The Astronomik CLS is our inexpensive sollution for the visual deep-sky observation, b&w photography and CCD observation.
The Astronomik CLS filter is the right filter to gain the contrast of nearly all objects under light-polluted skies with all sizes of telescopes. Due to the design of the transmission curve the filter reduces the sky background and gas nebulas, planetary nebulas as well as open clusters, globular clusters and galaxies are seen better. The Astronomik CLS blocks the emission of Hg and Na streetlights as well as all Skyglow-lines . All major emission lines from deep-sky objects are passed without surpression. As you can see from the chart below the most important part of the eye´s night-sesitive region is passed with maximum transmission.
The filter are optimised for the use with focal ratio from 1:4 to 1:15. Loss of transmission and colour displacements, that appear at other filters, emerge with the Astronomik filters only at extreme fast focal ratios of 1:2 and bigger.
Compared to the "Deep-Sky" filters sold by other manufacturers the Astronomik CLS shows you more stars and more details in the nebulas. Because of the high quality of the glas you will see stars as the small pinpoints you know from your scope.
The Astronomik CLS can be used with all sizes of instruments. Even the use in front of binoculars is a great improvement.
The red lines are the most important lines from artificial light pollution. The green lines are the most prominent emission lines for nebulas. The grey curve is the human eye´s night-sensitivity. The blue line is the transmission curve of the filter.
High transmission of nearly 100% between 450nm and 530nm.
Transmission of ca 96% at H-alpha.
Total blocking of all unwanted light from light-pollution.
The ideal allround filter for deep-sky observing, even with small scopes.
Completly resistant against high humidity and scratches.
Highest optical quality on the market.
Please, ask for availability before placing your order. Thank you in advance.