Baader Filters H-alpha/OIII/SII CMOS f/2 Ultra-Highspeed 1.25" (70956)

H-alpha filters pass light at a wavelength of 656nm, making them the best choice for narrowband H-alpha astrophotography. These filters provide high-contrast imaging and reveal rich details of nebulae, even in areas with significant light pollution.

OIII filters are narrowband filters designed for nebula observation. They allow a 3nm bandwidth of light centered on a wavelength of 500nm, corresponding to OIII emission lines, while blocking out all other light. This makes them ideal for isolating oxygen emissions in nebulae.

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

If you want to achieve the iconic look of Hubble Space Telescope (HST) images, such as the famous “Pillars of Creation” in the Eagle Nebula (Messier 16), the SII filter is an essential addition to your collection 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 delivers the distinctive Hubble-like appearance for many emission nebulae. These filters can also be used during moonlit nights, ensuring your imaging sessions are not interrupted by lunar brightness.

Specifications:

    Central Wavelength (nm): 656.3 (H-alpha), 500.7 (OIII), 671.7 (SII)
    Half-Value Width (nm): 3.5 (H-alpha), 4 (OIII and SII)
    Frame Type: 1.25"
    Mount Material: Aluminium
    Coating: Reflex-Blocker™
    Connection (to Telescope): 1.25"
    Filter Thickness (mm): 2

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

These H-alpha, OIII, and SII filters are indispensable tools for astrophotographers aiming to create stunning tri-color narrowband images with exceptional detail and contrast while minimizing interference from light pollution or moonlight.