BAADER CALCIUM GEN-II FILTER 1.25"

BAADER CALCIUM GEN-II FILTER 1.25"

Description:
The Baader Calcium GEN-II 1.25" filter reveals the transition zone between the solar photosphere and lower chromosphere, displaying detailed structures like the chromospheric network, supergranulation cells, and Ellerman Bombs. These features are invisible in white light or H-alpha.

Operating at 394 nm in the near UV, this filter is strictly for imaging with a camera and never for visual observation. It performs best with monochrome cameras and reflector telescopes; some refractors may still work, but sharpness at this wavelength may vary.

The filter includes a 20x30 cm Baader AstroSolar Photo Film OD 3.8 for building your own front-mounted solar filter. Alternatively, it can be used behind a Herschel wedge with modified neutral density.

Thanks to improved manufacturing, this single-stack GEN-II filter reaches a FWHM of only 5 nm, making dual filters unnecessary. Its slim 6 mm cell fits standard filter wheels and drawers. CMOS-optimized with Life-Coat™, Reflex-Blocker™, blackened edges, and strict parfocality tolerances.

Technical specifications:
– Type: Narrow-band UV filter (Calcium, 394 nm)
– Bandwidth (FWHM): 5 nm
– Use: solar imaging only (camera)
– Compatible with: barlow lenses, filter wheels, UFC drawers, T2 threads, 1.25" nosepieces
– Format: mounted, 1.25", standard thread
– Cell height: 6 mm
– Coatings: Life-Coat™, Reflex-Blocker™, blackened edges
– Included: AstroSolar Photo Film OD 3.8 (20x30 cm)

Additional information:
This filter is not for visual use and must be used with a front solar filter like AstroSolar film or a photographic Herschel wedge. Calcium-K solar imaging requires UV-sensitive monochrome cameras and optimized optics. This GEN-II model replaces the older K-Line stack filter.