Neutral density filter.
A filter which reduces the amount of light passing through but which does not add a colour cast. (ie: it attenuates all wavelengths of light equally)
Neutral density filters are useful for taking photos in bright light using fast film, or for taking longer exposure photos than would be possible otherwise for the film speed in use. A 0.3x filter cuts back one stop of light, a 0.6x filter cuts back two stops, and so on.
cf. colour cast, graduated neutral density filter.
Entry last updated 2002-04-30. Term 831 of 1487.
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