In astronomy, optical Filters are used with telescopes to limit the spectrum reaching a sensor, by which an image over a more-limited range of Electromagnetic Radiation can be produced. They are used for Visible Light and adjacent regions of the EMR spectrum (within the Infrared and Ultraviolet Bands).
The term Passband can be thought of as the specification of such a filter, but the two terms are often treated almost as synonyms, and often the letter identifying the band is used to refer to the filter or to the Intensity of an object (star) seen through the filter.
Filters are also used for higher energy EMR, e.g., X-rays.
Exoplanet Eclipse Light Curve
JHK Photometric System (JHK)
Lyman-Break Galaxy (LBG)
Palomar Four-Filter Survey (PC)
Sensitivity Function (S)
Sloan 2.5m Telescope
SkyMapper Southern Survey (SMSS)
Strömgren Photometric System
UK Schmidt Survey