Description

This region is in a very well known area of the sky, but its neighbors draw more attention from astrophotographers. Close to Deneb, at the opposite side of the North America and Pelican nebulae, lies this emission nebula complex. I'd been wanting to image this some time, and capturing this one took a while due to vacation and bad weather. I meant to go a bit longer but I reached that point where moving on was the most compelling option.
The whole region is quite strong in Ha, and very faint in SII and OIII.

There is quite a bit going on in this image,the framing was chosen this way on purpose to try and capture the three following objects in one scene

- Sh2-115 at the center of the image is an emission nebula that was catalogued by S. Sharpless in 1959 and lies around 7500 light years away. The core of this nebula has intricate details where all the elements captured with the narrowband filters are mixed, and it has an area rich in OIII that can be emphasized in post processing (here in blue color)

- Sh2-112 on the lower left of the image is an emission nebula with a very interesting shape and color gradation. It lies around 5600 light years from home

- Abell 71 (or Sh2-116, center-right) has been catalogued as a planetary nebula for a long time, resembling a typical PN with a core rich in OIII with surrounding Ha. Latest research shows this to be an HII region

Processing

This image was processed entirely in PixInsight

Preprocessing

- Mure Denoise on all 3 channels
- Dynamic Crop
- DBE
- MLT on background to reduce noise
- Copy original Ha as Luminance and run deconvolution with star mask to bring out detail
- LinearStarnet script on all thre channels to separate stars and nebulosity
- CloneStamp on a couple of artifacts in OIII image

Processing
- Stretch Luminance with HT and curves, and sharpen with MMT (with mask applied)
- Stretch each channel separately with HT and curves, applying masks to emphasize the nebula
- Combine all channels through PixelMath with SHO palette (S-red, H-green, O-blue)
- A ton of curves to manipulate color balance, hue and saturation
- Combine with Luminance through LRGB process, reducing noise in Chrominance
- TGV Denoise + Dark Structure enhance script to emphasize dark dust areas
- Save as PNG

The original version is an HOO combination, could not decide which to publish but I'm going with the more subdued SHO version