The Astronomik CLS filter is designed for visual observation and photography of nebulae, galaxies, and star clusters using telescopes and lenses. It completely blocks the emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, the majority of emissions from LED lamps as well as all lines of natural airglow while allowing the majority of visible light and nebulae emissions to pass through. This enhances the contrast between deep-sky objects and the night sky, making it ideal for photography and observation in light-polluted areas.Due to its wide passband, the Astronomik CLS filter passes a substantial amount of light, minimally dimming stars. The filter is designed to block as much unwanted light as possible while still transmitting the maximum amount of light from astronomical objects.20s exposures with JPEG data directly from the camera without further processing. Second image taken with the Astronomik CLS filter. (Canon EOS 6D astro-modified, ISO 6400, Canon EF24-105mm f/4L IS II USM @ 24mm / f/4)Other usesThe 1.25" and 2" socket models can be used for observations from light-polluted areas.AlternativesIf there is no built-in IR cut filter in your camera, a Astronomik CLS CCD filter is required.Suitability of the Astronomik CLS filtersCMOS and CCD photography: Good, requires an additional Astronomik IR-Block filterDSLR photography (original): Good, color balance is shifted but contrast is enhancedDSLR photography (astro-modified): Very good, color balance is close to perfectDSLR photography (MC-modified): Good, requires an additional Astronomik IR-Block filterGallery of images taken with our Astronomik CLS CCD filter (using the Astronomik CLS filter with a respective camera will result in identical images) Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical Data92% 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 bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik CLS CCD filter is designed for use with cameras that are intended for astronomical use. It enhances the contrast between all deep-sky objects and the sky background, making it ideal for astrophotography under light polluted skies.Its wider transmission range compared to UHC filters allows a greater amount of light to pass through, resulting in less dimming of stars. The Astronomik CLS CCD filter is optimized to block as much unwanted light as possible while allowing the maximum amount of light from the astronomical objects to pass through. The Astronomik CLS CCD filter completely blocks the emission lines of artificial light sources such as high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, the majority of emissions from LED lamps as well as all lines of natural airglow.The Astronomik CLS CCD filter is suitable for DSLR, CMOS, and CCD cameras and can be used with telescopes or lenses with focal ratios from 1:1.8 to 1:15.The integrated infrared(IR)-blocking layer makes it suitable for use with cameras without their own IR-block filter.30s exposures with JPEG data directly from the camera without further processing. Second image taken with the Astronomik CLS CCD filter. (Canon EOS M3 MC-modified, ISO 1600, Walimex 12/2.0)Other usesThe 1.25" and 2" socket models can be used for observations from light-polluted areas.For color images from emission line objects, the Astronomik CLS CCD filter is an excellent choice for the luminance channel.AlternativesFor cameras with an built-in IR cut filter or for visual observation, the Astronomik CLS filter is a more budget-friendly option.Suitability of the Astronomik CLS CCD filtersCMOS and CCD photography: Very good blocking of light-pollutionDSLR photography (original): Good, color balance is shifted but contrast is enhancedDSLR photography (astro-modified): Very good, color balance is close to perfectDSLR photography (MC-modified): Very good, color balance is close to perfectGallery of images taken with our Astronomik CLS CCD filter Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical Data95% transmission at 486nm (H-beta)95% transmission at 496nm (OIII)95% transmission at 501nm (OIII)97% transmission at 656nm (H-alpha)Transmission range: 450 to 520nm and 640 to 690nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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. Customer opinionMario Spénard: »I want to thank you for your magnificent CLS-CCD. I am using it with a standard unmodified Nikon D610 in a very light polluted area with some really nice result.«

The Astronomik H-alpha filter is ideal for imaging hydrogen nebulae from both light-polluted and dark observation sites. It significantly enhances the contrast between objects emitting light at 656nm (H-alpha line) and the sky background. The Astronomik H-alpha filter completely filters out the emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, as well as all lines of natural airglow and most of the distracting moonlight.With a narrow bandwidth of either 12nm or 6nm and high transmission rates, the filter effectively blocks all unwanted light from wavelengths other than 656nm from ultraviolet (UV) to infrared (IR).In areas with little light pollution, the background signal in images is usually limited by the sensor's dark current rather than light pollution. Therefore, further suppression of the sky background by reduction of the Full-Width-Half Maximum (FWHM) does not bring out more details in the object. The Astronomik H-alpha filter MUST NOT BE USED for solar observation!Imaging with Astronomik Narrowband-Emissionline filtersImaging with Astronomik Narrowband-Emissionline filters is the best way to capture great images from light-polluted sites as they effectively block all kinds of light pollution. An Astronomik H-alpha filter is usually the first step in this field of astrophotography, allowing you to take deep and contrasty images even under heavy light pollution or a full moon. Astronomik H-alpha filters are ideal for imaging all red-glowing nebulae. Astronomik OIII filters expand your imaging possibilities by capturing greenish and blueish structures, making planetary nebulae, star-forming regions and supernova remnants great targets. Completing your filter set with an Astronomik SII filter enables you to create false-color emission line images similar to those produced by the Hubble Space Telescope using the HSO (H-alpha, SII, OIII) palette. Difference between Astronomik H-alpha 12nm and 6nm filtersThe 6nm Astronomik Narrowband-Emissionline filters 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. They are also suitable if you have a camera with very low dark current or if you are observing from a location with extreme light pollution.The 12nm Astronomik Narrowband-Emissionline filters are better suited for use with typical DSLR cameras with CMOS sensors and CCD cameras with normal or high dark current. They are also the preferred choice for cameras with an integrated or dual guiding sensor, as they generally provide more guiding stars.Difference between Astronomik MFR and MaxFR coatingBoth the Astronomik MFR and MaxFR coatings give you the best out-of-band blocking over the entire wavelength range from UV to IR, extremely high contrast, minimized stray light, no halos and needle-sharp stars. 12nm MFR-coated filters can be used in all instruments with aperture ratios from f/3 to f/∞ without significant performance loss.6nm MFR-coated filters can be used in all instruments with aperture ratios from f/4 to f/∞ without significant performance loss.The MaxFR coating is designed to work perfectly with fast optical systems. For 12nm filters with MaxFR coating, this means unlimited usability from f/1.7 to f/8 and approximately 85% of the maximum transmission at a f/1.4.For 6nm filters with MaxFR coating, this means unlimited usability from f/2.2 to f/8 and approximately 90% of the maximum transmission at a f/2.Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataGuaranteed transmission of more than 90% (12nm and 6nm) at the H-alpha line (656nm)Typical transmission of 96% (12nm) and 93% (6nm) at the H-alpha line Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik MC-(multicoated) Clear filter serves dual purposes: as a dust protector or to maintain the optical depth of your imaging system. Dust protection: The robust coating ensures scratch resistance and durability, making the Astronomik MC-Clear filter the perfect choice for protecting your optics or sensors (e.g. Schmidt-Cassegrain telescopes, Schmidt-Newton telescopes, Maksutov systems, and DSLR cameras) from dust particles and airborne contaminants without affecting the sensitivity of the camera or the eye, altering colors or destroying the optical performance of your system.Parfocality: The Astronomik MC-Clear glass is manufactured to the same high standards as other Astronomik filters, ensuring it is parfocal with other Astronomik filters. This means it can be used interchangeably with other filters without affecting the focus. Additionally, it is multicoated to prevent unwanted reflections and does not block infrared (IR) or ultraviolet (UV) light.Astronomik MC-Clear filter are highly regarded by camera manufacturers worldwide for their superior coating and scratch resistance, available in various custom diameters.Other usesIt is an alternative to the Astronomik IR-Block or UV-IR Block (L-1, L-2, L-3) filters for photography in systems without refracting optical elements, e.g. Newton telescopes.Alternatives Use the Astronomik IR-Block or UV-IR Block (L-1, L-2, L-3) filters for photography in systems with refracting optical elements.Suitability of the Astronomik MC-Clear filtersVisual observation: For dust protection onlyCMOS and CCD photography: Good, to compensate the optical thickness of other Astronomik filters; dust protectionDSLR photography: For dust protection onlyWebcam and video: For dust protection onlyDifference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataSuitable for all focal ratiosTypical transmission: 97-99% Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik OIII filter is ideal for imaging nebulae showing oxygen emissions from both light-polluted and dark observation sites. It significantly enhances the contrast between objects emitting light at 496nm and 501nm (OIII lines) and the sky background. The Astronomik OIII filter completely filters out the emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, as well as all lines of natural airglow and most of the distracting moonlight.With a narrow bandwidth of either 12nm or 6nm and high transmission rates, the filter effectively blocks all unwanted light from wavelengths other than 496nm and 501nm from ultraviolet (UV) to infrared (IR).In areas with little light pollution, the background signal in images is usually limited by the sensor's dark current rather than light pollution. Therefore, further suppression of the sky background by reduction of the Full-Width-Half Maximum (FWHM) does not bring out more details in the object. Imaging with Astronomik Narrowband-Emissionline filtersImaging with Astronomik Narrowband-Emissionline filters is the best way to capture great images from light-polluted sites as they effectively block all kinds of light pollution. An Astronomik H-alpha filter is usually the first step in this field of astrophotography, allowing you to take deep and contrasty images even under heavy light pollution or a full moon. Astronomik H-alpha filters are ideal for imaging all red-glowing nebulae. Astronomik OIII filters expand your imaging possibilities by capturing greenish and blueish structures, making planetary nebulae, star-forming regions and supernova remnants great targets. Completing your filter set with an Astronomik SII filter enables you to create false-color emission line images similar to those produced by the Hubble Space Telescope using the HSO (H-alpha, SII, OIII) palette. Difference between Astronomik OIII 12nm and 6nm filtersThe 6nm Astronomik Narrowband-Emissionline filters 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. They are also suitable if you have a camera with very low dark current or if you are observing from a location with extreme light pollution.The 12nm Astronomik Narrowband-Emissionline filters are better suited for use with typical DSLR cameras with CMOS sensors and CCD cameras with normal or high dark current. They are also the preferred choice for cameras with an integrated or dual guiding sensor, as they generally provide more guiding stars.Difference between Astronomik MFR and MaxFR coatingBoth the Astronomik MFR and MaxFR coatings give you the best out-of-band blocking over the entire wavelength range from UV to IR, extremely high contrast, minimized stray light, no halos and needle-sharp stars. 12nm MFR-coated filters can be used in all instruments with aperture ratios from f/3 to f/∞ without significant performance loss.6nm MFR-coated filters can be used in all instruments with aperture ratios from f/4 to f/∞ without significant performance loss.The MaxFR coating is designed to work perfectly with fast optical systems. For 12nm filters with MaxFR coating, this means unlimited usability from f/1.7 to f/8 and approximately 85% of the maximum transmission at a f/1.4.For 6nm filters with MaxFR coating, this means unlimited usability from f/2.2 to f/8 and approximately 90% of the maximum transmission at a f/2.Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataGuaranteed transmission of more than 90% (12nm) and 88% (6nm) at the major OIII line (501nm)Typical transmission of 95% (12nm) and 92% (6nm) at the major OIII line Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik OWB (Original White Balance) Type 3 filter is not a traditional astronomical filter. Instead, it is designed to enable modified DSLR, CCD and CMOS cameras, which have had their inbuilt color correction or infrared (IR) filter removed or replaced, to be used for regular photography. This filter allows a modified DSLR to be used for both astrophotography and everyday photography, eliminating the need to dedicate a camera solely to astronomical tasks.DSLR cameras are modified for astronomical use by removing or substituting the inbuilt color correction filter with one that has a greater transmission of H-alpha light. When doing this, they lose their white balance capability for regular photography. The Astronomik OWB Type 3 filter restores the spectral sensitivity of the modified DSLR to its original range, making the camera functional for everyday photography again. Essentially, the Astronomik OWB Type 3 filter mimics the conventional built-in filter of the camera.The Astronomik OWB Type 3 filter allows the modified camera to work with its pre-set white balance settings, including the automatic white balance (AWB), which is not possible with modified DSLRs without this filter. Suitability of the Astronomik OWB Type 3 filtersDSLR photography (astro-modified): Very good, restores standard white balance for regular photographyDSLR photography (Full Spectrum modified): Very good, restores standard white balance for regular photography Technical data Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik ProPlanet 642 BP filter is the latest addition to the Astronomik ProPlanet infrared (IR)-pass filter series. This filter stands out for its versatility in daylight IR-photography, high-resolution lunar and planetary imaging, and deep-sky astrophotography of H-alpha nebulae."BP" stands for "Bandpass", indicating that the filter operates within a 200nm spectral window from 642nm to 842nm. In contrast to the other two Astronomik ProPlanet filters, it blocks the longer IR wavelengths. Together with the Astronomik ProPlanet 742 and ProPlanet 807 filters, you now have three choices to suit your IR imaging needs.Highlight of the Astronomik ProPlanet 642 BP filter: Three filter in one!
The highlight of the Astronomik ProPlanet 642 BP filter is its three-in-one functionality. Depending on the camera used, it serves as an excellent tool for daylight IR-photography, reducing seeing effects and enhancing contrast for lunar and planetary imaging. Additionally, it is an affordable H-alpha filter for those beginning deep-sky astrophotography of H-alpha regions. Extensive testing and development have ensured that this filter performs these tasks optimally, delivering stunning images.1) Daylight IR-photographyContrast-rich images with great color renditionClear "Wood-Effect" imagesNo hot spots from longer IRShort exposure times, similar to normal VIS-imagingPerfect choice for IR-videos2) High-resolution lunar and planetary imagingShort exposure timesEffective reduction of seeing (air turbulence)Enhanced contrast in the red areaNo ghost images and best sharpness due to blocking longer IR3) Deep-sky astrophotography of H-alpha nebulaeMaximal transmission of the H-alpha line at 656nmAbout 40nm Full-Width-Half Maximum (FWHM) with astro-modified DSLRsAmazing contrast under light-polluted skies or moonlightLow-priced filter for getting started in H-alpha imagingEasy focusing using the camera display plus LiveViewGuiding for AstrophotographyInstalling the Astronomik ProPlanet 642 BP filter in front of your autoguider camera dramatically improves guiding quality by minimizing image motion from one frame to the next.The features of the Astronomik ProPlanet 642 BP filter in detail1) Daylight IR-photographyThe development of the Astronomik ProPlanet 642 BP filter started with a focus on daylight IR-imaging using modified DSLR cameras. Normally, unmodified DSLRs have a built-in IR-blocking filter because their sensors are sensitive up to 1100nm. By removing this internal blocking filter through modifications like MC or Full Spectrum, the camera can be used for the fascinating field of IR- photography.The Astronomik ProPlanet 642 BP filter opens in the very deep red spectrum and allows light to pass through up to 842nm. This results in images that are perfect for channel swapping and offer excellent color differentiation in post-processing. The starting wavelength of 642nm combined with blocking longer IR provides particularly contrast-rich images.The following image demonstrates the impressive capabilities of the Astronomik ProPlanet 642 BP filter in IR-photography:Villadeati, a village on the hills of Piedmont (Italy) - Astronomik ProPlanet 642 BP filter compared to an UV-IR Block filter. (c) Domenico RotaDo you use the Astronomik ProPlanet 642 BP filter for daylight IR-photography? Share your best images with us!2) High-resolution lunar and planetary imagingHigh-resolution imaging of the moon and planets is an area of astrophotography that has seen remarkable advancements over the past 20 years. Today, amateurs around the world can capture images that were unimaginable for even the best-equipped professional observatories two decades ago. To engage in this field of astrophotography, you need a low-noise video camera, specialized image-processing software like AstroStakkert, Registax, or AviStack, and an IR-pass filter.Why infrared? Observers are familiar with the flickering of stars and planetary disks when viewed through an eyepiece or on a monitor. This flickering, caused by variations in air temperature and pressure, leads to a phenomenon known as "Seeing." The change in the refractive index of air bubbles, which causes the image to shift, is less pronounced in the IR spectrum than in the visual range, resulting in steadier and clearer images.While human eyes are not sensitive to IR light, CCD and CMOS sensors in modern cameras are. An IR-pass filter, such as the Astronomik ProPlanet 642 BP filter, blocks unwanted visible, short-wave light, allowing only the long-wave, calm IR light to reach the sensor. This greatly improves image sharpness and contrast.The amount of seeing changes very quickly, so there is no universal filter that will work every time. The Astronomik ProPlanet 642 BP filter is the latest addition to a line of products that includes the Astronomik ProPlanet 742 and ProPlanet 807 filters. This filter opens at 642nm and blocks longer IR, making it ideal for nights with relatively good seeing conditions. During its development, testers reported that the Astronomik ProPlanet 642 BP filter produced the best images, outperforming filters from other manufacturers in terms of sharpness and contrast.Thus, the Astronomik ProPlanet 642 BP filter is an essential tool for achieving high-quality, high-resolution lunar and planetary images, providing amateurs with the capability to capture professional-grade astrophotographs.Jupiter with Ganymed (c) Karl ThurnerJupiter with Ganymed (c) Hartwig LuethenDo you use the Astronomik ProPlanet 642 BP filter for lunar and planetary imaging? Share your best images with us!3) Deep-sky astrophotography of H-alpha nebulaeThe Astronomik ProPlanet 642 BP filter achieves nearly 100% transmission at the famous H-alpha line at 656nm. This means that all light from beautiful red H-alpha regions reaches your camera sensor while shorter wavelengths and most artificial light pollution are effectively filtered out. When used with a typical astro-modified DSLR, the filter provides a spectral window of about 40nm, resulting in a very dark background and high contrast. This makes it possible to capture stunning images of H-alpha regions even when the moon is up, as lunar stray light is also filtered out effectively.A common question from customers is, "How much longer do I need to expose with this filter?“. The answer is simple: you don't have to expose longer, but you can if you want to. Due to the high transmission rate of nearly 100%, the same amount of photons with a wavelength of 656nm will reach your sensor regardless of whether the filter is installed. However, with the Astronomik ProPlanet 642 BP filter installed, the sky background will remain very dark, allowing you to expose longer to collect more photons from your target without the background becoming overly bright.While narrowband-emissionline filters like the Astronomik H-alpha filters with 12nm or 6nm bandwidth perform this job even better by blocking more unwanted light, the Astronomik ProPlanet 642 BP filter is a very attractive option for beginners in this field of astrophotography due to its lower price. Additionally, real emission-line filters can be difficult for beginners to use because focusing is challenging with them. With the Astronomik ProPlanet 642 BP filter, there is usually enough light to use the LiveView monitor on your camera, making focusing much easier.Overall, the Astronomik ProPlanet 642 BP filter is the ideal filter for getting started in deep-sky astrophotography of H-alpha nebulae with a modified DSLR, providing excellent transmission, contrast, and ease of use for capturing beautiful deep-sky astrophotographs.California Nebula imaged with a Canon EOS 80D (modified) and Astronomik ProPlanet 642 BP filter (c) Thomas Tomz Henriksen, DenmarkDo you use the Astronomik ProPlanet 642 BP filter for H-alpha imaging? Share your best images with us!Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataMore than 95% transmission for wavelengths between 642nm and 840nmBlocking of wavelengths between 350nm and 630nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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. Customer opinion»(...) As expected, the detail resolution with the Astronomik ProPlanet 642 BP filter was unrivalled.(...) We would have needed this filter sooner :-).«

The Astronomik ProPlanet 742 filter is ideal for imaging the moon and planets, particularly Mars, with telescopes of 6" (150mm) aperture and larger. The filter only allows infrared (IR) light with wavelengths longer than 742nm to pass through, significantly reducing the effects of seeing compared to the visible spectrum. This results in much sharper images than typically expected from your equipment and location. Additionally, the filter effectively darkens the sky background during advanced dawn, enabling photography of planets and the moon even in daylight conditions. Jupiter, imaged with Astronomik L-RGB Type 2c filters (left) and Astronomik ProPlanet 742 filter (right)Comparing sharpness in IR-R-G-B at SaturnComparing L-RGB versus IR-RGB at SaturnOther usesBesides astrophotography, the filter provides stunning results in nature photography. When used as an EOS Clip-Filter in an MC or Full Spectrum modified DSLR, the filter cuts off the part of the spectrum where chlorophyll appears green and shows its high reflectivity in the near infrared. This creates stunning images of flora, with white trees and clouds against a nearly black background when photographed under blue skies in spring and summer.It darkens the sky background during twilight.It enables imaging of young stars in dust clouds and stellar nurseries.AlternativesIf the seeing is an issue and the instrument is 10" (250mm) or larger, the Astronomik ProPlanet 807 filter may be a better choice.Suitability of the Astronomik ProPlanet 742 filtersVisual observation: Unsuitable, the eye is insensitive to this spectral regionCMOS and CCD photography: Reasonable for special IR-photography, such as imaging chlorophyll or star-forming regionsDSLR photography (original): UnsuitableDSLR photography (astro-modified): UnsuitableDSLR photography (MC-modified): Very good for IR daylight photographyWebcam and video (planets): Very good, effectively rejects seeing problemsDifference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataMore than 96% transmission for wavelengths between 742nm and 1100nmBlocking of wavelengths between 350nm and 730nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik ProPlanet 807 filter is an ideal addition to the Astronomik ProPlanet 742 filter for imaging the moon and planets, especially Mars, with telescopes of 10" (250mm) aperture and larger when the seeing conditions are poor. The Astronomik ProPlanet 807 filter only allows infrared (IR) light with wavelengths longer than 807nm to pass through, significantly reducing the effects of seeing compared to the visible spectrum. This results in much sharper images than typically expected from your equipment and location. Another advantage is that it effectively darkens the sky background during advanced dawn, enabling the photography of planets and the moon even in daylight conditions.Other usesIt enables imaging of young stars in dust clouds and stellar nurseries.AlternativesIf the seeing is not to bad or if your telescope has an aperture smaller than 10" (250mm), we recommend using the Astronomik ProPlanet 742 filter.Suitability of the Astronomik ProPlanet 807 filtersVisual observation: Unsuitable, the eye is insensitive to this spectral regionCMOS and CCD photography: Reasonable for special IR-photography, such as imaging chlorophyll or star-forming regionsDSLR photography (original): UnsuitableDSLR photography (astro-modified): UnsuitableDSLR photography (MC-modified): Good, for IR daylight photography, but longer exposure timesWebcam and video (planets): Very good, effectively rejects seeing problems, particularly with telescopes larger than 10" (250mm) apertureDifference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataMore than 97% transmission for wavelengths between 807nm and 1100nmBlocking of wavelengths between 350nm and 790nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik SII filter is ideal for imaging nebulae showing sulfur emissions from both light-polluted and dark observation sites. It significantly enhances the contrast between objects emitting light at 671.7nm and 673nm (SII lines) and the sky background. The Astronomik SII filter completely filters out the emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, as well as all lines of natural airglow and most of the distracting moonlight.With a narrow bandwidth of either 12nm or 6nm and high transmission rates, the filter effectively blocks all unwanted light from wavelengths other than 671.7nm and 673nm from ultraviolet (UV) to infrared (IR).In areas with little light pollution, the background signal in images is usually limited by the sensor's dark current rather than light pollution. Therefore, further suppression of the sky background by reduction of the Full-Width-Half Maximum (FWHM) does not bring out more details in the object. Imaging with Astronomik Narrowband-Emissionline filtersImaging with Astronomik Narrowband-Emissionline filters is the best way to capture great images from light-polluted sites as they effectively block all kinds of light pollution. An Astronomik H-alpha filter is usually the first step in this field of astrophotography, allowing you to take deep and contrasty images even under heavy light pollution or a full moon. Astronomik H-alpha filters are ideal for imaging all red-glowing nebulae. Astronomik OIII filters expand your imaging possibilities by capturing greenish and blueish structures, making planetary nebulae, star-forming regions and supernova remnants great targets. Completing your filter set with an Astronomik SII filter enables you to create false-color emission line images similar to those produced by the Hubble Space Telescope using the HSO (H-alpha, SII, OIII) palette. Difference between Astronomik SII 12nm and 6nm filtersThe 6nm Astronomik Narrowband-Emissionline filters 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. They are also suitable if you have a camera with very low dark current or if you are observing from a location with extreme light pollution.The 12nm Astronomik Narrowband-Emissionline filters are better suited for use with typical DSLR cameras with CMOS sensors and CCD cameras with normal or high dark current. They are also the preferred choice for cameras with an integrated or dual guiding sensor, as they generally provide more guiding stars.Difference between Astronomik MFR and MaxFR coatingBoth the Astronomik MFR and MaxFR coatings give you the best out-of-band blocking over the entire wavelength range from UV to IR, extremely high contrast, minimized stray light, no halos and needle-sharp stars. 12nm MFR-coated filters can be used in all instruments with aperture ratios from f/3 to f/∞ without significant performance loss.6nm MFR-coated filters can be used in all instruments with aperture ratios from f/4 to f/∞ without significant performance loss.The MaxFR coating is designed to work perfectly with fast optical systems. For 12nm filters with MaxFR coating, this means unlimited usability from f/1.7 to f/8 and approximately 85% of the maximum transmission at a f/1.4.For 6nm filters with MaxFR coating, this means unlimited usability from f/2.2 to f/8 and approximately 90% of the maximum transmission at a f/2.Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataGuaranteed transmission of more than 90% (12nm and 6nm) at both SII lines (671.7nm and 673.0nm)Typical transmission of 96% (12nm) and 93% (6nm) at both SII lines Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik UHC filter stands out as the first choice for visual observation, offering enhanced contrast and detail in deep-sky objects that surpasses other filters on the market. With its Ultra High Contrast (UHC) design, the filter allows nearly 100% transmission of OIII and H-beta lines, effectively eliminating scattered light from various sources, including light pollution. This results in a significant enhancement of detail for gaseous and planetary nebulae against the sky background.Designed for versatility, the Astronomik UHC filter is effective in both urban and dark sky conditions, improving contrast for emission nebulae and other celestial objects for medium to large telescopes. It dramatically increases the visibility and detail of objects that are otherwise faint or obscured.The filter's application spans aperture ratios from 1:3 to 1:15, suitable for a wide range of telescopes. Compared to filters from other manufacturers, the Astronomik UHC filter excels in revealing more stars and finer details in celestial objects, maintaining the sharpness and optical quality expected from high-performance astronomical instruments.The filter works by blocking emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, the majority of emissions from LED lamps and all lines of natural airglow, while allowing H-beta and OIII lines to pass through. This selective transmission enhances the contrast between the sky background and observed objects.Additionally, the Astronomik UHC filter is recommended for observation of Jupiter's clouds and offers improved separation of double stars. In summary, the Astronomik UHC filter is indispensable for astronomers seeking to maximize visual clarity and contrast in deep-sky observation, making it an essential tool for all deep-sky observers alike.Alternatives For telescopes smaller than 5" (125mm), the Astronomik UHC-E filter with its wider pass band is more suitable.Telescopes with apertures exceeding 10" (250mm) may benefit from an Astronomik OIII visual filter as first filter.Suitability of the Astronomik UHC filtersVisual observation (dark skies): Very good, for telescopes of all aperture ratiosVisual observation (urban skies): Very good, for telescopes from 4“ (100mm) apertureDifference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataTypical transmission of 95% at 486nm (H-beta)Typical transmission of 95% at 496nm and 501nm (OIII)Typical transmission of 95% at 656nm (H alpha)Transmission range: 480nm to 505nm and above 645nm Full-Width-Half Maximum (FWHM): 25nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

The Astronomik UHC-E filter is tailored for deep-sky observation of emission nebulae and comets under light-polluted skies, especially ideal for smaller telescopes up to 5" (125mm) aperture. It enhances the contrast between these celestial objects and the sky background by blocking typical streetlight and LED lamp emissions, as well as all lines of natural airglow.With a Full-Width-Half Maximum (FWHM) of 45nm, the Astronomik UHC-E filter ensures a significant contrast boost while allowing a greater amount of starlight to pass through compared to its counterpart, the Astronomik UHC filter. This characteristic makes it particularly well-suited for smaller telescopes, enhancing visibility without compromising on the overall brightness. Additionally, its transmission range includes spectral lines, enhancing the observation of comets.In essence, the Astronomik UHC-E filter is a versatile tool for enhancing contrast under urban sky conditions, especially for observers using smaller telescopes to explore the depths of deep-sky objects and comets.Alternatives For telescopes larger than 5" (125mm), we recommend upgrading to the standard Astronomik UHC filter, which provides even greater contrast enhancement capabilities. For telescopes exceeding 8" (200mm), we suggest an Astronomik OIII visual filter as first filter.Suitability of the Astronomik UHC-E filtersVisual observation (dark skies): Reasonable, an Astronomik UHC filter is more suitableVisual observation (urban skies): Good, for telescopes up to 5" (125mm) apertureDifference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical dataTypical transmission of 94% at 486nm (H-beta)Typical transmission of 95% at 496nm (OIII)Typical transmission of 95% at 501nm (OIII)Typical transmission of 94% at 656nm (H-alpha)Transmission range: 465nm to 530nm and above 645nm Full-Width-Half Maximum (FWHM): 45nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.

Astronomik offers a range of three different ultraviolet (UV) and infrared (IR) blocking filters for the Luminance channel. These filters are designed to help you tune your setup to produce the sharpest, most contrast-rich images possible. The luminance channel is critical to a great final image because it provides the most signal, which means the filter should have the highest transmission possible with a wide spectral bandpass across the entire visible spectrum. This combination ensures the highest sensitivity and photon counts on your pixels.However, not all optical instruments or additional optical elements like correctors, field-flatteners, or reducers have a perfect color correction. A Luminance filter with too wide a bandpass can show chromatic aberration of the optical system, resulting in soft or bloated stars and making image processing difficult. To address this, Astronomik offers its line of Luminance filters: the L-1 filter with the widest spectral window, the L-2 filter with a standard spectral window, and the L-3 filter with the narrowest spectral window.Depending on the color errors of the instruments used, the Astronomik Luminance filter with the widest spectral window should be used.L-1 UV-IR Block filter: Ideal for optical systems free of chromatic aberrationL-2 UV-IR Block filter: Suitable for most optical systems with a corrector or flattenerL-3 UV-IR Block filter: Designed for refractors with less-than-perfect color correction to minimize bluish halos around starsThe transmission characteristics and coatings on the Astronomik Luminance filters are engineered to eliminate halos and reflections. Even with bright stars in the field of view, nebulae and galaxies are imaged with the finest structures and maximum contrast. Additional note for photographers under light-polluted skiesThe Astronomik CLS CCD filter is recommended as a replacement for the Astronomik Luminance filter. The Astronomik CLS CCD filter provides approximately the same amount of light in all three color channels while blocking nearly all unwanted light pollution, resulting in much deeper images with much less background noise from light-polluted observing sites.Difference between Astronomik standard and XT Clip-FiltersThe 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. 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 manufactured using the same durable coating technology as all Astronomik filters. More information about our XT-Filters can be found here.Technical data Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and bubblesExtremely scratch-resistant and durable coatingCompletely resistant against high humidity and aging effectsAstronomik MFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)Parfocal with other Astronomik filtersDiffraction-limitedOptimized spectral windowsDelivered in a high-quality, long-lasting filter boxDue to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore 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 coating is 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.