Baader Filters H-alpha/OIII/SII CMOS f/2 Highspeed 1.25" (70949)

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

OIII Filter
The narrowband OIII 3nm filter is designed for observing nebulae. It allows a 3nm bandwidth of light centered on a wavelength of 500nm, corresponding to OIII emission lines, while effectively 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 specifically designed for nebula photography and is suitable for capturing most emission nebulae, planetary nebulae, and supernova remnants.

If you want to replicate the iconic appearance 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. Additionally, this imaging technique can be performed even 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
        Size: 1.25"
        Mount material: Aluminium
        Coating: Reflex-Blocker™
    Connection to Telescope
        Size: 1.25"
    Compatibility
        Suitable for f/3.4 - f/1.8 systems
        Filter thickness (mm): 2
    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 aiming to capture high-quality images of emission nebulae and achieve stunning results with narrowband imaging techniques.