Baader Filters H-alpha/OIII/SII CMOS f/2 Ultra-Highspeed 65x65mm (70962)

H-alpha filters transmit light at a wavelength of 656nm, making them the best choice for narrowband astrophotography. They excel in providing high-contrast imaging and revealing intricate details of nebulae, even in areas with significant light pollution.

OIII filters are designed for nebula observation, allowing a narrow 3nm bandwidth of light centered on a wavelength of 500nm. This corresponds to OIII emission lines while blocking all other light, making them perfect for isolating oxygen emissions in nebulae.

SII filters pass light at a wavelength of 672nm with a bandpass of 3nm, specifically designed for nebula photography. These filters are ideal 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 filter is an essential addition to your 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 delivers 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): 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

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.