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 Pro 2'' CLS filter
$ 99.00
Omegon
Filters Nebula/ city light filter 1.25 ''
$ 39.90
Omegon
Filters Light Pollution Filter, 2”
$ 59.00
Omegon
Filters 1.25'' deep sky filter
$ 89.00
Omegon
Filters 1.25'' Clear Sky filter
$ 129.00
Omegon
Filters Pro Nebula CLS Deep Sky Filter 1,25''
$ 69.00
Optolong
Filters L-Pro 2''
Our price:
RRP:
$ 223.00
$ 191.00
Optolong
Filters L-Pro 1.25''
Our price:
RRP:
$ 170.00
$ 138.00
Optolong
Filters Clip Filter for Canon EOS APS-C CLS
Our price:
RRP:
$ 106.00
$ 85.00
Optolong
Filters Filter L-eNhance 1.25
Our price:
RRP:
$ 202.00
$ 187.00
Optolong
Filters Clear Sky Filter 82mm
$ 234.00
Optolong
Filters Clear Sky Filter 77mm
$ 181.00
Optolong
Filters Clip Filter for Canon EOS FF L-Pro
Our price:
RRP:
$ 372.00
$ 254.00
STC
Filters Astro Multispectra Filter 2"
$ 372.00
Chroma
Filters LoGlow Light Pollution 1.25"
$ 540.00
Optolong
Filters Clip Filter for Canon EOS APS-C CLS-CCD
Our price:
RRP:
$ 138.00
$ 103.00
Chroma
Filters LoGlow Light Pollution 2"
$ 940.00
Astronomik
Filters CLS Clip Nikon Z XL
$ 213.00
IDAS
Filters Night Glow Suppression Canon EOS APS-C
Our price:
RRP:
$ 383.00
$ 351.00
Astronomik
Filters CLS CCD 50mm
$ 245.00
Astronomik
Filters CLC Canon EOS clip filter APS-C
$ 138.00
Optolong
Filters L-Ultimate 2"
Our price:
RRP:
$ 426.00
$ 411.00
Optolong
Filters L-Pro Filter 77mm
Our price:
RRP:
$ 383.00
$ 306.00
Astronomik
Filters 2" CLS CCD filter
$ 245.00
Vaonis
Filters CLS Filter for VESPERA
$ 245.00
Explore Scientific
Filters 2" CLS filter
$ 89.00
Astronomik
Filters CLS Canon EOS M Clip filter
$ 149.00
Astronomik
Filters CLS Canon EOS XL Clip
$ 191.00
Optolong
Filters L-Ultimate 1,25"
$ 276.00
Astronomik
Filters CLS CCD EOS clip filter
$ 170.00
Astronomik
Filters CLS CCD XL Clip Canon EOS R
$ 266.00
Astronomik
Filters CLS XL Clip Canon EOS R
$ 213.00
Optolong
Filters L-Quad Enhance 2"
$ 255.00
Optolong
Filters L-Pro Clip Sony Full Frame V2
$ 255.00
Explore Scientific
Filters 1.25" CLS filter
$ 62.00
Astronomik
Filters 1.25" CLS CCD filter
$ 106.00
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.
