Skip to content

Astronomik H-Alpha 6 nm CCD Filter - 50 mm Round - HA6-50R

shipping truck Free shipping
SKU: ASF-HA6-50R

Astronomik 6 nm H-Alpha Filter - 50 mm Round


  • This H-Alpha CCD Filter from Astronomik comes in a round 50 mm threaded cell format
  • Made with regards to the finest technical standards to allow top-of-the-line optical performance for deep sky imaging with CCD cameras
  • H-Alpha light emissions are allowed to pass through while close to complete rest of the visual spectrum plus IR is blocked
  • FWHM of approximately 6 nm
  • All unwanted light pollution is blocked, making this filter optimal for imaging the remnants of supernovae as well as planetary nebulae
  • German-made for high optical quality!


For CCD imaging with instruments as fast as f/3.5, the Astronomik H-Alpha 6 nm Filter is an excellent narrow emission-line filter. Not suitable for visual or solar applications. This filter offers complete blockage of all areas of the spectrum with the exception of h-alpha light from emission nebulae.

The FWHM of the Astronomik 6 nm H-Alpha 50 mm Round Filter is optimized for maximum contrast between objects that emit H-alpha, such as emission nebulae, and the background sky. While the 12 nm is similar in function, the 6 nm offers higher contrast gain due to the smaller FWHM. The trade-off is the dimming or eradication of some background stars in the final image. Using the Astronomik 6 nm H-Alpha in conjunction with the 12 nm H-Alpha filter will provide maximum contrast in HII objects (6 nm) while keeping background stars visible (12 nm) in the final image.

Given that the Astronomik 6 nm H-Alpha CCD Filter completely suppresses the main offenders of light pollution, mercury (Hg) and sodium (Na) emissions lines, it makes for an excellent filter for use in a light-polluted environment.

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