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 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) 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 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) 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 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) 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 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 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 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 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 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 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.«

With this “filter” you can close an opening in filter wheels light-tight. This allows you to create dark images with cameras without their own shutter and to realize a “park” position of a filter wheel.The Astronomik Dark-Filters fit perfectly in all filter wheels of the brands ZWO, QHY, QSI, Starlight Xpress, SBIG, Moravian and Atik.

Astronomik offers a high-end series of RGB filters: the Astronomik Deep-Sky RGB filters are specifically designed to meet the needs of modern astrophotographers, delivering maximum image quality with all CMOS and CCD cameras. Use the Astronomik Deep-Sky RGB filter set to achieve images with unparalleled sharpness, contrast range, and vibrant colors.These filters are recommended for all modern CMOS and CCD cameras from companies such as ZWO/ASI, QHY, QSI, SBIG, ATIK, and ALTAIR. If you aim to capture the most beautiful images with your equipment, the Astronomik Deep-Sky RGB filters are the perfect choice!The Astronomik Deep-Sky RGB filters are the result of extensive, years-long research and development. We are proud to offer you the best RGB filters currently available for deep-sky imaging. The transmission range of these three filters is designed to allow the important emission lines in deep-sky photography to pass through, providing strong signals and vivid colors. Raw images captured with the Astronomik Deep-Sky RGB filter set can be easily combined into a stunning composite.Feedback from our customers has been extremely positive, mutually reporting smaller, sharper star images compared to conventional filters. This aligns with one of our primary development goals: achieving the highest contrast with pinpoint star images.During the development and testing of the Astronomik Deep-Sky RGB filters, we focused on the sensitivity curves of popular cameras used by modern astrophotographers. Instead of relying on manufacturer specifications, we conducted extensive measurements in our development lab. The result is excellent, balanced color reproduction and the best color contrast with all common sensors. The transmission characteristics and coating technology of the Astronomik Deep-Sky RGB filters ensure that no halos or reflections are visible. Even with bright stars in the field of view, nebulae and galaxies will be captured with the finest structures.In addition to the Astronomik Deep-Sky RGB filters, we offer three different Luminance filters (Astronomik L-1, L-2 and L-3 UV-IR Block). The different transmission ranges of each Luminance filter are designed to match the color correction of different telescopes in order to obtain the sharpest image with any optical design and camera, even with instruments with less-than-perfect color correction. Gallery of images taken with our Astronomik Deep-Sky RGB filters Additional note for photographers and observers under light-polluted skiesFor those working under light-polluted skies, consider using the Astronomik CLS CCD filter instead of a Luminance filter. The Astronomik CLS CCD filter captures luminance signals while effectively blocking high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamp lines, resulting in significantly less background noise. This substitution has been highly praised by customers worldwide, who report the advantages of the Astronomik CLS CCD filter for the luminance channel, making color deep-sky photography feasible in many regions.Suitability of the Astronomik Deep-Sky RGB filtersCMOS and CCD photography: Excellent for deep-sky imagingWebcam and video: Reasonable, used as a color filter for imaging planetsTechnical dataMaximum transmission typically 95% or betterAll Astronomik Deep-Sky RGB filters have IR- and UV-blocking 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 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.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 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 H-beta filter is specifically designed for visual observation, particularly effective with larger aperture instruments. It allows the H-beta emission line to pass almost unobstructed while blocking the rest of the spectral range. This filter significantly enhances contrast, making observation of objects like the Horse Head Nebula feasible with telescope apertures ranging from 10" (250mm) to 12" (300mm).For optimal use, the Astronomik H-beta filter is recommended for aperture ratios between 1:4.5 and 1:6.The filter is most effective when used with telescopes of 8" (200mm) or larger, ensuring sufficient light gathering. Its high optical quality ensures that stars remain sharp, comparable to observation without any filter.The Astronomik H-beta filter excels in enhancing the contrast between hydrogen nebulae and the sky background, crucial for visual observation even from dark sky areas. It allows for the observation of low-contrast hydrogen regions that are nearly imperceptible without filters.Overall, the Astronomik H-beta filter is a crucial tool for deep-sky observers seeking to explore the depths of H-beta emission regions.Suitability of the Astronomik H-beta filtersVisual observation (dark skies): Very good, but only suitable for a few observation objectsVisual observation (urban skies): UnsuitableTechnical data Typical transmission of 97% transmission at 486nm (H-beta)Transmission range: 480nm to 492nmFull-Width-Half Maximum (FWHM): 12nm  Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and 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.

Our popular Astronomik Narrowband-Emissionline filters are also available as a budget-friendly HSO filter set. This filter set offers an excellent opportunity to create false-color emission line images similar to those produced by the Hubble Space Telescope.Detailed insights into each Astronomik Narrowband-Emissionline filter’s specific applications can be found here: H-alpha, SII and OIII.The Astronomik H-alpha filter MUST NOT BE USED for solar observation!Difference between Astronomik 12nm and 6nm filtersThe choice between 12nm and 6nm Full-Width-Half-Maximum (FWHM) filters depends on your imaging conditions and camera type. There is no universal "best" option - each FWHM serves a specific purpose.The 12nm Astronomik Narrowband-Emissionline filters are better suited for use with typical DSLR cameras with CMOS sensors and CCD cameras with normal or high dark current or if you are observing from suburban or dark-sky locations. They are also the preferred choice for cameras with an integrated or dual guiding sensor, as they generally show more guiding stars compared to the 6nm filter.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 FWHM does not bring out more details in the object. The 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 compared to the 12nm filter. 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 Astronomik MFR coatingThe Astronomik MFR coating gives 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.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 Guaranteed 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 linesGuaranteed 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 lineGlass 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. 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 infrared (IR)-Block filter is the standard filter for lunar and planetary imaging with IR sensitive cameras, blocking IR-light while preserving the visible spectrum. By placing this filter in front of your camera, you can eliminate problems such as halos around objects and achieve a sharper overall image. The Astronomik IR-Block filter effectively blocks IR-light across all focal ratios.Blocking IR-light prevents ghost images. Optical systems typically corrected for the visible spectrum can have different focal points for visible and IR-light, resulting in a blurred ghost image in addition to the intended image. Since many cameras for imaging solar system objects are sensitive to IR-light, blocking it is critical to prevent this ghosting effect.
Additionally, the Astronomik IR-Block filter acts as protection against dust particles and airborne contaminants for telescopes and cameras. Other usesIt is an alternative to the Astronomik UV-IR Block filter if your camera has low sensitivity to UV-light.AlternativesUse the Astronomik UV-IR Block filter if your camera has high sensitivity to UV-light.Suitability of the Astronomik IR-Block filtersVisual observation: Suitable for dust protection onlyWebcam and video (planets): Very goodTechnical 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 L-RGB Type 2c filter set is specially designed for astrophotography with CCD cameras, enabling natural color reproduction of planets, stars, emission nebulae, and reflection nebulae. It features highest transmission rates for short exposure times.Both stars and objects emitting light in spectral lines are shown in their true colors, as if the objects were bright enough to be seen with photopic vision. This distinctive feature sets Astronomik filters apart from others. The Astronomik L-RGB Type 2c filter set divides the spectrum into its components: red, green, blue, and luminance. This allows for color separation with pure b/w CCD sensors, corresponding to the color sensitivity of the human eye according to DIN 5032. Astronomik focuses not just on capturing images but also on providing astrophotographers with a tool that facilitates a simple and elegant editing process. To maintain color accuracy, the Astronomik L-RGB Type 2c filter set is designed on the base of the sRGB color space, which is an industry standard used by most manufacturers of monitors, printers, and imaging software. AlternativesIf you want to take great deep-sky images with a modern CMOS or CCD camera from brands like ZWO/ASI, QHY, QSI, SBIG, ATIK, and ALTAIR, we recommend our Astronomik Deep-Sky RGB filter set.Suitability of the Astronomik L-RGB Type 2c filtersCMOS and CCD photography: Good color separation for RGB and L-RGB imagesWebcam and video: Excellent, used as a color filter for imaging planetsTechnical dataTypical transmission of 95-97%Suitable for all focal ratiosAll Astronomik L-RGB Type 2c filters have IR- and UV-blocking 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 onlyTechnical 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 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 MC-Clear glass is an optically polished and multi-coated special glass designed for Full-Spectrum modification of Canon EOS cameras. It allows the camera's CMOS sensor to capture a broader range of wavelengths, maximizing its spectral sensitivity. Available in various sizes to suit different Canon EOS models, the Astronomik MC-Clear glass primarily compensates for the optical light path of the camera’s original filters, which are removed during the modification. Additionally, it prevents dust particles from settling directly on the sensor, reducing the risk of visible dust on the image. The Astronomik MC-Clear glass itself has no filtering effect. The transmission is typically over 99.7% and it allows both infrared (IR) and ultraviolet (UV) light to pass through. For proper imaging, the modified Canon EOS camera requires an additional filter that blocks IR or visible light. The filter is dependent on the spectral range of interest and the optics used. For general photography, we recommend an Astronomik OWB Type 3 Clip-Filter, which restores the camera’s original sensitivity and white balance to the state before the modification. For astrophotography in visible light, at least an Astronomik UV-IR Block Filter should be used. For IR photography, we offer the Astronomik ProPlanet 642 BP, 742 and 807 Clip-Filters.

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 onlyTechnical 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.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 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 OIII visual filter is tailored for observation of OIII regions, particularly effective in both light-polluted or dark sky areas. It significantly enhances the contrast between objects emitting light at the OIII emission lines and the sky background.Specifically designed for gaseous and planetary nebulae, the Astronomik OIII visual filter features a narrow pass band for both OIII lines, ensuring substantial contrast gains even under optimal observation conditions. This attribute makes a critical difference in detecting faint supernova remnants and planetary nebulae, often revealing details that might otherwise be imperceptible.The filter's application spans aperture ratios from 1:3.5 to 1:15, most suitable for telescopes starting at 6" (150mm) aperture.The filter blocks emission lines from both high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps and natural airglow, while allowing the OIII lines to pass through with high transmission. This selective filtering enhances the contrast between the celestial object and the sky background, crucial for all visual observations.Overall, the Astronomik OIII visual filter excels in enhancing the visibility and detail of OIII emission regions. It is an indispensable tool for astronomers aiming to maximize the observational potential of gaseous and planetary nebulae.Suitability of the Astronomik OIII visual filtersVisual observation (dark skies): Very good, huge contrast enhancement for OIII-emission nebulaeVisual observation (urban skies): Very good, huge contrast enhancement for OIII-emission nebulaeTechnical dataTypical transmission of 95% at 496nm (OIII)Typical transmission of 95% at 501nm (OIII)Transmission range: 494nm to 506nmFull-Width-Half Maximum (FWHM): 12nm Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)Finely polished optical glass, free of any striae, residual stresses, and 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 opinionJohn C.: »I bought your 2'' visual OIII filter from OPT and found it superior to the others I have tried. No red dots. Excellent contrast in the veil nebula. Thank you for making such a fine filter!«

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.