This wide field image of the central region of the Orion constellation was captured on the nights of January 20/21/25/29 and February 2, 2020 using a short telephoto lens and dual narrowband filter. As is the case for many of us, this was one of my first deep sky astrophotography targets and remains a perennial favorite. I captured images at two different exposure durations (30 s and 240 s) to generate HDR images capturing both faint nebulocity and a bit more detail in the core of M42. This is image includes both the H-alpha data (red channel) and OIII data (green & blue channels) combined using the HOO palette..

Imaged with 85mm/F1.4 Rokinon at F/2, STC Duo Narrowband Clip Filter, and full spectrum modified Nikon D5300.

Pre-processed using PixInsight Batch Pre-Processing (BPP) script. Images calibrated using darks, bias, and flats. Extracted red/green/blue channels using BatchChannelExtraction script. R, G, & B channels registered and stacked independently using StarAlighment and Integration. R channel data gives the Ha image. Averaged G & B channels using Pixelmath to generate OIII image.

For the long exposures, total integration time of ~4 hours using 68 subs at ISO200 x 240 sec.

For the long exposures, total integration time of ~1 hour using 51 subs at ISO200 x 30 sec.

R and Average of G+B channels individually post-processed in Pixinsight: Cropped, gradient removal with ABE, HDRComposition (binarizing threshold = 0.6) to combine different exposure lengths, MLT for noise reduction, stretched using masked stretch, Curves Transformation, TGVDenoise for noise reduction, HDR transform, Local histogram transform, morphological transform to shrink stars.

HOO image generated using SHO-AIP script with luminance using Ha data. Additional post-processing of the HOO image included photometric color calibration and color saturation adjustment.

For Ha version of the image and additional acquisition details, see: https://astrob.in/16f0kh/0/