Baader Filters SII CMOS f/2 Ultra-Highspeed 65x65mm (70948)

SII filters are narrowband filters specifically designed for nebula photography. They pass light at a wavelength of 672nm with a bandpass of 3nm, making them perfect for capturing most emission nebulae, planetary nebulae, and supernova remnants.

If you aim to replicate the iconic appearance of Hubble Space Telescope (HST) images, such as the renowned “Pillars of Creation” in the Eagle Nebula (Messier 16), the SII filter is an essential addition to your astrophotography setup after H-alpha and OIII filters. Like the H-alpha filter, the SII filter is a deep red filter near 672nm. Together, H-alpha, OIII, and SII filters enable tri-color narrowband imaging that produces the distinctive Hubble-like look for many emission nebulae. These filters can also be used during moonlit nights, allowing you to continue imaging without delays caused by lunar brightness.

Specifications:

    Central Wavelength (nm): 671.7
    Half-Value Width (nm): 4
    Frame Type: Frames
    Mount Material: Aluminium
    Coating: Reflex-Blocker™
    Filter Thickness (mm): 2
    Filter Size (mm): 65 x 65

Compatibility and Applications:

    Appropriate for f/ratio: f/3.4 - f/1.8
    Type: Line filter
    Series: f/2 Ultra-Highspeed

Applications:

    Useful for photographs: Yes
    Visually useful: No
    Twin stars, Moon & Planets: Not suitable
    Nebulae & Galaxies: Ideal

The SII filter is an indispensable tool for astrophotographers looking to create stunning tri-color narrowband images with exceptional detail and contrast while minimizing interference from light pollution or moonlight.