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A filter is a device that separates a substance trying to flow through it by allowing part
of the substance to be transmitted while selectively inhibiting the transmission of the
rest. Filters are used with liquids to remove solid impurities. Electrical filters restrict the
frequency spectrum of current flowing in a circuit. Optical filters are used to transmit
specific frequencies, uniformly reduce the intensity of a light beam or control the beam’s
polarization.
Filters can be classified into three categories, according to the way they’re used:
- Attenuation filters
- Wavelength-selective filters (both transmissive and reflective)
- Polarization filters
Common examples of colored filters are the filters on colored spotlights for lighting fountains,
buildings and theatrical stages. Examples of attenuation filters are sunglasses and tinted
windows.
Several of the applications of optical filters are in photography, optical communication,
radar systems, holography, and general laser and electro-optical laboratory experiments.
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- Neutral Density Filters
- Tech SpecTM Absorptive
- Tech SpecTM Reflective
- Circular ND Filter & Mount
- Kodak Wratten
- Mounted Absorptive
- Circular Variable
- Mounted IR Filter
- UV
- Mounted Glass UV Filters
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