Antlia ALP-T Dual Band 5nm SII & H-beta Filter – 2” Mounted

Description

Antlia ALP-T Dual Band 5nm SII&Hb Filter

The ALP-T dual band 5nm SII&Hb filter is a dual line-pass filter, which lets the deep red Sulfur-II line and the blue Hydrogen-Beta line through and is used with one-shot color (OSC) cameras such as DSLR’s or astronomical OSC cameras. It is a significant addition to the popular Antlia ALP-T dual band 5nm Ha&OIII filter and enables false-color images and narrow-band nebula images using OSC. When capturing data with this filter, the nebulae are recorded with greater contrast against the background than without it.

The combination of these two dual band filters allows extreme narrow-band images with OSC cameras by capturing the spectral data from 4 channels i.e. Ha/OIII/SII/Hb. The spectrum of these four channels can be separated and recombined into various colour palettes in your post-processing. The resulting images can be used for luminance contrast enhancement of traditional RGB-balanced images or creation of images in various popular false-color palettes such as H-O-Hb, S–H–O, H-S-OHb, H-O-O etc.

Why design SII&Hb bands pass instead of OIII&SII bands?

The filter is dedicated to capture H-beta and SII emission lines. We know that SII is singly ionized sulfur that emits light in the deep red part of the spectrum, beyond H-alpha, but the contribution of H-beta to emission lines in nebulae is frequently overloo