31.7mm ND Filter OD 0.9
For perfect energy management during Lunar and Solar observation. NO reflections. NO stray light. NO ghosting.
Neutral Density (Grey) Filter 1 1/4", multi-coated / OD 0.9 T=12.5% (optically polished)
Planoptically polished with Phantom Coating Group Multi-coatings.
Special Filter Cell: Baader's special filter cell design offers unique features that enhance their reliability and usability. Though difficult to produce, the ultra-thin filter cell results in the maximum possible clear aperture, in order to minimize vignetting (1¼" Filter clear aperture is 27mm!, 2" Filter aperture is 45mm). The special threading has been designed to fit the wide variety of eyepieces and accessories.
Freedom from Ghosts and Halos: Baader Planetarium's filters have always been halo and ghost free. Baader balances each dielectric coating stack to avoid the ghosts and annoying halos that plague other manufacturers filters.
Stackability: Unlike most other filters, Baader Planetarium filters are truly designed to be stacked and combined. This is possible due to the high optical quality and highly efficient anti-reflection multicoatings. The ability to combine filters opens up many interesting possibilities, permitting unique spectral characteristics unachievable with any single filter.