How to achieve 5x optical zoom for mobile phone camera?

Yes, it stretches inside the phone, but it's not visible outside. The optical zoom of mobile phone adopts periscope lens. At present, the maximum zoom magnification reaches 10 times.

Of course, this kind of lens is only configured on relatively high-end mobile phones, and ordinary low-end mobile phones are all digital zoom. Now the pixel of mobile phone is very high, more than 40 million, so the digital zoom image quality is calculated by software, and the image quality is not bad.

There is a sentence that vividly explains mobile phone photography. I don't know if you have heard of it. Now the mobile phone photos are not taken, but counted.