Stray light

As stray light, a diffuse light is used in photography, which is caused by reflections inside of lenses and camera bodies.

Effects

The stray light results in a brightening of the image, which is visible particularly in the shadow areas. The image contrast is decreased, the image appears dull and washed out. A related phenomenon is the mapping of reflections within the lens. This effect can be observed especially in multi-element zoom and wide angle lenses. Often these reflexes have the shape of the lens iris.

Countermeasures

To reduce the normally unwanted stray light, various techniques may be combined:

• Housing components and components of the lens barrel, which lie in the beam path, to the extent possible, painted matt black.
• Surfaces are ribbed or equipped with light aperture, and the bellow of classic cameras provides a very efficient suppression of the scattered light.
• Lens shades prevent the development of scattered light by the side of light is avoided in the optics.
• The optics of lenses are reimbursed.

• Tool against stray light

Black matting and ribbing for reflection reduction

Light aperture in the optical path of the lens

Lens coating

Other meanings

Under stray light one understands:

• Light scattering in the atmosphere by aerosols, dust, mist
• Light scattering from rough surfaces
• Rayleigh scattering