The 1-1/4"Svbony H -Beta narrowband filters isolates just 486nm (blue) linear spectral nebula, while blocking the rest of the overall spectrum of light. Tmax @ 486nm H -Beta light transmittance is above 90%
Each Svbony filter has an ultra hard, vacuum-deposited coating carefully designed to observe the Orion Horsehead Nebula and the California Nebula, which are difficult to captureThis eliminates the un-natural colored halos surrounding bright stars common with H-Beta filters of less sophisticated coating technology.
Fortunately, many sources of light pollution have relatively discreet emission spectra; they emit primarily at specific wavelengths of light. By strategically blocking these wavelengths, the filter greatly reduces the effects of light pollution without degrading overall image quality.
The H-Beta Filter is suitable for1-1/4" eyepieces
The 1-1/4"Svbony H-Beta filters suitable for viewing bright nebulae, and matching with large-aperture telescopes to observe linear spectrum nebulae,such as the M42 Orion Nebula under severe light pollution, emission nebulae, planetary stars & supernova remnants.