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Astronomik H-Alpha 12 nm CCD Filter - T-Mount - HA12-T

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SKU: ASF-HA12-T

Astronomik H-Alpha 12 nm CCD Filter - T-Mount


  • Mounted in a round T-Mount cell
  • Manufactured with regard to the highest technical standards to enable the best possible optical performance for deep sky CCD imaging
  • Simultaneously allows H-Alpha emissions to pass and blocks almost the entire remainder of the visual spectrum including IR
  • The Astronomik H-Alpha CCD Filter has a FWHM of approximately 12 nm
  • Ideal for imaging planetary nebulae and supernova remnants, the Astronomik H-Alpha 12 nm CCD Filter rejects all undesired light pollution
  • German-made for superior quality optics!


More About the Astronomik H-Alpha 12 nm T-Mount CCD Filter


For astrophotography with CCD cameras, this Astronomik H-Alpha 12 nm T-Thread 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 T-Mount 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 the Astronomik H-Alpha 12 nm T-Mount Filter.

The Astronomik H-Alpha 12 nm Filter increases the contrast between objects, in this case between objects with H-Alpha emission lines and the skyglow background. Additionally, this filter serves as a great light pollution filter by thoroughly blocking emission lines from artificial light sources such as those from mercury and sodium-vapor street lamps. Because of the high optical quality, very thin substrate of this filter, you'll be able to view the same needle-sharp stars you'd see with your normal telescope.

Delivered in a superior quality, long-lasting plastic storage case, the Astronomik H-Alpha 12 nm T-Mount CCD Filter provides total blockage of all unwelcome wavelengths in the visual and IR bands of the spectrum. As with all filters made by Astronomik, this filter is parfocal with all other Astronomik filters. Diffraction limited, your telescope's optical performance will not be compromised. This filter also offers peak resistance to scratching, aging, and high humidity.

Transmission Specifications


  • 97+% transmission for the H-Alpha line
  • Blocks nearly the whole remainder of the visual spectrum
  • Blocks unwanted wavelengths in the infrared


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