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Astronomik H-Alpha 12 nm CCD Filter - 42 mm Round - HA12-42

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SKU: ASF-HA12-42

Astronomik H-Alpha 12 nm CCD Filter - 42 mm Round

  • Made for astrophotography, this Astronomik H-Alpha 12 nm CCD Filter is presented in a round 42 mm cell
  • Designed with the highest technical standards in mind to ensure the ideal optical performance for deep sky CCD imaging
  • Enables desired H-Alpha emissions to pass while obstructing nearly the entire rest of the visual spectrum including IR
  • 12 nm FWHM bandwidth
  • Obstructs all undesired light pollution, making it optimally suited for imaging planetary nebulae as well as supernova remnants
  • Made in Germany, a country recognized for their high quality optics!


More About Astronomik H-Alpha 12 nm CCD Filters

For astrophotography with CCD cameras, this Astronomik 42 mm H-Alpha Filter is the optimal narrowband filter. It features a 12 nm full width at half maximum (FWHM) for enabling the use of very fast optics with standard CCD cameras. The extension of f/number applications ranges from 1:2.8 to 1:15. Transmission losses and chromatic aberrations can be a problem with other filters. With the H-Alpha 12 nm CCD Filter, however, this will only become an issue when excessively bright aperture ratios of 1:2 or more are in play. This filter has a transmission of up to 99%. Furthermore, you'll find locating a guide star with cameras that have an integrated autoguider much easier with this filter.

Astronomik H-Alpha CCD filters enhance the contrast between objects, in this instance, it highlights the difference between objects with H-Alpha emission lines and the airglow background. Furthermore, this filter makes for an excellent light pollution filter as it rejects artifical light sources, such as mercury and sodium-vapor, entirely. Because of the superior optical quality of the Astronomik CCD H-Alpha substrate, you'll be able to view sharp, pinpoint stars identical to what you would be able to see from your regular telescope.

Delivered in a high-quality, long-lasting plastic storage container, the Astronomik 42 mm H-Alpha 12 nm CCD Filter is parfocal with all other Astronomik filters. It completely blocks all unwanted wavelengths in the visible and IR bands of the spectrum. This filter has a very thin substrate and is diffraction limited for maintaining the quality of fine images from your telescope. In addition, it offers very high resistance to impurities caused by scratching, aging, and high humidity.

Transmission Specifications

  • 97%+ H-Alpha line transmission
  • Blocks almost the entire rest of the visual spectrum
  • Blocks unwanted Infrared wavelengths


Please note this filter must NEVER be used for solar observing or imaging. Doing so will cause permanent damage to your eyes.