Baader Filters OIII CMOS Ultra-Narrowband 50.4mm (70883)

The OIII filters are designed to allow only light with a wavelength of 501 nanometers to pass through, corresponding to the spectrum lines of double-ionized oxygen. These lines are emitted by planetary nebulae and some emission nebulae, ensuring these objects remain visible while blocking out other light sources. This filtering effect enhances contrast and makes faint nebulae visible for the first time.

For astrophotography, OIII filters are best used with monochrome cameras. To create high-contrast images that clearly depict faint nebulae, images taken with OIII filters should ideally be combined with those captured using H-alpha and SII filters.

Specifications

Capacity
Central Wavelength (nm): 500.7
Half-Value Width (nm): 4

Frame
Type: Ring
Mount Material: Aluminium
Coating: Reflex-Blocker™

Appropriate for Telescopes
Aperture Ratio Range: f/10 to f/3.5

Filter Thickness
Thickness (mm): 2

Filter Size
Size (mm): 50.4

General Information
Type: Filters
Build Type: Line filter
Series: Ultra-Narrowband

Area of Application
Useful for Photographs: Yes
Visually Useful: No
Twin Stars: No
Moon & Planets: No
Nebulae & Galaxies: Yes