{"id":30254,"date":"2025-10-06T11:33:36","date_gmt":"2025-10-06T09:33:36","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&p=30254"},"modified":"2026-07-20T14:50:37","modified_gmt":"2026-07-20T12:50:37","slug":"baader-narrowband-oiii-filter-cmos-f-2-highspeed-50-4mm","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/baader-narrowband-oiii-filter-cmos-f-2-highspeed-50-4mm\/","title":{"rendered":"Baader Narrowband OIII Filter CMOS f\/2 Highspeed 50.4mm"},"content":{"rendered":"

Baader Narrowband OIII Filter CMOS f\/2 Highspeed 50.4mm: narrowband for extremely fast optics<\/strong><\/h2>\n\n\n\n

Doubly ionized oxygen (OIII) is the dominant emission line of planetary nebulae and supernova remnants such as the Veil Nebula. This filter isolates that line with a half-width of 6.5 nm. The f\/2 Highspeed version is specially designed for extremely fast optics: the passband is pre-shifted, so the filter continues to work at the correct wavelength for apertures from f\/3.4 to f\/1.8.<\/p>\n\n\n\n

In fast optical systems like the Celestron RASA or Hyperstar, light strikes the filter at steep angles, causing the transmission band of a standard filter to shift and leading to signal loss. The Highspeed series compensates for this and maintains full transmission at the OIII line.<\/p>\n\n\n\n

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CMOS-optimized<\/h4>\n\n\n\n

The filters are optimized for modern CMOS cameras: the 6.5 nm FWHM has been chosen for balanced exposures across the channels, and the Reflex-Blocker hard coating suppresses halos around bright stars. Blackened edges and the Life-Coat edge seal make the coating resistant to years of use.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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What you use this filter for<\/h4>\n\n\n\n

This filter is designed for planetary nebulae, the Veil Nebula, and oxygen-rich regions of emission nebulae. The narrow bandpass makes the sky background deeply dark, even under light-polluted skies or moonlight, and makes the blue-green nebula structures stand out maximally.<\/p>\n<\/div>\n<\/div>\n\n\n\n

Featured accessories<\/h3>\n\n\n\n

Combine this filter with the other two lines in the series (H-alpha, OIII, and SII) for complete narrowband or Hubble palette captures.<\/p>\n\n\n\n

For whom yes and for whom no<\/h3>\n\n\n\n