How to choose the focal length for indoor portrait photography

Personally, I think it is better to take pictures with a 50mm or 80mm fixed-focus lens, that is, if you use a lot of zoom lenses, you need to pay attention to your position when shooting with a fixed focus, and you can find the feeling by taking more shots. However, Jiao Da aperture lenses are usually more expensive. If you are using a Canon camera, it is recommended to buy a 50MM 1.8F lens to find the feeling. This is about 600 today. If it is not a 135 camera, the 50MM fixed focus can basically be used as an 80MM lens!