focal length

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

distance focale

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.
L'ajustement de la distance focale modifie le grossissement de l'image.
A longer focal length results in a narrower field of view.
Une distance focale plus longue entraîne un champ de vision plus étroit.