The 1-1/4" O-III narrowband filter isolates just the two doubly-ionized oxygen lines (496 and 501nm lines) emitted by planetary and emission nebulae, while effectively blocking the rest of the overall spectrum of light.

    It results in 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, as well as other objects. As lights of all other wavelengths are filtered out, the image presented to you have superior contrast and clarity compared to other broader band filters.

    Each filter has an ultra hard, vacuum-deposited coating carefully designed to block all of the visual spectrums ranging from 400 to 700 nm.This then eliminates the un-natural colored halos surrounding bright stars common with O-III filters with less sophisticatedcoating technology.

    Available in 1.25” and 2”.