Astronomik CLS Filter

Astronomik CLS Filter

The Astronomik CLS Filter 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 Filter 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.

Main use

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.

Suitability

• 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

The table gives you a short Overview about the suitability of our filters for various applications: Legend ++ The filter is excellent for this application, the dramatic better image! + The filter is good for this application, the much better image! o The filter is suitable for this application, the slightly better image! - The filter is usable for this application. -- The filter is not suitable for this application. 

Quality Characteristics of Astronomik Filters

• Superior Substrate: Astronomik filters consist of a precision polished substrate on which the actual filter, in the form of very thin (dichroic) interference layers, is applied. Because of these high quality measures Astronomik filters will in no way reduce the performance of your optical system. And contrary to common experience with other manufacturers´ filters, with Astronomik filters stars remain fine needle points of light!
• Coating: Astronomik filters consist of up to 130 layers deposited on top of the completely transparent carrier glass. These layers work as the actual filter and as an antireflective coating.
• Durability: Astronomik filters are completely scratch resistant, and not sensitive to moisture, dew, or high humidity. With others’ filters, after a few years, you start to notice their filter is no longer up to its full capability. Not so with Astronomik filters which maintain their ‘brand new’ transmission specifications year after year. And, because of Astronomik’s extraordinarily resistant coating technology, our filters come with a 10year warranty.

Astronomik filters are highquality accessories for visual observing which will significantly expand your observing opportunities. After many years of use your Astronomik filters will be an accessory which will be ready to give you the same joy you experienced many years earlier when they were new. Now that’s an investment worth making!

Compatible Canon EOS R APS-C cameras

Model	Compatibility
Canon EOS R7
Canon EOS R10
Canon EOS R50
Canon EOS R50 V
Canon EOS R100

Non-compatible Canon lenses

Model	Compatibility
Canon RF 14mm f/1.4 L VCM
Canon RF 28mm F2.8 STM
Canon RF 35mm F1.8 IS Macro STM
Canon RF 85mm F1.2L USM
Canon Extender RF 2x
Canon Extender RF 1.4x

Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Thanks to the high-precision machining of the glas substrate, all Astronomik filters are parfocal. The wedge errors are far below all common tolerances. Therefore, all issues concerning focal distances and the exact alignment of images from each color channel are effectively eliminated.

All Astronomik filters are ideal for modern cameras, including both CMOS- and CCD-based models, ensuring you capture the best possible images with your equipment. Sharpness, contrast, and the absence of any reflections and halos are guaranteed. Even with bright stars in the field of view, nebulae and galaxies will be captured with the finest structures. The Astronomik MFR and MaxFR coatings are designed for optimal performance across a wide range of focal ratios of the optics used.

Every Astronomik filter undergoes a rigorous quality control process before delivery.

Technical Specifications

• 92% transmission at 486nm (H-beta)
• 92% transmission at 496nm (OIII)
• 92% transmission at 501nm (OIII)
• 97% transmission at 656nm (H-alpha)
• Transmission range: 450 to 540nm and above 650nm
• Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)
• Finely polished optical glass, free of any striae, residual stresses, and bubbles
• Extremely scratch-resistant and durable coating
• Completely resistant against high humidity and aging effects
• Parfocal with other Astronomik filters
• Diffraction-limited
• Optimized spectral windows
• Delivered in a high-quality, long-lasting filter box
• Made in Germany

In the Box

CLS filter, at selected size. 

Manual & Warranty

Astronomik 10 year warranty