Capture the stunning beauty of emission nebulae with the Celestron Narrowband Hα-Hβ-OIII Imaging Filter, tailor-made for the 8” Rowe-Ackermann Schmidt Astrograph (RASA). This filter is an essential tool for astrophotographers aiming to dramatically enhance their images of nebulae, especially in light-polluted conditions. It works by transmitting only the crucial hydrogen-alpha (Hα), hydrogen-beta (Hβ), and doubly ionized oxygen (OIII) wavelengths, which are key to emission nebulae, while blocking unwanted light pollution and sky glow.

This filter is specifically designed to complement the RASA's fast F/2 optics, unlike other filters with narrower bandpasses that may not be as effective with such fast optics. It fits seamlessly into the RASA 8's integrated filter mount, ensuring optimal optical performance without the need for additional adapters.

Constructed from high-quality Schott glass with anti-reflection coatings, the filter's surfaces are optically flat and free of defects. The aluminum cell, anodized in black, provides a durable and easy-to-handle frame with a knurled rim for easy installation. The filter's design effectively blocks out most of the visible spectrum, allowing only specific wavelengths through, making it an excellent choice for imaging popular emission nebulae like the North America Nebula, Lagoon Nebula, Orion Nebula, and Carina Nebula.

The Hα-Hβ-OIII Imaging Filter boasts an impressive transmission spectrum, with over 85% transmission at key wavelengths (486nm, 496nm/501nm, 656nm) and less than 0.5% elsewhere. This ensures high contrast images of nebulae without dimming them, only making the background darker.

Each filter comes with a foam-lined plastic storage case and a retaining ring, providing safe storage for the filter or the optical window glass that comes with your RASA. A unique spectral transmission graph, specific to your filter, is also included to verify its performance. The Celestron Narrowband Hα-Hβ-OIII Imaging Filter for the RASA 8 is the ideal choice for astrophotographers looking to explore the rich details of emission nebulae under various sky conditions.

Specifications