Baader Filters OIII CMOS f/2 Ultra-Highspeed 36mm (70937)

OIII filters are designed to allow light with a wavelength of 501 nanometers to pass through. This corresponds to the spectral lines emitted by doubly ionized oxygen. These lines are characteristic of planetary nebulae and certain emission nebulae. By blocking out other wavelengths, the filter enhances contrast, making faint nebulae visible even in light-polluted skies.

Astrophotography Applications
These filters are particularly effective when used with monochrome cameras. For optimal results, images captured with OIII filters are often combined with those taken using H-alpha and SII filters. This combination produces high-contrast images that reveal faint nebulae in stunning detail.

Specifications

    Central Wavelength (nm): 500.7
    Half-Value Width (nm): 4
    Frame Material: Aluminium
    Coating: Reflex-Blocker™
    Filter Thickness (mm): 2
    Filter Size (mm): 36

Compatibility and Usage

    Appropriate for f/ratio: f/3.4 - f/1.8
    Type: Line filter
    Series: f/2 Ultra-Highspeed

Applications:

    Useful for photographs: Yes
    Visual observation: No
    Twin stars, Moon & Planets: Not suitable
    Nebulae & Galaxies: Ideal

This makes OIII filters an essential tool for astrophotographers aiming to capture detailed and high-contrast images of nebulae.