focal length

US /ˈfoʊ.kəl ˌleŋθ/
UK /ˈfoʊ.kəl ˌleŋθ/
"focal length" picture
1.

焦距

the distance from the center of a lens or curved mirror to its focal point

:
Adjusting the focal length changes the magnification of the image.
调整焦距会改变图像的放大倍数。
A longer focal length results in a narrower field of view.
更长的焦距会导致更窄的视野。