Baader Planetarium 1.25" f/2 Highspeed-Filterset, Includes H-alpha, O III and S II Filter

An exceptional 1.25" f/2 Highspeed-Filterset, this product includes three distinct filters: H-alpha, O III, and S II. These Highspeed Narrowband Filters are meticulously designed to meet the precise requirements of ultra-fast astrograph optics, specifically Hyperstar and RASA systems.

Traditional narrowband filters often result in significant transmission loss due to the pronounced CWL-shift. In severe instances, the CWL may shift out of the FWHM (CWL= Center-wavelength / FWHM= full width half maximum). To counter this issue, these filters feature a CWL-preshift that perfectly aligns with f/2 to f/3 optics.

The FWHM of these filters is optimized to ensure maximum contrast, even with the typical line broadening associated with such fast optical trains. These filters mark a significant advancement in the field, as they allow for the effective use of fast optics in high contrast emission nebulae imaging.

When used between f/1.8 and f/3.5, these filters demonstrate a dramatic improvement over standard sets of narrowband filters. This 1.25" f/2 Highspeed-Filterset is a must-have for any serious astrophotographer or astronomy enthusiast looking to enhance their imaging capabilities.