This Chroma H-beta 3nm Bandpass Filter - 50mm Square:
is useful for imaging nebulae and objects which are rich in ionized hydrogen. At the 486.1nm emission line, a narrow-band filter is required to separate H-beta from the nearby blue and green spectral lines. Though it is weaker than the H-alpha line, this is often used for visual detection as the longer red wavelength of H-alpha are difficult to detect by eye.
Type AS filter.
Optical Density Values:
All transmission and blocking (OD) data are actual, measured spectra of representative production lots. Spectra varies slightly from lot to lot. Optical density values in excess of 6 may appear noisy because such evaluations push the resolution limit of low light level measurements.