Focal-length definitions

The distance of a lens or mirror to its focal point.
noun
0
0
The distance from the optical center of a lens or curved mirror to the point where light rays from a very distant object converge.
noun
0
0
The distance of a lens or mirror to its focal point.
noun
0
0
The distance between the optical center of a lens or mirror to its focal point .
0
0
Focal length is the optical distance in millimeters between a camera lens and the sensor or film. It determines the height and width of the scene being captured, known as the "field of view."A prime lens has one focal length and thus a fixed field of view. In order to change it, the photographer has to move closer or farther away from the subject. A zoom lens has a range from wide angle to telephoto.Focal length is one of the two primary measurements of a camera lens. The other is the "aperture," which is the lens opening (see f-stop).
0
0
Advertisement
(optics) The distance at which something (e.g. a lens, mirror etc.) is in focus; in air it is the distance along the optical axis from a "principal plane" of the lens to one of the lens's focal points.
noun
0
0