Baader Filters OIII CMOS f/2 Highspeed 1.25" (70914)

OIII filters allow only light with a wavelength of 501 nanometers to pass through. This corresponds to the spectral lines of doubly ionized oxygen. These lines are emitted by planetary nebulae and certain emission nebulae, making these objects visible while blocking out the rest of the light. This significantly enhances contrast and makes faint nebulae observable for the first time.

Astrophotography: These filters are most effective when used with monochrome cameras. For optimal results, images captured with OIII filters should be combined with those taken using H-alpha and SII filters. This combination produces high-contrast images that clearly depict faint nebulae.

Specifications:

Capacity

    Central wavelength (nm): 500.7
    Half-value width (nm): 6.5

Frame

    Size: 1.25"
    Material: Aluminium

Optical Coating

    Type: Reflex-Blocker™

Connection to Telescope

    Size: 1.25"

Appropriate for...

    f-ratio range: f/3.4 - f/1.8
    Filter thickness (mm): 2

General Information

    Type: Filters
    Build Type: Line filter
    Series: f/2 Highspeed

Area of Application:

    Useful for photographs: Yes
    Visually useful: No
    Twin stars: No
    Moon & Planets: No
    Nebulae & galaxies: Yes