gyújtótávolság

Gyújtótávolság is the Hungarian term for focal length. In optics, focal length is a measure of how strongly a lens or mirror converges or diverges light. It is typically measured in millimeters. For a simple lens, it is the distance from the optical center of the lens to the principal focus (or focal point), where parallel rays of light converge after passing through the lens. A shorter focal length indicates a stronger lens that bends light more sharply, while a longer focal length indicates a weaker lens that bends light less sharply.

In photography, focal length is a crucial characteristic of a lens that determines the angle of view and magnification. A lens with a short focal length (wide-angle lens) captures a wider field of view, making objects appear smaller and farther away. Conversely, a lens with a long focal length (telephoto lens) has a narrower field of view, magnifying distant objects and making them appear closer. The focal length also influences the perspective and depth of field in an image. Standard lenses typically have a focal length around 50mm on a 35mm film camera, providing a field of view similar to human vision. Understanding focal length is essential for photographers to control composition and achieve desired effects in their images.