This fall and winter was dedicated to imaging the Cepheus area with a Hydrogen Alpha narrow band filter. However, at the low latitude from where I observe, Cepheus gets low on the horizon pretty early in winter. So I had to find another target to image during the late night. I decided to revisit an all time favorite, the Horse head nebula in Orion, and image it with the Borg 200 in Ha, SII and OII.
Ha is of course extremely bright, SII had some signal, although almost an order of magnitude lower than HA, and the Oxygen line is absent from the Horse Head area, but present in the neighboring Flame nebula (also about an order of magnitude below Ha).
Acquisition was very imperfect with clouds and humidity interfering, but I decided to give a go to the images non the less, processing with the Hubble palette (Ha mapped to green, SII to red and OIII to blue).