Baader OIII CMOS Filter

Standard narrowband filters often suffer from a 'blue shift' when used with very fast telescopes, causing the transmission band to drift off the target wavelength. This filter is engineered with a specific bandpass shift to ensure that even at f/2, the OIII signal remains perfectly centered and fully transmitted.

While it is optimized for the spectral response and reflection characteristics of modern CMOS sensors, it will perform excellently with CCD cameras as well. The high-quality coatings and precision manufacturing benefit any sensor type by reducing internal reflections and halos.

Yes, the 50x50mm square format is a standard size for many professional-grade filter wheels. Please double-check your specific filter wheel's manual to ensure it accepts unmounted square filters of these dimensions.

This filter uses a precise, narrow bandpass to isolate the ionized oxygen emission line while aggressively blocking the wavelengths typically associated with artificial light pollution. This results in significantly higher contrast, allowing you to capture faint nebular details even from suburban or light-polluted skies.

Baader has applied advanced anti-reflection coatings specifically designed to minimize the halos often seen around bright stars when using narrowband filters. While no filter can eliminate halos entirely in every optical configuration, this model is engineered to keep them to an absolute minimum.