What are the advantages and disadvantages of optical telephoto?

What is optical telephoto? Optical zoom? Or ask telephoto?

In popular terms, telephoto is to enlarge the original scene, just like a telescope. The first function of telephoto is to see far, such as shooting birds. You can't really play without telephoto, and telephoto won't disturb the subject; Secondly, it is more convenient to cut the picture; It is easier to make a small depth of field. The disadvantage of telephoto is that the field of vision is small; It can't be displayed in a narrow place, and the focal length is long, which requires the safety shutter to be faster. If there is no anti-shake, you need a tripod.

Compared with the wide-angle impact angle, the telephoto end picture is quiet and peaceful, with the advantage of peace, but with the disadvantage of no sense of scene when sweeping the street.