You can't turn up the luminosity on nebulas, but you can crank up the contrast between them and the night sky to reveal more of their wondrous detail. Our Oxygen-III filters provide extremely selective filtration to bring out elusive detail in diffuse and planetary nebulas. These filters do so by transmitting close to 90% of the light corresponding to the two oxygen-III spectral lines at 496nm and 501nm while completely blocking virtually all other visible wavelengths.
The results are remarkable. You'll see more detail than you ever could before in nebular gems such as the Swan, Ring, Dumbbell, Helix, and Eagle, to name a few. The O-III provides an even greater contrast boost on some objects than the UltraBlock narrowband filter. And for nebulas, every little bit helps! Try the O-III with a low-power 2" eyepiece and take in the whole Veil Nebula. Wow!
Due to the amount of light blockage, the O-III filter is recommended for telescopes of 8" aperture or greater, and for visual use only. It features the highest quality optical glass in a double-threaded, anodized aluminum cell.
Limited Warranty against defects in materials or workmanship for one year from date of purchase. This warranty is for the benefit of the original retail purchaser only. For complete warranty details contact us at 800-676-1343.