Ask Huawei's P9 optical zoom (that is, to enlarge an object and make a picture bigger is called zoom, and people who play photography are all.

The P9 is equipped with two identical lenses with120000 pixels and 78 FOV. The effective focal length is about 3~4mm and there is no optical zoom function.

The real optical zoom is that the effective focal length of the lens changes, which makes the magnification of the object larger. For example, when the optical zoom value is 10F, the focal length can be changed from f to 10F. At present, most smart phones only have digital zoom, which only upsamples images. Although the object has become larger (so-called enlargement), its clarity has decreased. The real optical zoom is magnification, keeping the definition unchanged.

Due to the limitation of size, few mobile phones use optical zoom at present. Both Samsung and ASUS have had continuous optical zoom phones, but they have not received much attention and are too bulky. Apple 7plus pioneered the use of two fixed-focus lenses to achieve zoom, and used image processing methods to achieve transitional fusion to achieve lossless zoom. But you should know that this idea is not originally created by Apple, but by some startups.