Baader CCD Complete Filters 1.25
Baader CCD Complete Filterset 1¼" LRGBC / H-alpha 7nm / OIII 8.5nm / SII 8nm (2mm glass thickness), consisting of 8 Filters (with low profile filtercell).
Baader's new LRGBC anti-reflection filters deliver improved color separation and image quality without annoying halos, the Baader Blue filter passes virtually all of the H-Beta and O-III lines, while the Green filter is able to capture all of the O-III line, without encroaching into the H-Beta line, in addition, the Green and Red filter passbands nearly touch, leaving only a sharp notch to block out the primary Mercury/Sodium light pollution line at 580nm. The high transmission everywhere else delivers the shortest combined exposures possible with every detector.
The Baader O-III perfectly isolates the two doubly ionized oxygen lines (496 and 501nm), through a very sharp and narrow bandpass 8.2 nm wide!, the narrowest of any O-III filter, while the Baader SII will block all unwanted sodium light pollution and longer wavelengths.
Baader's H-Alpha filters ultra narrow bandwidths with extremely high transmission rates enables high-contrast deep sky images, the high optical quality of the Baader narrowband filters guarantees no loss in sharpness or contrast. Each substrate is fine-optically polished plane parallel to deliver a smooth and accurate 1/4 wavefront over the entire surface. This special custom polishing operation sets Baader filters apart from the standard commercially precision polished filter substrates used by most other filter manufacturers.
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