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Astronomik H-Alpha 12 nm CCD Filter - SCT Rear Cell - HA12-SCT

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SKU: ASF-HA12-SCT

Astronomik H-Alpha 12 nm CCD Filter - SCT Rear Cell


  • Mounted in a round SCT rear cell
  • Designed with regards to the highest technical principles to allow the best possible optical performance or imaging deep sky objects
  • Permits H-Alpha emissions to pass while simultaneously blocking nearly the complete balance of the visual spectrum as well as IR
  • Approximately 12 nm FWHM
  • Blocks all undesirable light pollution and is ideal for imaging planetary nebulae and supernova vestiges
  • Made in Germany, a country noted for creating high quality optics!


More About the Astronomik H-Alpha 12 nm SC Rear Cell CCD Filter


This Astronomik SCT Rear Cell H-Alpha 12 nm CCD Filter is the optimal narrowband filter for CCD astrophotography. With a 12 nm FWHM, this filter is ideal for standard CCD cameras, allowing very fast optics to be employed. The f/number application range is spread from 1:2.8 to 1:15. The only time you'll have to be concerned with transmission losses and chromatic distortions, which can be an issue with other filters, is when excessively bright aperture ratios of 1:2 and more are involved. It should also be acknowledged that this filter has an up to 99% transmission. An additional asset of this 12 nm filter is the more convenient availability of guiding stars for cameras with an integrated autoguider.

Astronomik's H-Alpha 12 nm Filter enhances the contrast between objects, in this case between targeted objects with H-Alpha emission lines and the skyglow background. This filter also provides total suppression of emission lines from artificial sources such as mercury and sodium-vapor from street lamps, making it an excellent light pollution filter! Because of the high optical quality of the Astronomik H-Alpha 12 nm substrate, you won't be able to tell the difference between the razor sharp stars seen with a camera or with your regular telescope.

This SCT Rear Cell 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.