CLS filters are broadband filters, which means they allow wide incident light wavelength ranges to pass through. They block light only in selected sections of the spectrum. These blocked sections are chosen in such a way that they coincide with the emissions from artificial light sources. In addition to artificial sources, there are also natural sky brightness phenomena, which are also blocked by CLS filters. Ultimately, the sky background appears darker with a CLS filter. The object being observed stands out more clearly against the background.
Omegon
Filters Nebula/ city light filter 1.25 ''
$ 39.90
Optolong
Filters L-Quad Enhance 2"
$ 231.00
Optolong
Filters L-eNhance 2"
$ 254.00
Omegon
Filters Light Pollution Filter, 2”
$ 49.90
Optolong
Filters L-Pro Filter 77mm
$ 370.00
Omegon
Filters 1.25'' deep sky filter
$ 79.00
Celestron
Filters CLS RASA Origin
$ 393.00
Omegon
Filters Pro 2'' CLS filter
$ 89.00
Optolong
Filters L-eNhance APS-C EOS Clip
$ 277.00
Omegon
Filters Pro Nebula CLS Deep Sky Filter 1,25''
$ 59.00
Optolong
Filters L-Pro Canon EOS R Clip
$ 277.00
Optolong
Filters L-Pro Clip Sony Full Frame V2
$ 312.00
Optolong
Filters L-Ultimate 1,25"
$ 312.00
Optolong
Filters L-eNhance 1.25
$ 208.00
Optolong
Filters L-Pro Clip Nikon Z
$ 266.00
Optolong
Filters Clear Sky Filter 82mm
$ 266.00
Omegon
Filters 1.25'' Clear Sky filter
$ 119.00
Astronomik
Filters 1.25" CLS CCD filter
$ 115.00
Astronomik
Filters CLS Clip Nikon Z XL
$ 231.00
Astronomik
Filters CLC Canon EOS clip filter APS-C
$ 150.00
Optolong
Filters Clear Sky Filter 77mm
$ 231.00
Optolong
Filters L-Pro Clip Sony Full Frame
$ 381.00
Antlia
Filters Quad Band Anti-Light Pollution 2''
RRP:
$ 416.00
Our price:
$ 358.00
Astronomik
Filters 2" CLS CCD filter
$ 266.00
Astronomik
Filters CLS CCD XT Clip Canon EOS R XL
$ 323.00
Astronomik
Filters CLS CCD XT Clip Canon EOS APS-C
$ 208.00
Astronomik
Filters CLS CCD Sony Alpha Clip filter
$ 277.00
Celestron
Filters LPS RASA 800
$ 580.00
Astronomik
Filters CLS Sony Alpha Clip filter
$ 231.00
Astronomik
Filters CLS XL Clip Canon EOS R
$ 231.00
Astronomik
Filters CLS 50mm filter, mounted
$ 196.00
Astronomik
Filters T2 CLS CCD filter
$ 219.00
Astronomik
Filters CLS CCD EOS clip filter
$ 185.00
Astronomik
Filters CLS CCD Clip Nikon XL
$ 277.00
Astronomik
Filters CLS CCD XT Clip Sony alpha 7
$ 323.00
Skywatcher
Filters Light Polution CLS 1.25"
$ 37.90
The figure below illustrates the principle using the example of the NGS1 filter from IDAS. The black transmission curve shows which wavelength ranges the filter allows to pass through. 100% would mean no filter effect at all. The transmission curve also shows which light wavelength ranges are blocked by the filter. These ranges are associated with the emissions from sodium-vapour lamps and other disruptive light sources. The CLS filter filters out this unwanted light.
The CLS filter allows broad ranges to pass through and is therefore also suitable for small optics.
