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 12nm Astronomik Narrowband-Emissionline filters are optimized for use with system cameras with CMOS sensors. They are also a good choice for CCD cameras with normal or high dark current. The 12nm filters are also the preferred choice for cameras with an integrated or dual guiding sensor, as they show more guiding stars compared to filters with 6nm or 4nm FWHM.

The 12nm filters are the most affordable way to get started with Narrowband-Emissionline filters. Usually, the background signal in images taken from suburban or dark-sky locations is limited by the sensor’s dark current rather than light pollution. Therefore, further suppression of the sky background by reducing the FWHM does not reveal more details of the object.

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.

12nm MFR-coated filters can be used in all instruments with aperture ratios from f/3 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-Filter for Canon EOS APS-C DSLR cameras

Canon EOS DSLR cameras with APS-C sensors are 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.

The Astronomik EOS APS-C Clip-Filters are made from black anodized aluminum.

Additionally, all Astronomik EOS APS-C 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 APS-C Clip-Filter is the right choice.

Use Astronomik filters for your Canon EOS APS-C DSLR camera and enjoy marvelous images with an ultra light equipment!

Compatible Canon EOS APS-C DSLR cameras

Model	Compatibility
Canon EOS-1D (all variants)
Canon EOS 5D (all variants)
Canon EOS 7D
Canon EOS 7D Mark II
Canon EOS 20D
Canon EOS 20Da
Canon EOS 30D
Canon EOS 40D
Canon EOS 50D
Canon EOS 60D
Canon EOS 60Da
Canon EOS 70D
Canon EOS 77D
Canon EOS 80D
Canon EOS 90D
Canon EOS 100D / Rebel SL1 / Kiss X7
Canon EOS 200D / Rebel SL2 / Kiss X9
Canon EOS 250D / Rebel SL3 / Kiss X10
Canon EOS 300D / Digital Rebel / Kiss Digital
Canon EOS 350D / Digital Rebel XT / Kiss Digital N
Canon EOS 400D / Digital Rebel XTi / Kiss Digital X
Canon EOS 450D / Digital Rebel XSi / Kiss X2
Canon EOS 500D / Digital Rebel T1i / Kiss X3
Canon EOS 550D / Digital Rebel T2i / Kiss X4
Canon EOS 600D / Digital Rebel T3i / Kiss X5
Canon EOS 650D / Digital Rebel T4i / Kiss X6i
Canon EOS 700D / Digital Rebel T5i / Kiss X7i
Canon EOS 750D / Rebel T6i / Kiss X8i
Canon EOS 760D / Rebel T6s / 8000D
Canon EOS 800D / Rebel T7i / Kiss X9i
Canon EOS 850D / Rebel T8i / Kiss X10i
Canon EOS 1000D / Digital Rebel XS / Kiss F
Canon EOS 1100D / Rebel T3 / Kiss X50
Canon EOS 1200D / Rebel T5 / Kiss X70
Canon EOS 1300D / Rebel T6 / Kiss X80
Canon EOS 1500D / 2000D / Rebel T7 / Kiss X90
Canon EOS 4000D / Rebel T100 / 3000D
Canon cameras offered before 2003

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 and adapters

Model	Compatibility
Original Canon EF-S series lenses
Lenses from third party manufacturers
M42 lens adapters
T2 lens adapters

Technical Data

• Guaranteed transmission of more than 90% at the H-alpha line (656nm)
• Typical transmission of 96% at the H-alpha line
• Full-Width-Half Maximum (FWHM): 12nm
• 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.