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One of the most important obstacles for the exploration of the night sky is the brightening of the night sky by artificial lights, such as streetlights. The night sky is not really dark in the vicinity of towns or cities, which reduces the visibility of objects beyond the Solar System enourmously.
Depending on the type of celestial object, it is possible to increase the contrast dramatically by blocking the annoying artifical light. This H-beta filter uses a characteristic property of the so called emmission nebulae. Those objekcts glow in special colors, the emmission lines. These emmission lines are linked to chemical elements - in this case hydrogen. A H-beta nebula filter blocks all other colors (and thereby nearly all of the artificial light) and only the emmission line of the hydrogen can pass the filter. The result is astonishing: Suddenly nebulae are visible at locations that were completely empty without a filter. In suburban skies for example the Horsehead Nebula is almost invisible with a 300mm telescope. By using this filter you can see the nebula and its structures without any problems. A must-have for every visual observer!
In contrast to purely visual filters, photographic CCD filters have built-in IR-blocking, which prevents the optical problems caused by infrared radiation.
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!
