Baader OIII Filter 10NM HBW Visual
The Baader Planetarium OIII Filter offers the highest contrast views of diffuse and planetary nebula, including the Veil, Lagoon, Swan, Ring, and Dumbbell.
Planoptically polished for the highest image quality. Only 10 nm FWHM with a 93% transmission rate. Perfect for planetary observation producing very high contrast levels.
For many objects, the Baader O-III reveals a level of intricate detail that rivals the best deep sky photographs, the Baader O-III perfectly isolates the two doubly ionized oxygen lines (496 and 501nm), through a very sharp and narrow bandpass . Unlike other O-III filters, the Baader O-III completely blocks longer and shorter wavelengths, this is why some O-III filters appear red, instead of the correct 500 nm Teal color. The result is the highest contrast achievable in an O-III filter.
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 mfgr's 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.
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 (there is significant variation between the 1¼” filter threading used by eyepiece and accessory manufacturers). The front 'crown' of the filter incorporates milled notches which make handling and threading the filter a more secure operation in the dark.