fókusztávolságot

Fókusztávolságot is a Hungarian term that translates to focal length in English. It is a fundamental optical property of lenses and mirrors. In photography and optics, focal length describes the distance between the optical center of a lens or mirror and the focal point. The focal point is the point where parallel rays of light converge after passing through a lens or reflecting off a mirror.

Focal length is typically measured in millimeters. It has a significant impact on the field of view and magnification of an optical system. Lenses with shorter focal lengths have a wider field of view, capturing more of the scene, and are often referred to as wide-angle lenses. Conversely, lenses with longer focal lengths have a narrower field of view, magnify the subject more, and are known as telephoto lenses. A lens with a focal length roughly equivalent to human vision is often called a "normal" lens.

In the context of cameras, focal length determines how much of a scene is captured and how large distant objects appear. It is a key specification for choosing the right lens for a particular photographic purpose, whether it be landscape photography, portraiture, or sports. The focal length of a lens is a fixed property of that lens, although zoom lenses allow for a variable focal length within a certain range.