BAADER CMOS SHO F/2 Highspeed Narrowband CCD Filter Set
BAADER CMOS SHO F/2 HIGHSPEED FILTER
New in original cases $1400 posted
The new Baader CMOS-optimized SHO 3.5 / 4nm & 6.5nm Highspeed F/2 filters are precision-grade narrowband filters with high transmission at their respective emission lines. The Highspeed F/2 versions are specifically designed to work very well with modern highly-sensitive astronomy cameras and telescopes with extremely fast focal ratios faster than f/2.3 such as the Celestron RASA astrographs. The ultra-narrow 3.5 - 4nm bandpass make these ideal for imaging under light-polluted skies. The 6.5nm versions are recommended for most cases where there is not a great deal of light pollution.
The description you've posted says that there are 3.5/4nm and 6nm variations. You haven't stated which one you're actually selling here. You also haven't stated the size of the filters, but from the image it looks like 2".
Baader f/2 Highspeed Narrowband CCD Filter with preshift and LPFC (low profile filter cell): O-III - 2"
Baader's new f/2 Highspeed Narrowband Filters are designed especially for the delicate requirements of extremely fast astrograph optics, such as Hyperstar, RASA, and ultra-fast instruments from TEC/AP/ASA/etc. Conventional narrowband filters cause a heavy loss in transmission due to the strong CWL-shift. In extreme cases the CWL even shifts out of the FWHM (CWL= Center-wavelength; FWHM= full width half maximum).
Therefore these filters have a CWL-preshift which matches f/2 to f/3 perfectly. Also the FWHM is optimized. In spite of the typical line broadening with such fast optical trains they are able to deliver maximum contrast. For the first time these filters allow the effective use of extremely fast optics for high contrast imaging of emission nebulae. Using these filters between f/1,8 and f/3,5 shows a dramatic improvement compared to any regular set of narrowband-filters.
