Baader Filters OIII CMOS f/3 Ultra-Highspeed 50.4mm (75581)

OIII filters are designed to allow light with a wavelength of 501 nanometers to pass through, corresponding to the spectral lines of doubly ionized oxygen. These lines are emitted by planetary nebulae and some emission nebulae. By blocking other wavelengths, the filter significantly enhances contrast, making faint nebulae visible for the first time.

Astrophotography is where OIII filters truly excel. They are best used with monochrome cameras, and 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 in stunning detail.

Specifications:

    Central Wavelength (nm): 500.7
    Half-Value Width (nm): 4
    Frame Type: Ring
    Mount Material: Aluminium
    Coating: Reflex-Blocker™
    Filter Thickness (mm): 3
    Filter Size (mm): 50.4

Compatibility and Applications:

    Appropriate for f/ratio: f/3.4 - f/2.3
    Type: Line filter
    Series: f/3 Ultra-Highspeed

Applications:

    Useful for photographs: Yes
    Visually useful: No
    Nebulae & Galaxies: Yes
    Moon & Planets: No

These OIII filters are essential tools for astrophotographers looking to isolate oxygen emissions and create high-contrast, detailed images of nebulae while reducing interference from surrounding light sources.