In contrast to purely visual filters, photographic CCD filters have built-in IR-blocking, which prevents the optical problems caused by infrared radiation.
Astronomik CLS-CCD Filter
The Astronomik CLS CCD is suitable under light-polluted skies for DSLR Cameras, which have been remodeled for astronomical use. The filter enhances the contrast between all deep-sky objects and the background.
We have re-desgined all of our photographic filters. Since the end of 2008 we are shipping our new "Halo-Free" filters.
The CLS-CCD Filter enhances the contrast between astronomical objects and the background. Due to the wider transmission curve compared to UHC filters, a greater amount of light will pass the filter. Stars will be less dimmed. This filter has been optimized to block as much spurious light as possible and simultaneously provide the best performance for 'useful' light. A good filter for DSLR-, CCD- and film b/w-photography as well as observation of deep-sky-objects with telescopes or photo lenses of all aperture f/3 and above.
The filter blocks completely emission lines of artificial light sources like streetlights (e.g. sodium- and mercury-vapor) as well as the airglow. All 'important' emission lines as well as the spectral range of the night-adapted eye are beeing passed. The supplementary IR-blocking layer allows the use for DSLR- and Webcams without an integrated IR-block filter.
Please note: In principle, all camera lenses can be used with the Clip-Filter - i.e. Canon EF lenses or camera lenses from other third party manufacturers such as Sigma, Tamron, Tokina, Walimex etc. However, the use of clip-filters with Canon EF-S lenses is NOT possible!