How to choose the correct focal length when shooting SLR?

The answer is: there is no concept of "correct focal length", so there is no need to choose.

In normal people's understanding, the focal length of a SLR is "zoom in and out", but it is more than that. It also involves the perspective relationship.

But let's not talk about the perspective relationship here, let's talk about something simple.

For example, when shooting a landscape, you can choose a wide-angle end (for example, half width 18mm, full width 28mm), or an ultra-wide angle to show the tension of the landscape, or you can choose a telephoto end (for example, 200mm) to show part.

The photographer can choose the header (full width 50mm), or he can choose 85mm bust and 135mm head. Looking through the master's photo album, some people took busts with 135mm, some people took head shots with 85mm, and some people took figures and fisheye lenses with super wide-angle lenses.

Finally, you don't have to think too much. Discover beauty, capture beauty, and make good use of the equipment in your hand is king.