The UHC (Ultra High Contrast) broadband filter was designed to improve the visibility of various deep-sky objects.

This is achieved in part by reducing the transmission of light pollution wavelengths, particularly those resulting from artificial lighting including mercury vapor lamps. But also by blocking the emissions of sodium vapor lamps and the harmful sky glow effect. Together with the highly transparent transmission lines OIII (496 nm and 500 nm), H-beta (486 nm), NII (654 nm and 658 nm), H-alpha (656 nm) and SII (672 nm) this filter is perfect for improving contrast and details for visual and photographic uses, in areas with strong light pollution.

Performance and main uses

• Suitable for unmodified color CCD and DSLR cameras
• The UHC filter with reduced width of the bandpass range offers greater contrast than the CLS and is therefore more suitable for the city environment, subject to greater air pollution.
• The UHC filter has a notable bandpass range in the red and therefore allows exceptional photographic recordings of objects such as the Orion Nebula (M42)
• Light pollution filters do not increase the brightness of objects and cannot exclusively eliminate the effects of light pollution. In many cases, however, they increase the contrast between the nebula and the night sky.

Quality materials:

• German made branded glass substrate, 1.0mm thickness
• Multi-layer anti-reflection coating, deposited via electron beam evaporation and ion beam assisted deposition

Quality finish:

• Precision optically polished substrate up to 1/4 lambda and <30 arcseconds of parallelism on both sides
• Polish quality 60/40 according to MIL-O-13830 specifications
• Uniform and precise coating method ensuring high passband transmission and precise off-band blocking

Attention, this filter must never be used alone for observing the Sun!

This item is not available for customers in Germany.