Now the photo taking effect of mobile phones is getting better and better, even reaching the level of some low-end digital cameras. However, because mobile phones are more lightweight and fashionable in design, there are few mobile phones with optical zoom on the market at present. The lens of these mobile phones with optical zoom is also quite large. When combined with the body, you will feel that the phone on hand is more like a card machine. If you call with such a mobile phone, you can guess what people around you will say. Therefore, in order to see the distance clearly on the mobile phone screen, we have to use digital zoom more often.

Altek A14 Leo phone with 3x optical zoom

Digital zoom, also known as digital zoom, is called Digital Zoom in English. Digital zoom is to enlarge the area of each pixel in the picture through the processor in the digital camera, so as to achieve the purpose of magnification. This method is similar to using image processing software to enlarge the area of the picture, but the program is carried out in the digital camera, using "interpolation" processing method to enlarge a part of pixels on the original image sensor, and using interpolation algorithm to enlarge the image of pixels on the image sensor to the whole picture.

The optical zoom relies on the optical lens structure to achieve zoom, so the optical zoom will not lose the quality of the picture. The effect of digital zoom using difference algorithm is certainly not as good as optical zoom. Let's see how digital zoom works.

The following two photos are taken by iPhone 4S, and the photo on the right uses digital zoom for shooting.

We can clearly see that the picture on the left is obviously better than the picture with digital zoom. The picture with digital zoom is quite blurry, with more noise, and many details in the picture are lost.

Maybe someone will ask that since digital zoom is similar to the amplification method of image processing software, the effect of digital zoom is good? Or the effect of image processing software is good?

In the following picture, the left picture is an ordinary picture, and the right picture is a digital photo. Then we will use Photoshop to enlarge the left picture.

The left picture below is the photo after Photoshop amplification, and the right picture is the photo of the original digital zoom. It can be seen that the difference between the two photos is not very big, but a closer look shows that the digital zoom photos on the right have more noise. In addition, the photos after digital zoom processing are also relatively blurred, as can be seen from the text on the Sony memory stick. Therefore, in most cases, digital zoom is meaningless. When taking a picture, if you can shoot near, you can shoot near. Using less digital zoom can improve the image quality.