ALP-T Dual Band 5nm H-Beta and SII

This dual band narrowband filter features very narrow 5nm pass bands for H-Beta and Sulfur-II, designed to increase contrast of nebulae that emit in the sulfur and H-beta range using one-shot color (OSC) cameras. As a dual line-pass filter, it lets the deep red Sulfur-II line and blue Hydrogen-Beta line through for use with DSLR and astronomical OSC cameras. When combined with the companion ALP-T Dual Band 5nm Ha&OIII filter, it enables extreme narrow-band imaging by capturing spectral data from four channels (Ha/OIII/SII/Hb) that can be separated and recombined into false-color palettes. The advanced multi-coatings provide almost total suppression of optical density (OD) 4.5 on unwanted wavelengths from light pollution, moonlight, and airglow, creating a superior signal-to-noise ratio and better contrast in OSC images.