CLS Astronomic Filter designed for Canon EOS cameras.
Astronomik CLS is a budget filter for visual observations, black and white photography and CCD photography of nebulae, galaxies and star clusters, for use with any astronomical instruments.
The CLS filter blocks light from mercury emission lines and sodium vapors, while transmitting the majority of the visible band and the h-? region. The filter passes all the astronomical lines of emission and spectral regions visible to the eye well adapted to the dark.
A filter designed for telescopes of any aperture, starting from the smallest. The filter has been optimized for light between 1: 3 and 1:15. Transmission decays and distortions associated with chromatic aberration can only be manifested in extremely bright systems, with a light intensity of 1: 2.
• visual observations under the dark sky: good to eliminate light pollution from mercury and sodium lamps
• visual observations under the urban sky: good, UHC-E or UHC are more recommended
• photography on film: very good, almost perfect color balance
• CCD photography: good when used with an additional IR filter
• unmodified mirror photography: good, the color balance is shifted, but the contrast is improved
• photography of a reflex camera modified for astrophotography: very good, almost perfect color balance
• webcam / video cameras for planetary photography: not applicable
• webcam / video cameras when photographing nebular objects: very good when light pollution is a big problem
• transmission for the 486 nm (H-beta) line: 92%
• transmission for the 496 nm (O-III) line: 92%
• transmission for the 501 nm (O-III) line: 92%
• transmission for the 656 nm (H-alpha) line: 97%
• transmits 450 to 540 nm and above 650 nm
• transmits almost 100% of the H-beta line
• diffraction-limited accuracy
• parchocal with other Astronomic filters
• thickness: 1 mm
• resistant to moisture, scratch, does not age