Tønneforvrengning

Tønneforvrengning, also known as barrel distortion, is a type of geometric optical distortion that occurs in lenses. It causes straight lines to appear to bend outwards from the center of the image, resembling the bulging shape of a barrel. This effect is most noticeable at the edges of the frame and is common in wide-angle lenses. The distortion is caused by the lens elements not being perfectly aligned or having non-uniform refractive properties. In photography, tønneforvrengning can be intentionally used for artistic effect, but it is often considered an undesirable artifact. Digital image editing software typically includes tools to correct or mitigate barrel distortion. Conversely, pincushion distortion is the opposite effect, where straight lines bend inwards towards the center. The degree of tønneforvrengning is dependent on the focal length of the lens, with shorter focal lengths generally exhibiting more distortion. Understanding and correcting for tønneforvrengning is important for applications requiring accurate geometric representation, such as architectural photography or surveying.