The focal length (FR or ƒ) is the distance between the optical center of the lens and the camera sensor. The larger the focal length, the larger the image scale projected by the lens onto the sensor, the smaller the focal length, the smaller the image scale. We can say that a lens with a large focal length enlarges objects, as if bringing them closer to the photographer, and with a smaller focal length – it reduces, moves objects away.
The focal length determines the angle of the image of the lens (angular field). For a lens with a large focal length, the image angle is narrow – enlarging objects, a telephoto lens fills the entire frame with them. A Continue reading