A range of filters are available for Astronomy.
Filters are an accessory used in astronomy with telescopes and/or instruments such as a CCD camera, to improve the observation of celestial objects and/or to facilitate the measurement of the number of photons of selected wavelengths of light. Filters of varying wavelength width or bandpass can be used.
A range of filter choices are available depending on the type of observation: for solar, lunar, planetary, stellar and nebula observations. Filter properties and types will change depending on the specific wavelengths or regions of the electromagnetic spectrum observed. Filters are usually made of glass, acrylic or other similar transparent material and then coated as required. Filters can be placed in different locations of the optical path but typically just before the eyepiece lens or detector.
