At the dawn of camerastate for mobile devices camera not equipped with autofocus. It wasn’t so bad and allowed to take panorama photos or objects on their background, possessing a fairly large depth of field. But time passes and it is necessary to introduce new functions. So there was the main element that allows improving pictures.
When choosing a phone with a good camera, many pay attention to the number of megapixels. However, more important and useful to look at other factors that have equally serious impact on the quality of the photos. Among them — the type AF camera of a smartphone. Currently he has three main types.
This is the most common type, which is equipped with smartphone cameras, low and medium price segment. The essence of his work is to find the optimal focus to make sharp the entire image or some part of it selected by the user. A special microprocessor constantly reads and analyzes the image from the image sensor and moves the lens to locate the areas with the highest contrast.
The last thing is the only downside of contrast autofocus is slow work. Because search takes time, and it can be done only after analyzing the entire image and return the lens back, the frame can “get away” for the camera to catch focus.
This type of focus to date is predominantly used in budget smartphones such as the Samsung Galaxy J7, Huawei Honor 6A and others.
The more advanced type of autofocus, which is able to determine the distance to an object and adjust settings focus. It works quite interesting: the smartphone sends a thin strip of light that is reflected from various surfaces and returned. After that, the camera detects makes calculations (time of the laser is multiplied by the speed of light) and determines the distance to the object, and thus cannot focus.
It seems to be very technologically advanced, but there is a downside. The laser auto focus works only at small distances and aligned with other systems for coverage of range of distances. Therefore, manufacturers now combine contrasting and laser autofocus.
Laser autofocus feature mainly smartphones LG, but there are exceptions: the same flagship Huawei P20 Pro.
Phase detection autofocus
To implement additional sensors that allow the camera to capture more data for focus adjustment. It is much faster contrast, the camera supports continuous autofocus, it requires powerful hardware. Often phase detection autofocus available in smartphones to high-end segment. Among them, View Honor 10, P10 Huawei and Sony Xperia XZ.
The phase type is well suited for shooting objects in motion — true, he’s still not as fast as laser. The most advanced smartphones capable to unite the various ways to focus and even provide continuous autofocus adjusts to the position change of the object.
By the way, another type of autofocus is not so widespread, as it is limited to the Samsung smartphones is the Dual Pixel. This significantly improved phase detection autofocus instead of the 5-10 % of the pixels used for autofocus, uses all 100% of the pixels. So he found a use in the newest Samsung smartphones.
Obviously, the camera of a modern smartphone is not as simple as it seems. And autofocus makes it almost the most difficult element of the smartphone.
The material was prepared with the support of the store SmartPrice