neutral-density filter


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neutral-density filter

[′nü·trəl ¦den·səd·ē ′fil·tər]
(optics)
An optical filter that reduces the intensity of light without appreciably changing its color; used on a camera when the lens cannot be stopped down sufficiently for use with a given film. Also known as gray filter; neutral filter.
References in periodicals archive ?
Light stimuli were provided by a 150-W quartz halogen lamp and monochromator (CM110, Spectral Products), with stimulus flash irradiance and 75-ms flash duration controlled by a neutral-density filter wheel and electromagnetic shutter (VS25, Uniblitz).
The neutral-density filter rings are attached directly to the objective for easy exchange when brightness adjustment is necessary.
4] plate, a 10% neutral-density filter was placed in the beam incident on the sample for measurements made at -15/15.
Increase the lighting to reduce the sensitivity needed in the camera and add a fixed neutral-density filter.
If you find your CCD camera overexposes the Sun even while using your fastest shutter speed, a neutral-density filter put in front of the camera will reduce incoming light to acceptable levels.
To prevent "Moon blindness" upon looking away from the eyepiece, use a neutral-density filter, or Moon filter.
Instead, we formed the image with a 6-mm achromatic lens of 200-mm focal length and reduced its brightness with a neutral-density filter.
DayStar filters will supply the telescope optical tube assemblies and neutral-density filters for capturing partial phases.
The neutral-density filters were selected to approximately equalize the signal strength produced by the camera at each filter-wheel position when viewing a Kodak[R] n eutral gray reference card.
Both these attributes permit high-light-level, bright-field imaging without the addition of mechanical shutters or neutral-density filters.
Neutral-density filters are handy for extending shutter speeds to several seconds or longer if you wish to record the incoming sea as a misty froth.