Baader Planetarium 2" f/2 Highspeed-Filterset, Includes H-alpha, O III and S II Filter

• f/2 Highspeed Filterset consisting of 3 Filter: H-alpha, O III and S II. Highspeed Narrowband Filter are designed especially for the delicate requirements of extremely fast astrograph optics, in particular Hyperstar and RASA
• Conventional narrowband filters cause a heavy loss in transmission due to the strong CWL-shift. In extreme cases the CWL even does shift 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.
• 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 to use fast optics really effectively with high contrast emission nebulae imaging. Using these filters between f/1.8 and f/3.5 shows a dramatic improvement compared to any regular set of narrowband-filters.