The Astronomik CLS is a budget filter for visual observation, Black & White photography and CCD photographs of nebulae, galaxies and star clusters with astronomical instruments of any size.
The Astronomik CLS blocks the light of the spectral lines of mercury and sodium-vapor lamps and lets the largest part of the visible light and H-alpha emissions pass. All the important emission lines, as well as the spectral region that the very well dark adapted eye can see, can pass through the filter.
The filters are optimized for use with aperture ratios from 1:3 to 1:15. Transmission losses and chromatic distortions, which are problems with other filters, only appear with Astronomik filters when extremely bright aperture ratios of 1:2 and more are used. The CLS filter is suitable for use with telescopes of all aperture sizes and even works well with binoculars.
The Astronomik CLS Light Pollution Filter is good for use under both dark and urban skies for reducing light pollution made by mercury-vapor lamps. For film photography and modified DLSR use, the CLS filter gives good performance and near perfect color balance. While this filter does perform well with webcam and video equipment under light polluted skies, it is not suitable for planetary use.
- Visual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)
- Visual observation (urban skies): Good, an UHC-E or UHC filter is more suitable
- Film photography: Very good, colour balance is near perfect CCD photography: Good, when used with an additional IR-block-filter
- DSLR photography (original): Good, colour balance shifted but contrast enhanced
- DSLR photography (astro modified): Very good, colour balance is near perfect
- DSLR photography (MC modified): Good, when used with an additional IR-block-filter
- Webcam / Video (Planets): Unsuitable
- Webcam / Video (Deep Sky): Very good, if light pollution is a big problem
Astronomik Visual CLS Light Pollution Filter - Canon EOS Clip Features.
About the Astronomik Clip-Filter System....
The patented Astronomik Clip-Filter System is black anodized aluminum and laser-cut on state-of-the-art modern machines. It can be inserted within seconds directly into the EOS camera body. There are no changes necessary and all lens functions (focus, screen, image stabilization) remain functional!
Almost all Canon system lenses (with the exception of the EF-S series) and all M42 and T2 lens adapters, can be used with the Astronomik Clip-Filter System. The Clip-Filter System also acts as an outstanding dust shield, which prevents the possibility of dust settling on the sensor during long time exposure (The MC-Clear filter does not have a filter effect and only acts as a dust shield.)
Note: For Photographers interested in daylight IR-Photography a "MC-modification" is possible for some cameras. If you are interested in this, please send us a short mail. We will give you more details. The "MC-modification" gives you no advantage for normal astrophotography! If you have a full-frame EOS camera, like the 5D or 6D Mk I, you should buy the Astronomik CLS XL EOS Clip Filter instead.
- 92% transmission at 486nm (H-beta)
- 92% transmission at 496nm (OIII)
- 92% transmission at 501nm (OIII)
- 97% transmission at 656nm (H alpha)
- Pass from 450 to 540nm and beyond 650nm
- Parfocal with other Astronomik filters
- Glass thickness: 1mm
- Completely resistant against high humidity, scratches and aging effects
- Diffraction limited, the filter will not reduce the optical performance of your telescope!
- Astronomik filters are delivered in a high-quality, long lasting, filter box