The Astronomik H-alpha filter is ideal for imaging HII regions from both light-polluted and dark observation sites.

The Astronomik H-alpha filter significantly enhances the contrast between objects emitting light at 656nm (H-alpha line) and the sky background, allowing for long exposure times for deep and high-contrast images.

The filter blocks the emission lines of high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, the maxima of typical LED lights, most lines of natural airglow, as well as most of the distracting moonlight.

The Astronomik H-alpha filter effectively blocks all unwanted light from wavelengths other than 656nm, from ultraviolet (UV) to infrared (IR).

The Astronomik H-alpha filter MUST NOT BE USED for solar observation!

Difference between Astronomik 12nm, 6nm and 4nm filters

The choice between 12nm, 6nm and 4nm Full-Width-Half-Maximum (FWHM) filters depends on your imaging conditions and camera type. There is no universal “best” option - each FWHM serves a specific purpose.

The 6nm Astronomik Narrowband-Emissionline filters are usually the best choice for astrophotography. They are ideal for imaging faint objects in star-crowded regions of the milky way, as they typically halve the number of stars in the image compared to 12nm filters, greatly simplifying image processing.

The 6nm Narrowband-Emissionline filters are the first choice, especially if you are using a CMOS astro camera or a modern system camera with very low dark current, or if you are observing from a location with strong light pollution. The excellent suppression of the sky background allows you to use long exposure times. The 6nm filters provide a dark background and outstanding details of faint nebulae.

The Astronomik MFR coating

Both the Astronomik MFR and MaxFR coatings offer extremely high contrast, minimized stray light, no halos and needle-sharp stars. In addition, they provide the best possible blocking across the entire spectral range from UV to IR.

6nm MFR-coated filters can be used in all instruments with aperture ratios from f/4 to f/15 without visible performance loss.

Astronomik XT-Filters

The new Astronomik XT-Filters are specifically designed for astrophotography with wide-angle lenses, delivering sharp and crisp star images all the way to the edges of the image.

Since many years, Astronomik Clip-Filters are a popular and well known tool among astrophotographers worldwide. However, when using very short focal length lenses to take widefield images, standard Clip-Filters could introduce aberrations, stretching stars in the outermost corners of the image. To solve this issue, the new Astronomik XT-Filters are coated on an extremely thin substrate of only 0.3mm or 0,5mm thickness, significantly reducing these aberrations.

Despite the reduced thickness, the Astronomik XT-Filters maintain the highest optical quality: they are finely polished, free of any striae, residual stresses, and bubbles, and are suitable for the most advanced imaging applications.

The Astronomik XT-Filters are manufactured using the same durable coating technology as all Astronomik filters. They are extremely scratch-resistant, unaffected by high humidity, and do not degrade over time. This ensures they retain their performance for years. As with all our filters, we underline this promise with a 10-year warranty.

Please note that not all Astronomik filters are available as XT-versions due to the complexity of manufacturing these ultra-thin filters. Currently, filters are produced that are predestined for photography with wide-angle lenses.

Clip-Filters for mirrorless Canon EOS M cameras

The compact mirrorless Canon EOS M series is an excellent choice for astrophotography. With Astronomik Clip-Filters, you can use our full range of filters with your camera to capture stunning images. Whether paired with a camera lens or a telescope, our Clip-Filters ensure maximum image quality and performance from your setup.

The Astronomik Clip-Filters offer a number of practical advantages that make them an ideal choice for astrophotographers:

• Installing and removing the Astronomik Clip-Filter is very quick and easy and requires no extra tools or modifications to the camera body. They can be changed at any time, even at night.
• All lens functions, such as focus, aperture, and image stabilization remain fully functional.
• The Astronomik Clip-Filters are held securely in place without stressing the high-quality glass.
• The Astronomik Clip-Filters are designed and optimized for use with both standard camera lenses and telescopes.

Through the Astronomik Clip-Filters, we were able to solve several common issues faced by astrophotographers:

• Large filters for large camera lenses are very expensive.
• Using a filter holder between the camera body and the lens prevents focusing to infinity.
• For very fast telescopes (low f-number) like the Vixen R200SS or the Takahashi “Epsilon” astrograph, a filter drawer or filter wheel can not be used because the distance to the corrector lenses would be changed.
• Long exposure times lead to dust settling on the camera’s sensor chip.

Additionally, all Astronomik EOS M Clip-Filters serve as an excellent dust shield, protecting the sensor during long exposures. If you only need a dust shield without filtering effects, the Astronomik MC-Clear EOS M Clip-Filter is the right choice.

NOTE: Please store the Clip-Filter in the supplied storage box and do not leave it in the camera permanently.

Use Astronomik filters for your Canon EOS M camera and enjoy marvelous images with an ultra light equipment!

Compatible Canon EOS M cameras

Model	Compatibility
Canon EOS M
Canon EOS M2
Canon EOS M3
Canon EOS M5
Canon EOS M6
Canon EOS M6 Mark II
Canon EOS M10
Canon EOS M50 / Kiss M
Canon EOS M50 Mark II / Kiss M2
Canon EOS M100
Canon EOS M200

The Astronomik EOS APS-C Clip-Filters fit into the original Canon EF to EF-M bayonet adapter and can be used with all variants of the Canon EOS M camera.

Compatible lenses

Model	Compatibility
Lenses with EF-M bayonet
Lenses with EF-S or EF bayonet (with Canon EF-M to EF/EF-S adapter)
Lenses from other manufacturers with Canon bayonet

Technical Data

• Guaranteed transmission of more than 90% at the H-alpha line (656nm)
• Typical transmission of 93% at the H-alpha line
• Full-Width-Half Maximum (FWHM): 6nm
• 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
• Astronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)
• Parfocal with other Astronomik filters
• Diffraction-limited
• Optimized spectral windows
• Delivered in a high-quality, long-lasting filter box
• Made in Germany

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. Additionally, each Astronomik Narrowband-Emissionline filter is measured using a high-end PerkinElmer Spectrophotometer to ensure it meets the specifications published on our website. On the back of each Narrowband-Emissionline filter box, you will find a label detailing the precise spectral data for that specific filter, including the maximum transmission and the recommended range of focal ratios for best performance of that specific filter.