Celestron Oxygen III Filter 50.8 mm Schmalband

Celestron Oxygen III Filter 50.8 mm – Narrowband Filter for Enhanced Contrast

The Celestron Oxygen III Filter is a narrowband optical accessory designed for telescope observation. It isolates the oxygen-III emission lines at 496 nm and 501 nm, significantly increasing contrast on nebulae and planetary nebulae.

• Isolates oxygen-III emission lines at 496 nm and 501 nm for enhanced nebula contrast
• 50.8 mm (2-inch) diameter fits standard telescope eyepiece holders and accessories
• Narrowband design suppresses light pollution and broadband skyglow
• 24-month manufacturer warranty provides long-term investment protection

What sets the Celestron Oxygen III Filter apart

Unlike broadband filters that merely reduce overall brightness, the Oxygen III filter targets specific emission wavelengths produced by ionised oxygen in nebulae. This selective transmission reveals fine structural detail in planetary nebulae and emission nebulae that would otherwise be washed out by light pollution.

Ideal for...

Astrophotographers and visual observers who work from suburban or rural locations with moderate sky conditions. The filter is particularly suited for telescopes with focal ratios between f/4 and f/8, where narrowband filters deliver the strongest contrast improvement on diffuse deep-sky objects.

Application of the Celestron Oxygen III Filter

1. Insert the filter into the eyepiece holder or diagonal after the telescope is aligned
2. Select an oxygen-III-rich target such as the Orion Nebula, Ring Nebula, or Dumbbell Nebula
3. Observe at low to medium magnification (30–80×) for optimal transmission and field of view
4. For imaging, pair the filter with a monochrome camera and combine exposures through the filter with unfiltered luminance data