Astroklar Light Pollution Filters against light pollution Astrophotography & Night photography
The Astroklar filters are night light filters made of optical glass and are available here as round filters. The special coating reduces the yellow colour casts - resulting from light pollution - and the dull night sky in night landscape, city and astrophotography. These result from artificial light sources that envelop the surroundings of a large city like a kind of bell or sphere.
Even a city with 25,000 inhabitants is sufficient to artificially brighten the surroundings within a radius of 20 kilometres, making the night sky appear cloudy and low in contrast, or to give night photographs a yellow tinge. The artificial light sources that cause the greatest light pollution are sodium vapour lamps (light wavelengths of around 590 nm) and mercury vapour lamps (light wavelengths of 545 nm and 580 nm). Among other things, these wavelengths block our night light filters and thus enable us to take pictures of starry skies and night shots without yellowing - even in large cities and their surrounding areas.