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Astronomik H-Alpha 12 nm CCD Filter - 1.25" Round Mounted - HA12-1

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SKU: ASF-HA12-1

Astronomik H-Alpha 12 nm CCD Filter - 1.25"


  • The Astronomik H-Alpha CCD Filter is a photographic filter mounted in a 1.25" threaded cell
  • Designed with the finest technical standards in mind to permit the desired optical performance for deep sky CCD imaging
  • Allows H-Alpha light emissions to pass while blocking almost the entire remainder of the visual spectrum plus IR
  • The Astronomik H-alpha CCD Filter features a 12 nm FWHM
  • Blocks all undesirable light pollution and is ideal for imaging planetary nebulae and supernova vestiges
  • German-made for superior quality optics!


More About the Astronomik 1.25" H-Alpha 12 nm CCD Filter


For CCD applications, this Astronomik 1.25" Round Mounted H-Alpha 12 nm Filter is the optimal narrowband filter. Its 12 nm full width at half maximum (FWHM) is perfect for standard CCD cameras, permitting the use of extremely fast optics. The f/number application range spans from 1:2.8 to 1:15. Transmission deficits and chromatic distortion, a problem with other filters, only happen with Astronomik filters when excessively bright 1:2 plus aperture ratios are involved. This filter features a transmission of up to 99%. Additionally, with this 12 nm filter, you'll find it easier to locate guide stars for cameras with an incorporated autoguider.

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.

This 1.25" H-Alpha 12 nm CCD filter from Astronomik completely obstructs all undesired wavelengths in the visual and IR spectral areas. Like all Astronomik filters, it is parfocal with all other Astronomik filters. It contains a very thin substrate and is diffraction limited for maintaining your telescope's optical performance. This filter is also entirely resistant to scratching as well as the effects of high humidity and aging. Astronomik filters arrive in a durable plastic storage container of excellent quality.

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.