Orion 5581 1.25-Inch Oxygen-III Nebula Eyepiece Filter
- Orion's Oxygen-III (O-III) eyepiece filter reveals wondrous details when viewing cloudy nebulas.
- Filter transmits close to 90% of the light corresponding to 2 oxygen-III spectral lines at 496nm and 501nm for enhanced nebula detail in visual views.
- Completely blocks virtually all other visible wavelengths of light so views of nebulas are optimized.
- Eyepiece filter features high quality optical glass in a double-threaded, metal filter cell.
- Recommended for use with telescopes of 8" aperture or greater for best results and for visual use only.