Light scattered by the surface of the lens, by contaminants on the lens surface such as water or dust, or by reflections inside the lens barrel or the camera body interior. This scattered light causes bright patches on the image, and is typically seen if the lens is pointing towards a bright light source like the sun. Flare can also result in an overall lowering of contrast across the entire photo.
Lens coatings are one way to reduce flare significantly. Other lenses have flare-cutting diaphragms, which are physical barriers built into the lens to reduce unwanted light reflections. Lens hoods reduce the amount of direct non-image-creating light hitting the surface of a lens, and are invaluable at reducing flare, and good lens hoods also have black flocked interior surfaces to reduce reflections. Good flare control is typically an indicator of a high quality lens.
cf. contrast, coating, lens hood.
Entry last updated 2002-04-04. Term 492 of 1487.
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