A real gain in polluted environments

The CLS CCD is suitable under light polluted skies for ASTRO defiltered then refiltered DSLR cameras. The filter improves the contrast between all deep sky objects and the background.

The CLS-CCD filter improves the contrast between astronomical objects and the background. Due to the wider transmission curve compared to UHC filters, more light will pass the filter. The stars will be less dim. This filter has been optimized to block as much stray light as possible and simultaneously provide the best performance for “useful” light. A good filter for black-and-white photography with DSLR, CCD, and film, as well as for observing deep-sky objects with telescopes or camera lenses of all f/2 apertures and above.

Main use

The filter completely blocks the emission lines of artificial light sources such as street lamps (eg sodium and mercury vapor) as well as air glow. All “important” emission lines as well as the spectral range of the night-adapted eye are exceeded. The additional IR blocking layer allows the use of DSLRs and webcams without an integrated IR block filter.
Other uses

• Easier resolution of double stars.
• With the EOS-Clip model, photography with DSLR cameras is possible even in extreme light pollution conditions without changing the white balance.
• The 1.25" and 2" socket models can be used for observations from light polluted areas.
• If you plan to create color images from emission line data, our CLS-CCD filter is an excellent choice for the luminance channel

Information

• Visual observation (dark sky): good, to reduce light pollution from mercury vapor lamps (public lighting)
• Visual observation (urban sky): Reasonable, a UHC-E or UHC filter is more suitable
• Film photography: very good, the color balance is almost perfect
• CCD photography: very good, optimized rejection of light pollution
• DSLR photography (original): good, color balance shifted but contrast improved
• DSLR photography (astro modified): Very good, the color balance is almost perfect
• DSLR photography (MC modified): Very good, color balance is almost perfect
• Webcam / video (planets): not suitable
• Webcam / Video (Deep Sky): Very good, if light pollution is a big problem

Technical data

• 95% transmission at 486 nm (H-beta)
• 95% transmission at 496 nm (OIII)
• 95% transmission at 501 nm (OIII)
• 97% transmission at 656 nm (H-alpha)
• switch from 450 to 520nm and from 640 to 690nm
• Parfocal with other Astronomik filters
• Glass thickness: 1mm
• Fully resistant to high humidity, scratches and the effects of aging
• Diffraction limited, the filter will not reduce the optical performance of your telescope!
• Astronomik filters come in a high quality, durable filter housing