Baader Planetarium 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted

A 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted, is a specialized narrowband filter, meticulously engineered to meet the intricate needs of ultra-fast astrograph optics, specifically Hyperstar and RASA. Traditional narrowband filters often suffer from significant transmission loss due to a pronounced CWL-shift. In severe instances, the CWL may even shift out of the FWHM (CWL= Center-wavelength / FWHM= full width half maximum). To counteract this, our filters feature a CWL-preshift that perfectly aligns with f/2 to f/3 optics.

The FWHM of this high-speed Oxygen-III Nebula Filter is expertly optimized. Despite the common line broadening associated with fast optical trains, this filter is capable of delivering maximum contrast, making it an essential tool for astrophotography.

For the first time, these filters enable effective use of fast optics for high contrast emission nebulae imaging. When used between f/1.8 and f/3.5, these filters demonstrate a significant improvement over standard sets of narrowband filters. This 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted, is a game-changer for astrophotographers seeking to capture the breathtaking beauty of the cosmos with unparalleled clarity and contrast.