Celestron’s OIII narrowband filter fits onto a 1.25″ eyepiece, and isolates just the two doubly-ionized oxygen lines (496 and 501nm lines) emitted by planetary and emission nebulae, while blocking the rest of the overall spectrum of light. The result is extreme contrast between the black sky background and the faint photons of O-III light needed for detailed views of the Veil, Ring, Dumbbell, Crescent and Orion nebulae, and other objects.
Each filter has an ultra hard, vacuum-deposited, coating carefully designed to block all of the visual spectrum ranging from 400 to 700 nm. This eliminates the unnatural colored halos surrounding bright stars, which are common with O-III filters of less sophisticated coating technology. Your filter comes in a protective case, to keep it safe when not in use.
2-year Accessories Warranty included