Baader Filters OIII CMOS f/2 Highspeed 31mm (70915)

OIII filters only permit 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 some emission nebulae, allowing these objects to remain visible while the filter blocks out other light. This enhances contrast and reveals faint nebulae that were previously invisible.

Astrophotography: These filters are best suited for use with monochrome cameras. For optimal results, images captured using OIII filters should be combined with those taken with H-alpha and SII filters. This combination produces high-contrast images that clearly display faint nebulae.

Specifications:

Capacity

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

Frame

    Type: Ring
    Mount material: Aluminium

Optical Coating

    Type: Reflex-Blocker™

Appropriate for...

    f-ratio range: f/3.4 - f/1.8
    Filter thickness (mm): 2
    Filter size (mm): 31

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