linseformelen

The lens formula is a fundamental equation in optics that relates the focal length of a lens to the distance of an object from the lens and the distance of the image formed by the lens. It is derived from the principles of geometric optics and applies to thin lenses. The formula is typically expressed as:

1/f = 1/v + 1/u

Where:

f represents the focal length of the lens. The focal length is a characteristic property of a lens, indicating how strongly it converges or diverges light. It is the distance from the optical center of the lens to the principal focus.

v represents the image distance. This is the distance from the optical center of the lens to the point where the image is formed. A positive value for v typically indicates a real image formed on the opposite side of the lens from the object, while a negative value indicates a virtual image formed on the same side as the object.

u represents the object distance. This is the distance from the optical center of the lens to the object. By convention, the object distance is usually taken as negative when the object is placed in front of the lens (on the side from which light is incident).

The lens formula is a powerful tool for calculating the position and nature of images formed by lenses. It is used in various optical instruments, including cameras, telescopes, microscopes, and eyeglasses. The sign convention used with the lens formula is crucial for obtaining correct results, as it distinguishes between real and virtual images, and between converging (convex) and diverging (concave) lenses. For a convex lens, the focal length (f) is positive, while for a concave lens, it is negative.