Baader Filters H-alpha/OIII/SII CMOS f/2 Ultra-Highspeed 50x50mm (70961)

H-alpha filters allow light at a wavelength of 656nm to pass through, making them the best choice for narrowband astrophotography. They deliver high-contrast imaging and reveal intricate details of nebulae, even in areas with strong light pollution.

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

SII filters transmit light at a wavelength of 672nm with a bandpass of 3nm, making them excellent for nebula photography. They are suitable for capturing most emission nebulae, planetary nebulae, and supernova remnants.

If you aim 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 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 appearance for many emission nebulae. These filters can also be used during moonlit nights, ensuring your imaging sessions continue uninterrupted.

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: Frames
    Mount Material: Aluminium
    Coating: Reflex-Blocker™
    Filter Thickness (mm): 2
    Filter Size (mm): 50 x 50

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 looking to create stunning tri-color narrowband images with exceptional detail and contrast while minimizing interference from light pollution or moonlight.