Question

what is the focal length of a lens

Answer 1

HI

It is the focal length of the lens which is the distance between the lens and the image sensor when the subject is in focus

Answer 2

hi mate,

Answer : The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power.

A positive focal length indicates that a system converges light, while a negative focal length indicates that the system diverges light.

Definition: Focal length. Focal length. Focal length (shown in red) is the distance between the center of a convex lens or a concave mirror and the focal point of the lens or mirror — the point where parallel rays of light meet, or converge.

i hope it helps you.