Blendenverfälschung

Blendenverfälschung, also known as lens flare, is an optical phenomenon that occurs when light sources in a scene are reflected and scattered within a camera lens. This scattering can manifest as bright circles, streaks, or polygonal shapes that appear in the image, often superimposed over the intended subject matter.

The effect is caused by light bouncing off the internal surfaces of lens elements, as well as off the diaphragm blades. Anti-reflective coatings on modern lenses help to minimize this, but they cannot eliminate it entirely. The intensity and appearance of lens flare depend on several factors, including the strength and position of the light source, the design of the lens (number of elements, shape of elements, presence of coatings), and the aperture setting of the camera.

Lens flare can be seen as an undesirable artifact that detracts from the image quality, obscuring details and adding distracting bright areas. However, in some artistic contexts, particularly in cinema and photography, it is intentionally employed to create a specific aesthetic. Directors and photographers may use powerful light sources, such as the sun or stage lights, to deliberately induce lens flare, adding a sense of drama, atmosphere, or a stylistic signature to their work. The characteristic polygonal shapes often seen in lens flare are a direct result of the shape of the camera's aperture.