A glass filter that attenuates light evenly over the visible spectrum. It would be used to reduce the amount of light entering a lens and thus force the iris open to its maximum. This is to simulate conditions of low light in order to set the focus accurately on the desired part of the scene, for low light operation.
a gray (colorless) filter that will cut some of the light out
a simply a filter which reduces the brightness of light entering the lens (without affecting color balance - hence 'neutral')
A filter placed between the laser beam and the desired object under test to reduce the optical power by a pre-determined percentage.
Abbreviation for Neutral Density Filter. Attached to the front of the camera's lens, it reduces the amount of light entering the lens. When light levels are strong, such as when outdoors in sunshine, attaching an ND filter allows you to use both your maximum aperture and slower shutter speeds.
Neutral density filter: Lens filter that helps prevent overexposure. Prosumer camcorders have built-in ND filters.
Short for neutral density filter; used to reduce the amount of light passing through a lens without altering the image's color or tonal rendition.
A filter that attenuates light evenly over the visible light spectrum. It reduces the light entering a lens, thus forcing the iris to open to its maximum.
When capturing a scene under bright sunshine, the iris may overcompensate by contracting too much, resulting in loss of focus. The ND Filter prevents this by restricting the amount of light entering the iris. Two settings, ND1 (1/4 of total light amount) and ND2 (1/32 of total light amount), are available to allow perfect recording under harsh lighting conditions.
