The Astronomik H-alpha filter is a narrow band filter for CCD photography. The filter lets the H-alpha light of emission nebulae pass and blocks nearly the whole remainder of the spectrum where the CCD is sensitive.

The full width at half-maximum (FWHM) of 12nm is optimized for the use with common CCD cameras and allows the use of very fast optics. It should be noted that the filter has a transmission of up to 99%.Another advantage of the 12nm filters is the availability of guiding stars for cameras with a built-in-autoguider (SBIG). If you use a very strong filter like our 6nm filter you often won’t find a usable guidestar.The range of application extends from 1:2.8 to 1:15. Transmission losses and chromatic distortions, which arise with other filters, only occur with Astronomik filters when extremely bright aperture ratios of 1:2 and more come into play.

Main use

The Astronomik H-alpha-CCD (12nm version) increases the contrast between objects, in this case between the H-alpha emission line and the skyglow background. Our Astronomik H-alpha-CCD (12nm version) completely suppresses the emission lines of artificial lighting (mercury (Hg) and sodium (Na)) and skyglow.

Other uses

• When using the OIII CCD and the SII-CCD filters you can obtain three-color images of emission line objects (gas nebulae) from locations with very strong light pollution. To do so, you would take an image in three different wavelengths, select each one as a color-channel in Photoshop and paste them together as a color image.
• The Astronomik H-Alpha filters may NOT be used for solar observation.
• If you plan to create color images from emission line data, our CLS-CCD filter is a great choice for the Luminance channel.

Suitability

• Visual observation (dark skies): Unsuitable
• Visual observation (urban skies): Unsuitable
• Film photography: Reasonable, but very long exposure times
• CCD photography: Very good, huge contrast enhancement at H II-emission nebulas
• DSLR photography (original): Good, reduced sensitivity in the H-alpha band
• DSLR photography (astro modified): Very good, huge contrast enhancement at H II-emission nebulas
• DSLR photography (MC modified): Very good, huge contrast enhancement at H II-emission nebulas
• Webcam / Video (Planets): Unsuitable
• Webcam / Video (Deep Sky): Good, good contrast enhancement with bright objects

Technical Data

• typ. transmission of more then 95% at the H-alpha line (656nm)
• Complete blocking from all disturbing wavelengths in the infrared
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

Astronomik now offers you a range of three different UV+IR blockers as Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera.

The Luminance channel is probably the most important for a great final image! You want as much signal as possible so the filter should have the highest transmission possible with a wide spectral bandpass. This combination provides the greatest sensitivity and gives you the highest photon counts on your pixels. While the high transmission level is a great aspect of the new Astronomik Luminance filters, not all optical instruments or additional optical elements like correctors, field-flatteners or reducers, have perfect colour correction so it can be the width of the spectral band pass of  the Luminance filter that can cause problems. A band pass that is too wide will allow the transmission of incompletely focused light (Chromatic aberration), making stars appear soft or bloated. In such cases image processing can become difficult, so having a slightly narrowed spectral window in your Luminance filter can reduce or eliminate this damaging effect.

To give you all the tools to gather the best data possible we have expanded our line of Luminance filters: Now you can select a Luminance filter perfectly matched to the kind of telescope you use, to get the highest signal and sharpest image for the Luminance channel!
Depending on the color correction of your scope you may use a wider spectral window for the Luminance data. The L1 filter has the widest spectral window, the L2 is about the same as our current L-Filter and the L3 is much narrower.
If you use an optical system that is completely free of any chromatic aberration you should get an L1 filter for your setup. For general use the L2 filter is well suited to most optical systems with a corrector, flattener or reducer in the optical train while the L3 filter is designed for users of refractors with a less-than-perfect color correction and in combination with the new Deep-Sky RGB filters, the L3 filter will minimise the problem of bluish halos around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Additional note for observers working under light polluted skies:
If your observing site suffers from light pollution you should try to use our CLS-CCD as a replacement for the Luminance filter. The transmission curve of the CLS-CCD will give you approximately the same amount of energy in all three colour channels while blocking nearly all unwanted artifical light pollution. Customers who replaced the Lx filter with the CLS-CCD are amazed by the increased quality of their data. This small change gives you the opportunity to take much deeper images from your current observing site.

Astronomik now offers you a range of three different UV+IR blockers as Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera.

The Luminance channel is probably the most important for a great final image! You want as much signal as possible so the filter should have the highest transmission possible with a wide spectral bandpass. This combination provides the greatest sensitivity and gives you the highest photon counts on your pixels. While the high transmission level is a great aspect of the new Astronomik Luminance filters, not all optical instruments or additional optical elements like correctors, field-flatteners or reducers, have perfect colour correction so it can be the width of the spectral band pass of  the Luminance filter that can cause problems. A band pass that is too wide will allow the transmission of incompletely focused light (Chromatic aberration), making stars appear soft or bloated. In such cases image processing can become difficult, so having a slightly narrowed spectral window in your Luminance filter can reduce or eliminate this damaging effect.

To give you all the tools to gather the best data possible we have expanded our line of Luminance filters: Now you can select a Luminance filter perfectly matched to the kind of telescope you use, to get the highest signal and sharpest image for the Luminance channel!
Depending on the color correction of your scope you may use a wider spectral window for the Luminance data. The L1 filter has the widest spectral window, the L2 is about the same as our current L-Filter and the L3 is much narrower.
If you use an optical system that is completely free of any chromatic aberration you should get an L1 filter for your setup. For general use the L2 filter is well suited to most optical systems with a corrector, flattener or reducer in the optical train while the L3 filter is designed for users of refractors with a less-than-perfect color correction and in combination with the new Deep-Sky RGB filters, the L3 filter will minimise the problem of bluish halos around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Additional note for observers working under light polluted skies:
If your observing site suffers from light pollution you should try to use our CLS-CCD as a replacement for the Luminance filter. The transmission curve of the CLS-CCD will give you approximately the same amount of energy in all three colour channels while blocking nearly all unwanted artifical light pollution. Customers who replaced the Lx filter with the CLS-CCD are amazed by the increased quality of their data. This small change gives you the opportunity to take much deeper images from your current observing site.

The Astronomik ProPlanet 642 BP is the lastest addition to the family of Astromik ProPlanet IR-pass filters. The filter thrills because of it´s wide range of applikations for daylight IR-Photography, high-resolution lunar and planetary imaging and for taking beautifull and deep images of H-alpha regions when used for Astrophotography.

What does BP stand for ?

"BP" are short for "Bandpass": The filter gives you a 200nm spectral window from 642nm to 842nm. Contrary to the other two ProPlanet filters it blocks the longer infrared. Together with the Astronmik ProPlanet 742 and the ProPlanet 807 you can now have three choices to match your needs when imaging in the IR. The Astronomik ProPlanet 642 BP will be the right choice for the best image quite often!

The Astronomik ProPlanet 642 BP will give you three filters in one single product! Depending on your camera, the Astronomik ProPlanet 642 BP is a great tool either for daylight IR-imaging with your digital camera, or it will reduce seeing effects and enhance contrast when used for lunar- and planetary imaging, and third it will be a very good and low-priced H-alpha Filter for getting started in Deep-Sky Astrophotography of H-alpha regions.
Due to our skillfull developement with lot´s of tests we reached the goal to give you a filter which will do a perfect job to deliver amazing images.

Daylight IR-imaging:

• contrasty images with a great rendition of colors
• Clear "Wood-Effect" images
• Not Hot-Spot from longer IR!
• Short exposure times, about the same as normal VIS-imaging
• perfect choice for Infrared-Videos

High-resolution Lunar and planetary imaging:

• short Exposure times
• effective reduction of Seeing
• enhanced contrast
• no ghosts and best sharpness due to blocking the longer IR

Deep-Sky Astrophotography of HII regions:

• best transmission of the H-alpha line at 656nm
• about 40nm FWHM with astro-modified DSLRs
• amazing contrast under lightpolluted skies or moonlight
• low priced filter for getting started in H-alpha imaging
• easy focussing using camera display plus LiveView!

Guiding for Astrophotography:

• installing the 642BP in front of your autoguider-camera dramatically improves guiding quality, as image-motion from one frame to the next is minimized.

Technical Data

• more then 96% transmission for wavelengths of 642nm to 840nm
• blocking of wavelengths between 350nm and 630nm
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

The new Astronomik Deep-Sky RGB filters are the result of a long and detailed process of research and development. We have created the most advanced set of RGB filters for Deep-Sky imaging available today.
The transmission curves of the three filters are designed to give you strong and vivid colors with a strong reinforcement of the most important emission lines. Data taken with the new Astronomik Deep-Sky RGB filters is easier to process into a beautiful final masterpiece.

Feedback from our test-users and the first customers is really exciting. All of them reported smaller, sharper stars and this was one of our design goals, so these filters are designed to give you the best contrast and the smallest stars possible!

During the design of the Deep-Sky RGB filters we took a close look at the sensitivity curves of today’s popular CCD cameras. The result was we found a way to make one set of filters for all kind of sensors ranging from KAF- and KAI-sensors, to the chips made by Sony, meaning you can do 1:1:1 ratio RGB exposures with all sensors, with only minimal tweaking necessary during processing to achieve perfect colours in your image!

The transmission curve characteristics and coatings on the new Deep Sky RGB filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies

Additional to the Deep-Sky RGB filters Astronomik now offers you three different Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera, even with instruments with less-than-perfect colour correction. (Link einfügen)

Like all Astronomik Filters, the new Deep-Sky RGB filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Astronomik Deep-Sky RGB Key features:

• Maximum transmission of up to 95%
• Ultra-Sharp, pinpoint star images
• High contrast
• Easy to process data for vivid colours in the final image
• Optimized spectral windows for max photon counts on the sensor
• Made on finest, opticaly polished glass
• Extremly durable, scratch resistant coating
• MFR Coating technique for a wide range of focal ratios

Astronomik now offers you a range of three different UV+IR blockers as Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera.

The Luminance channel is probably the most important for a great final image! You want as much signal as possible so the filter should have the highest transmission possible with a wide spectral bandpass. This combination provides the greatest sensitivity and gives you the highest photon counts on your pixels. While the high transmission level is a great aspect of the new Astronomik Luminance filters, not all optical instruments or additional optical elements like correctors, field-flatteners or reducers, have perfect colour correction so it can be the width of the spectral band pass of  the Luminance filter that can cause problems. A band pass that is too wide will allow the transmission of incompletely focused light (Chromatic aberration), making stars appear soft or bloated. In such cases image processing can become difficult, so having a slightly narrowed spectral window in your Luminance filter can reduce or eliminate this damaging effect.

To give you all the tools to gather the best data possible we have expanded our line of Luminance filters: Now you can select a Luminance filter perfectly matched to the kind of telescope you use, to get the highest signal and sharpest image for the Luminance channel!
Depending on the color correction of your scope you may use a wider spectral window for the Luminance data. The L1 filter has the widest spectral window, the L2 is about the same as our current L-Filter and the L3 is much narrower.
If you use an optical system that is completely free of any chromatic aberration you should get an L1 filter for your setup. For general use the L2 filter is well suited to most optical systems with a corrector, flattener or reducer in the optical train while the L3 filter is designed for users of refractors with a less-than-perfect color correction and in combination with the new Deep-Sky RGB filters, the L3 filter will minimise the problem of bluish halos around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Additional note for observers working under light polluted skies:
If your observing site suffers from light pollution you should try to use our CLS-CCD as a replacement for the Luminance filter. The transmission curve of the CLS-CCD will give you approximately the same amount of energy in all three colour channels while blocking nearly all unwanted artifical light pollution. Customers who replaced the Lx filter with the CLS-CCD are amazed by the increased quality of their data. This small change gives you the opportunity to take much deeper images from your current observing site.

The Astronomik CLS CCD is suitable under light-polluted skies for DSLR Cameras, which have been remodeled for astronomical use. The filter enhances the contrast between all deep-sky objects and the background. 

The CLS-CCD Filter enhances the contrast between astronomical objects and the background. Due to the wider transmission curve compared to UHC filters, a greater amount of light will pass the filter. Stars will be less dimmed. This filter has been optimized to block as much spurious light as possible and simultaneously provide the best performance for 'useful' light. A good filter for DSLR-, CCD- and film b/w-photography as well as observation of deep-sky-objects with telescopes or photo lenses of all aperture f/2 and above.

Main use

The filter blocks completely emission lines of artificial light sources like streetlights (e.g. sodium- and mercury-vapor) as well as the airglow. All 'important' emission lines as well as the spectral range of the night-adapted eye are beeing passed. The supplementary IR-blocking layer allows the use for DSLR- and Webcams without an integrated IR-block filter.

Other uses

• Easier resolution of Double Stars.
• With the EOS-Clip model, photography with DSLR cameras is feasible even unter extreme light-polluting conditions without shifting the white balance.
• The 1,25" and 2" socket models can be used for observations from light-polluted areas.
• If you plan to create color images from emission line data, our CLS-CCD filter is a great choice for the Luminance channel

Alternatives

CLS: For cameras with an integrated IR-filter or for visual observation.

Suitability

• Visual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)
• Visual observation (urban skies): Reasonable, an UHC-E or UHC filter is more suitable
• Film photography: Very good, colour balance is near perfect
• CCD photography: Very good, optimized rejection of light pollution
• 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): Very good, colour balance is near perfect
• Webcam / Video (Planets): Unsuitable
• Webcam / Video (Deep Sky): Very good, if light pollution is a big problem

Technical Data

• 95% transmission at 486nm (H-beta)
• 95% transmission at 496nm (OIII)
• 95% transmission at 501nm (OIII)
• 97% transmission at 656nm (H-alpha)
• pass from 450 to 520nm and from 640 to 690nm
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

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.

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

Technical Data

• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

All  Astronomik Filters are perfect for modern cameras, including both CMOS and CCD based cameras, allowing you to capture the very best images possible with your instruments. Sharpness, contrast and the absence of any reflections is guaranteed.

Each and every Astronomik filter has to pass a complex quality control process before being suitable for delivery to our customers. Each and every emission line filter is measured with a high-end Perkin-Elmer spectral-photometer to make sure that every single filter is up to the specifications published on our website.

On the back of each filter-box you will find a label that details the precise sensitivity and band pass measurements for that individual filter inside the box: You will see the max transmission and the recommended range of focal ratio were the filter will give you the best performance.

Thus Astronomik OIII CCD filter is a narrow band emission-line-filter for CCD photography. The filter lets the light of double ionized Oxygen of emission nebulae pass and blocks nearly the whole remainder of the spectrum where the CCD is sensitive.

The full width at half maximum (FWHM) of 12 nm is optimal suitable for common CCD cameras and allows the use of very fast optics The optimal aperture ratio for the use of the filter is 1:3 to 1:15 with apertures of more than 6" (150mm). It should be noted that the filter has a transmission of up to 99%, which cannot be attained by stacking more narrow-band filters. A further note, which led to selecting the half width (FWHM), is the dark current of common CCD imagers. Exposures with a CCD cooled to -15°C are limited by the dark current of the CCD, even in large cities with a bright background.

Another advantage of the 12 nm filter is the better availability of guiding stars for cameras with a built-in-autoguider (SBIG). If you use a very strong filter like our H-alpha 6nm filter you often won’t find a usable guidestar.

Together with our other three Astronomik emission-line filters you can do great color images even from very light polluted places!

Main use

The Astronomik OIII CCD increases the contrast between objects, in this case between the OIII emission line and the skyglow background. Our Astronomik OIII CCD completely suppresses the emission lines of artificial lighting (mercury (Hg) and sodium (Na)) and skyglow. Transmission losses and chromatic distortions, which arise with other filters, only occur with Astronomik filters when extremely bright aperture ratios of 1:2 and more come into play. The filter has a built-in IR-blocker up to 1150nm. You don’t need an additional IR-blocker with this filter.

Other uses

• When using the Astronomik OIII CCD filter togther with the H-alpha, OIII CCD and the SII CCD filters you can obtain three-color images of emission line objects (gas nebulae) from locations with very strong light pollution. To do so, you would take an image in three different wavelengths, select each one as a color-channel in Photoshop and paste them together as one single color image.
• If you plan to create color images from emission line data, our CLS CCD filter is a great choice for the Luminance channel
• The OIII CCD is also great for visual observation. If you plan to get filters for visual observation and for astrophotography get the CCD filter: You may use this filter visual as well as in front of you camera. The built-in IR-blocker doesn’t disturb visual observation but you need an additional IR-blocker if you want to use the visual filter with your camera.

Suitability

• Visual observation (dark skies): Very good, huge contrast enhancement at O III-emission nebulas
• Visual observation (urban skies): Very good, huge contrast enhancement at O III-emission nebulas
• Film photography: It depends, very long exposure time
• CCD photography: Very good, huge contrast enhancement at O III-emission nebulas
• DSLR photography (original): Very good, huge contrast enhancement at O III-emission nebulas
• DSLR photography (astro modified): Very good, huge contrast enhancement at O III-emission nebulas
• DSLR photography (MC modified): Very good, huge contrast enhancement at O III-emission nebulas
• Webcam / Video (Planets): Unsuitable
• Webcam / Video (Deep Sky): Reasonable, if light pollution is a big problem and OIII Objects are beeing observed

Technical Data

• typ. 95% transmission at 496nm (OIII)
• typ. 95% transmission at 501nm (OIII)
• full width at half maximum 12nm
• transmission from 494nm to 506nm
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

Ideal addition to the Astronomik ProPlanet IR 742 for imaging the moon and planets, with telescopes larger then 10" (250mm) when the seeing is poor.

This filter is an ideal complement to the ProPlanet IR 742 for use with converted DSLR cameras, CCD cameras and Webcams. The effects of seeing are distinctly reduced. It is your entry into previously unknown dimensions of photography of the moon and the planets.

The ProPlanet IR 807 only allows infrared light with wavelengths of more than 807 nm to pass. In this wavelength range the effects of seeing are significantly lower than in the visible spectrum of the human eye. This allows much sharper images than are usually obtained from your device and location. Another advantage is that the sky background of advanced dawn is dark and even allows photography of planets and moon at daylight.

Main use

The Astronomik ProPlanet IR 807 cuts off the visible part of the spectrum and allows the light of wavelengths longer then 807nm to pass. Due to this behavior the part of the spectrum that is most sensitive to bad seeing is rejected. This approach does a big improvement to the imaging of planets and the moon. The image is more steady than the image in the visible light.

Other uses

• The Astronomik ProPlanet IR 807 is designed to be an addition to the Astronomik ProPlanet IR 742, if the seeing is extremely bad and a larger telescope is used.
• For most cameras the exposure times doubles, compared to the Astronomik ProPlanet IR 742 or imaging in visible light, if the Astronomik ProPlanet IR 807 is used.
• Darkens the background during twilight.
• Imaging of bright planets, stars and comets by day.
• Imaging of young stars in dust clouds and stellar nurseries.

Alternatives

If the seeing is not so bad or if the telescope is smaller than 10" (250mm) we recommend the use of the Astronomik ProPlanet IR 742.

Suitability

• Visual observation (dark skies): Unsuitable, the eye is insensitive at this spectrum
• Visual observation (urban skies): Unsuitable, the eye is insensitive at this spectrum
• Film photography: Unsuitable
• CCD photography: Reasonable, for special IR photography (as chlorophyll)
• DSLR photography (original): Unsuitable
• DSLR photography (astro modified): Unsuitable
• DSLR photography (MC modified): Good, for IR daylight photography, longer exposure time
• Webcam / Video (Planets): Very good, rejects problems with seeing, particularly with telescopes larger 250 mm aperture
• Webcam / Video (Deep Sky): Very good, rejects problems with seeing, particularly with telescopes larger 250 mm aperture

Technical Data

• more then 97% transmission for wavelengths of 807nm to 1100nm
• blocking of wavelengths between 350nm and 790nm
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

The Astronomik 6nm H-alpha filter is an extremely narrow emission-line filter for CCD photography. The filter lets the H-alpha light of emission nebulae pass and blocks nearly the whole remainder of the spectrum where the CCD is sensitive. 

The full width at half-maximum (FWHM) of 6nm is optimized for a maximum contrast between the (H-alpha emitting) object and the background. The contrast gain is much higher than with our 12nm emission line filters but you won’t see as much stars in the resulting images.

The design of the transmission curve makes it possible to use the filters with instruments from 1:3.75 to 1:15. Selected filters for faster system are available upon special request.

All transmission curves of the 6nm filter are measured individually. Because of this procedure you can get the optimum filter for your telescope: If you place a direct order please specify the focal ratio of your instrument and we will select the best filter for your setup. So you may get the best filter without paying for an A+ filter.

Main use

The Astronomik H-alpha-CCD (6nm version) increases the contrast between objects, in this case between the H-alpha emission line and the skyglow background in the same way as the 12nm version. The gain in contrast is much higher due to the smaller FWHM. The 6nm H-Alpha filter is the right choice for extremely dim objects, even in the milkyway, and for observations from heavily light-polluted places. The Astronomik 6nm H-alpha-CCD completely suppresses the emission lines of artificial lighting (mercury (Hg) and sodium (Na)) and skyglow. Transmission losses and chromatic distortions, which arise with other filters, only occur with Astronomik filters when extremely bright aperture ratios come into play. Selected filters for faster systems are available upon special request.

Other uses

• Using the Astronomik 6nm H-Alpha together with the 12nm H-Alpha gives you the ability to have a maximum contrast in the HII objects and to keep the stars in the final image.
• The Astronomik 6nm H-Alpha filter may NOT be used for solar observation.

Suitability

• Visual observation (dark skies): Unsuitable
• Visual observation (urban skies): Unsuitable
• Film photography: Unsuitable
• CCD photography: Very good, huge contrast enhancement at H II-emission nebulas
• DSLR photography (original): Good, reduced sensitivity in the H-alpha band
• DSLR photography (astro modified): Very good, huge contrast enhancement at H II-emission nebulas
• DSLR photography (MC modified): Very good, huge contrast enhancement at H II-emission nebulas
• Webcam / Video (Planets): Unsuitable
• Webcam / Video (Deep Sky): Unsuitable

Technical Data

• typ. transmission von über 90% at H-Alpha (656nm)
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

The Astronomik SII-CCD filter is a narrow-band-filter for CCD photography.The filter lets the light of the ionized sulfur (SII) pass, and blocks nearly the whole remainder of the visual spectrum as well as IR, in which the CCD is sensitive.

The full width at half maximum (FWHM) of 12nm is optimal suitable for common CCD cameras and allows the use of very fast optics. The range of application extends from 1:2.8 to 1:15. Transmission losses and chromatic distortions, which arise with other filters, only occur with Astronomik filters when extremely bright aperture ratios of 1:2 and more come into play. It should be noted, that the filter has a transmission of up to 99%.

Another advantage of the 12nm filters is the good availability of guiding stars for cameras with a built-in-autoguider (SBIG). If you use a very strong filter like our 6nm filter you often won't find a usable guidestar.

The Astronomik SII CCD filter increases the contrast between objects, in this case between those with SII emission lines and the skyglow background. Also, our Astronomik SII-CCD filter completely suppresses the emission lines of artificial lighting (mercury (Hg) and sodium (Na)) and skyglow.

Main use

The Astronomik SII CCD increases the contrast between objects, in this case between the SII emission line and the skyglow background. Our Astronomik SII CCD completely suppresses the emission lines of artificial lighting (mercury (Hg) and sodium (Na)) and skyglow. Due to the high optical quality of the Astronomik H-alpha-CCD substrate you will see the same needle-sharp stars as you would from your regular telescope.

Other uses

• Using the new H-alpha-CCD and the new SII-CCD filters you can obtain three-color images of emission line objects (gas nebulae) from locations with very strong light pollution. To do so, you would take an image in three different wavelengths, select each one as a color-channel in Photoshop and paste them together as one single color image.
• If you plan to create color images from emission line data, our CLS-CCD filter is a great choice for the Luminance channel.

Suitability

• Visual observation (dark skies): Unsuitable
• Visual observation (urban skies): Unsuitable
• Film photography: It depends, but very long exposure times
• CCD photography: Very good, huge contrast enhancement at S II-emission nebulas
• DSLR photography (original): Unsuitable
• DSLR photography (astro modified): Very good, huge contrast enhancement at S II-emission nebulas
• DSLR photography (MC modified): Very good, huge contrast enhancement at S II-emission nebulas
• Webcam / Video (Planets): Unsuitable
• Webcam / Video (Deep Sky): Unsuitable

Technical Data

• typ. transmission of 95% at both SII lines (671,7nm und 673,0nm)
• Complete blocking of all disturbing wavelength ranges in the infrared
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past