Optical filters

device that selectively transmits light of certain wavelengths

filter that passes signals outside a certain frequency range, and attenuates signals within that range

thumb|In the Bohr model of the hydrogen atom, the electron transition from energy level n = 3 to n = 2 results in the emission of an H-alpha photon.

camera accessory consisting of an optical filter

In spectroscopy, absorbance (abbreviated as A) is a logarithmic value which describes the portion of a beam of light which does not pass through a sample. Whilst the name refers to the absorption of light, other interactions of light with a sample (reflection, scattering) may also contribute to attenuation of the beam passing through the sample. The term "internal absorbance" is sometimes used to describe beam attenuation caused by absorption, while "attenuance" or "experimental absorbance" can be used to emphasize that beam attenuation can be caused by other phenomena.

Device in optics that reduces light intensity

wavelength-selective optical filter

material used to color light or correct color

optical filter

an optical mirror made of thin transparent layers with periodically varying refractive index

Color filter that allows a small range of colors to pass

200px|thumb|logo of cokin|right thumb|right|Stacked cases of Cokin filters.

materials that block ultraviolet radiation

telescope accessory used to improve details of viewed objects

optical band-pass filter used in the physical sciences

material that diffuses or scatters light, producing soft light

optical fiters that block near-infrared while passing visible light

labeling system for optical filters

filter allows ultraviolet light to pass

EnChroma are a brand of color corrective lenses designed to address the symptoms of red–green color blindness. Studies have shown that these lenses can alter the appearance of colors, but they do not restore normal color vision, and generally agree that they do not allow the wearer to see "new" colors.