Astronomik Filters CCD Canon EOS XL H-Alpha clip-filter (43703)

The Astronomik H-alpha 12nm filter is a narrowband filter specifically designed 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. With a full width at half-maximum (FWHM) of 12nm, this filter is optimized for use with common CCD cameras and fast optics, offering 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 supports guiding stars for cameras with built-in autoguiders, unlike narrower filters such as the 6nm version. It is effective 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. Additionally, it completely suppresses artificial light pollution from mercury and sodium lamps, making it ideal for capturing high-contrast images of nebulae even in heavily light-polluted areas.

Please note that while the Clip-Filter system is compatible with Canon EF lenses and third-party lenses (Sigma, Tamron, etc.), it cannot be used with Canon EF-S lenses.

Specifications

• Capacity:
  • Half-value width (nm): 12
  • Connection: EOS Clip
  • Coating of optical system: Multiple
  • Frame: Clip-Filters
  • Appropriate for: Canon EOS
• General:
  • Series: H-alpha 12nm
  • Type: Filters
  • Type of build: Line filter

Area of Application

• Useful for photographs: Yes
• Hydrogen nebulae: Yes
• Anti light-pollution: Yes
• Visually useful: No