Antlia SHO 3nm Narrowband PRO Highspeed Filters

Antlia SHO 3nm Narrowband PRO Highspeed Filters

Antlia's SHO 3nm Pro Highspeed Filters are further optimized for high-speed imaging systems by pre-shifting the center wavelength. This specially-optimized version will provide significantly SNR(Signal to Noise Ratio) for the fast telescopes with focal ratio between f/2.6 and f/3.6 than the standard 3nm Pro version.

The optical light path of a telescope is cone-shaped, which creates an angle, and the center wavelength of the interference filter will shift toward shorter (blue) wavelengths as the angle of incidence((AOI) increases; the greater the angle， the greater the shift. The amount of beam deviation depends on the refractive index and the thickness of the substrate. The blue shift data by the simulation indicates that at a focal ratio of f/2.6, the angle of incidence of the light cone is 10°and its bandwidth shift 2.2nm to shorter wavelengths. Therefore, the Highspeed 3nm Pro narrowband filters are designed to be pre-shifted by 1.2nm towards the longer (red) end in order to compensate for the Blueshift and ensure high signal acquisition by telescopes with fast focal ratios.