Celestron Oxygen-III (OIII) Visual Nebula Filter (2")

Celestron Oxygen-III (OIII) Visual Nebula Filter (2")

Due to high demand and global product shortages due to the pandemic, please call for availability.

Enhances contrast of emission and planetary Nebulae by rejecting light pollution from unwanted regions of the visible spectrum. Nebulae will be easier to see, as the sky is darkened.

Advanced dielectric multi-layer coatings are plasma-assisted and ion-beam hardened using the latest technology for durability and scratch resistance. This OIII filter achieves over 94% transmission across the extra-narrow bandpass, with sharp cutoffs, and total blockage of prominent light pollution lines.

Nebula filters are useful in and out of the city. Scopes larger than 4.5" will get the most benefit from this filter. For smaller scopes, try a UHC filter.


  • Passes doubly ionized Oxygen-III (500.7nm and 495.9nm wavelengths)
  • Made in Germany
  • Fits 2" optics

This filter is also available in a 1.25" format.