The red (Ha signal) is SH-129, the Flying Bat Nebula. The blue Squid Nebula (Oiii signal) in this image was discovered only 12 years ago (2011) by a French amateur astrophotographer named Nicholas Outters. The reason for this late discovery is that the oxygen signal is very weak and difficult to see. I had to take 120 exposures with a duration of 10 minutes each to obtain this signal, in total 20 hours just for the Squid Nebula. And 10 hours of exposures was obtained for the Bat Nebula. In addition RGB filters were used to photograph the stars, in total 1 hour exposure (20 minutes for each filter, 1 minute exposures). For this image I used the Nebula rig (see equipment page). These nebulae are located some 2300 light years away from earth in the Cepheus region.
Hydrogen (Ha) starless signal
Oxygen (Oiii) starless signal
Shown above are the stacked starless images of the Ha and Oiii signals that I processed in PixInsight. You can appreciate the very weak oxygen signal despite a total of 20 hours exposure for this signal alone making processing quite difficult. Using a narrow band filter with less bandwidth (e.g. 3 nm instead of 7 nm as used here) should improve the image quality. These 3 nm filters, however, are quite expensive.