Baader f/2 OIII High Speed Narrowband CCD Filter
for HyperStar, RASA & other Fast Systems - 1.25” Mounted
Baader f/2 Highspeed Narrowband filters are designed to work with astrographs faster than f/3, including HyperStar systems, RASA, and fast instruments from ASA, Astro-Physics, TEC, and more. All three Baader high-speed narrowband filters (Ha, OIII & SII) have a center wavelength (CWL) pre-shift that matches f/2 to f/3 systems beautifully, and since their FWHM is optimized, they are able to deliver maximum contrast.
When standard narrowband CCD filters are used with systems faster than f/3, they will suffer from a large loss of transmission due to the strong CWL shift. In some instances the filters will even shift out of the FWHM! However, when you use the special Baader High Speed Narrowband Filters with your f/1.8 to f/3.5 system, you will see a dramatic improvement when doing false color imaging of emission nebulae.
This OIII CCD filter is ideally suited for prime focus imaging. Together with the high speed Ha and SII (sold separately), even HyperStar users can achieve high contrast, false color “Hubble” style images! This filter is mounted in a 1.25” threaded cell.