Astronomik Filters 2" 12nm H-alpha CCD filter (16752)

The Astronomik H-alpha 12nm filter is a narrowband filter designed specifically for CCD astrophotography. It allows H-alpha light from emission nebulae to pass through while blocking nearly all other wavelengths where CCD cameras are sensitive. Optimized with a full width at half-maximum (FWHM) of 12nm, it supports the use of fast optics and offers a transmission rate of up to 99%. The "Halo-Free" design, introduced in 2008, ensures superior image quality by eliminating halos around bright stars. This filter also allows for the availability of guiding stars when using cameras with built-in autoguiders, unlike narrower filters such as the 6nm version.

The Astronomik H-alpha filter enhances contrast between the H-alpha emission line and skyglow, making it highly effective in suppressing artificial light pollution from mercury and sodium lamps. It is suitable for aperture ratios ranging from 1:2.8 to 1:15, with minimal chromatic distortions or transmission losses unless used with extremely bright aperture ratios of 1:2 or faster.

Specifications

• Capacity:
  • Connection (to the telescope): 2"
  • Coating of optical system: Multiple
  • Mount material: Aluminium
  • Frame: 2"
• General:
  • Series: H-alpha 12nm
  • Type: Filters
  • Type of build: Line filter

Area of Application

• Useful for photographs: Yes
• Anti light-pollution: Yes
• Hydrogen nebulae: Yes