What role does the focal length of the lens play in photography?

The focal length of a photographic lens plays an important role in reducing the imaging size and viewing angle. Long focal length imaging, small viewing angle, short focal length imaging, small viewing angle. For example, zoom in on distant objects and use a lens with a long focal length; On the contrary, use a lens with a shorter focal length to push the background object away. Take 135 camera as an example: 50mm is the standard lens, and under 30mm is the wide-angle lens, which can shoot a wide range of ostentation and extravagance (relatively small images); 80- 120mm is the medium focal length lens, 120- 150mm is the medium and long focal length lens, and the lens above 200mm is the long focal length lens. If you want to take a panoramic view of the sun, you need a lens with a focal length of 800 mm For portraits, a lens with a focal length of 100- 135mm is more suitable. Generally, a lens with a focal length of 50-70mm can be used all over the body. This shows a rule: if you want to enlarge the background, you need to use a longer focal length; On the other hand, if you want to push the background farther, you can use a lens with a shorter focal length to get a wide ostentation and extravagance. For more information, you can go to the photography forum to exchange information with the world novice, and see more about the influence of lens focal length on photography.