor at 108 megapixels may not be a good idea just because of their size.

At the moment, matrices for cameras in smartphones are made by Sony, Samsung and OmniVision. The first two companies are considered to be of the highest quality, but even the latter sometimes get very sensible models.

ISO

One of the main characteristics of the matrix is ​​its sensitivity – ISO . It is responsible for the brightness of the picture in different conditions. Modern smartphones make it possible to adjust this indicator during shooting in order to achieve the necessary creative effect. Well, even on the iPhone you can adjust the ISO level, but for this you need third-party software . By default, Apple closes this feature so as not to complicate the process of obtaining photos.

Of course, it is also important to consider the size of the matrix or its diagonal. Not only the number and size of pixels that can fit on it depends on it – it also affects the maximum ISO level and many other characteristics.

Focusing, clarity, viewing angle

Professional photographers believe that the lens is much more important than the camera itself. This is not surprising, because it is through the lens that the light initially passes, which then hits the surface of the matrix with its pixels.

The main objective of the lens is to get as few distortions and a picture of maximum quality as possible. He is also responsible for focusing, focal length, sharpness, viewing angle and so on. Typically, the lenses that are used in smartphones have several lenses. Some of them may be plastic, others glass. The latter are often used in the most expensive gadgets – sometimes they are even protected by sapphire spraying so that they are less scratched.

Among the most significant characteristics of lenses, the focal length and aperture size are well known to photographers who regularly acquire new ones and change old ones. But in the case of smartphones, there are some nuances.

Focal Length of Camera

For example, the vast majority of smartphones use a fixed focal length – the distance to the subject. That is why they often do not have the adjustable optical zoom that large cameras use. On some smartphones out of the situation thanks to additional modules. One of the first to do this was Apple, which added imitation of double optical zoom in the iPhone 7 Plus.

Most often, the zoom in smartphones is implemented on a digital basis. In this case, the device takes only part of the information from the required area of ​​the matrix and stretches it to the entire frame. Yes, the quality is worse, but there are no options. By the way, precisely because of the small size of the matrix in smartphones, standard cameras are wide-angle. This enables manufacturers to use a larger aperture size, which also affects the quality of the image.

Aperture of Camera

Aperture size is a characteristic of the width of the hole through which light enters the camera’s matrix. It is indicated by the letter “f” and is written next to the number – the smaller the better: f / 11, f / 8, f / 5.6, f / 4, f / 2.8, f / 1.8. Many modern smartphones have f / 2 and f / 2.2 apertures. In the top models, there may be f / 1.8 and f / 1.7, and Samsung flagships generally use cameras with its adjustable size – almost the same as in large cameras.

By the way, the blur of the background, which can be achieved with the camera, depends on the size of the aperture – this is especially important in portrait shooting. Since it is relatively small in smartphones, manufacturers have come up with soap backs using neural networks. To do this, they connect additional cameras that measure the distance from objects, or try to do this only with the help of trained artificial intelligence.

Auto and other types of focusing in smartphones

Depending on the type of focus, smartphones are configured differently to shoot a particular subject. The purpose of this process is to clear the image with good sharpness. But the process itself can occur in different ways.

  • Firstly , there are gadgets with and without autofocus support. In the first case, you can sharpen a specific object, regardless of the distance to it. It will turn out to take pictures both near and far. In the second case, focusing on something relatively close is no longer possible. Comes to shoot something only at a distance from the lens. This option is noticeably worse, but smartphones today are found only in the budget segment.
  • Secondly , if the camera does not have special sensors for automatic focusing, it uses contrasting sections of the image in the viewfinder for this. To make it easier and cheaper than anything, but it does not always work correctly. Worst of all, it’s obvious that objects with little contrast are given, as well as moving frames. In flagship smartphones, this is now practically not used.
  • Thirdly , phase detection is considered the most common auto focus. Today it is used by Apple, Samsung, and many other companies. For it to work, there are special additional sensors on the edges of the matrix, the picture on which should coincide – this indicates that the focus is set correctly. This system works quickly enough, so even active sports can be photographed with it.
  • Fourthly , recently they also use focusing with a laser, which works on the principle of reflected light. It is considered the most accurate, but very limited in effective distance – at a distance of 3 to 5 meters, this system still works, and then the beam is strongly scattered. That is why laser focusing is used only in conjunction with phase focusing. When the first one fails, the second one is connected – this is the only way to guarantee accuracy.

At the moment, the development of phase focusing is considered the most promising. Manufacturers are trying to increase the number of sensors that are responsible for it – the more there are, the more accurate it is.

Why image stabilization is needed and how it works

To get a sufficiently clear photo, the device must be stationary during shooting. If you hold it in your hands, this is almost impossible to achieve. That is why stabilization is used: digital or optical.

Digital stabilization (EIS) is based on the software mechanisms of the smartphone. In this case, only the central part of the matrix is ​​used for the photo, and the surrounding pixels remain in reserve. Information from them is needed if the device sees that the device is shaking. Then the image moves along the sensor and it feels like the frame is not moving. The results are not bad, but they rarely reach optical stabilization.

Optical stabilization (OIS) interacts with the lenses that are used in the lenses of smartphones. They move in the opposite direction from the direction of shaking. If we are talking about four-axis stabilization, then the lenses can move both in horizontal space and in vertical. The matrix that the light hits can also move, but this method is used less often. Optical stabilization can be used simultaneously with digital.

Yes, stabilization significantly affects the quality of the picture, which in the end is obtained. This is clearly visible when shooting a video, but it also applies to photographs. If stabilization is not provided, it is unlikely to get a good shot.

Neural networks and other features of modern cameras

In general, in addition to the matrix resolution, the camera has a ton of other characteristics that you should pay attention to, for example: the lens aperture size, focal length and type of focus, stabilization, and so on.

However, today it is very difficult to assess the real capabilities of the camera, even with all these characteristics before your eyes. All due to the fact that recently in the first place more and more software mechanisms come out.

For example, before, everyone was sure that to get a portrait shot with the background blur effect, you need an additional camera or related sensors. But Google was able to prove the opposite to everyone by implementing this system with a single module. Moreover, it is her smartphones from the Pixel line that do all the other gadgets for the quality of evening shooting without any additional sensors.

The latest trend is the simultaneous use of three or more modules for the main camera. Today it is not only in expensive flagship smartphones, but also in cheap ones. We talked about this in more detail in a recent podcast release .

As a result, it is best to watch real smartphone tests in real environmental conditions. We do these in our regular reviews . This is the only way to evaluate the strengths and weaknesses of cameras – not by the number of megapixels.

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