Baader Filters H-alpha/OIII/SII CMOS f/2 Highspeed 31mm (70950)

H-alpha Filter
The H-alpha filter transmits light at a wavelength of 656nm. It is the best choice for narrowband H-alpha astrophotography, providing high-contrast imaging and revealing intricate nebula details, even in areas with strong light pollution.

OIII Filter
The narrowband OIII 3nm filter is specifically designed for observing nebulae. It allows a 3nm bandwidth of light centered on a wavelength of 500nm, corresponding to OIII emission lines, while blocking all other light.

SII Filter
The narrowband S-II 7nm filter transmits light at a wavelength of 672nm with a bandpass of 3nm. It is designed for nebula photography and is suitable for capturing most emission nebulae, planetary nebulae, and supernova remnants.

If you want to replicate the iconic look of Hubble Space Telescope (HST) images, such as the famous "Pillars of Creation" in the Eagle Nebula (Messier 16), the SII (sulfur) filter is an excellent addition to your collection after H-alpha (H-a) and OIII filters. Like the H-a filter, the SII filter operates in the deep red spectrum near 672nm. The combination of H-a, OIII, and SII filters enables tri-color narrowband imaging that provides the "Hubble look" for many emission nebulae. This imaging technique can even be performed when the moon is up, ensuring your equipment remains productive without long periods of inactivity.

Specifications

    Capacity
        Central wavelength (nm): 656.3 (H-alpha), 500.7 (OIII), 671.7 (SII)
        Half-value width (nm): 6.5
    Frame
        Type: Ring
        Mount material: Aluminium
        Coating: Reflex-Blocker™
    Compatibility
        Suitable for f/3.4 - f/1.8 systems
        Filter thickness (mm): 2
        Filter size (mm): 31
    General Information
        Type: Filters
        Build: Line filter
        Series: f/2 Highspeed
    Applications
        Useful for photographs: Yes
        Visually useful: No
        Twin stars: No
        Moon & planets: No
        Nebulae & galaxies: Yes

These filters are essential tools for astrophotographers seeking to capture detailed and vibrant images of emission nebulae while achieving stunning results with narrowband imaging techniques.