M42, the Orion Nebula

28 December, 2023
revision mono broadband nebula

Acquisition Details

M42 Lum. Red Green Blue
Frames 28 17 16 16
Exp. Time 30s 120s 120s 120s
Darks Master      

Final Masters

L, 300s

Update: 28 Dec 23

Removing flat frames

After almost a year I’ve updated the M42 image with another revision of the same data. I ditched the flat frames since these where taken with a way too short exposure time creating bands of read noise. The ideal exposure time for flat frames is 3+ sec for astro cameras.

Adding High Dynamic Range (HDR)

I’d taken 30 sec exposures as well so I decided to try and test out the HDR workflow. This includes a combination of both HDRComposition (for merging the two luminance images masters to a high dynamic range image) and the HDRMultiscaleTransform.

A great workflow of creating HDR images in PixInsight can be seen on the video below:

PixInsight Wokflows: instructions on how to process images as HDR


Another run on M42 after a full strip down of the HEQ5 Pro and applying some thorough maintenance. Shot this new footage of M42 together with some new flat frames since my master flat frame had some banding issues. Luckily this could be fixed easily by making new ones with longer exposures.

Maybe time for an Hα-filter? 🙃

The image below shows a high contrast visual of the annotated M42.

M42 Inversed, high contrast

Astrometry Calibration

Astrometry Job 7292529
Center (Dec, dms) -05° 17’ 31.781”
Center (RA, Dec) (83.785, -5.292)
Center (RA, hms) 05h 35m 08.351s
Pixel Scale 1.56 arcsec/pixel
Radius 1.694 deg
Size 2.39 x 2.4 deg

Data Processing

Processing was done in PixInsight only. Steps of the process are listed below:

  1. Weighted Batch PreProcessing,
  2. DynamicBackgroundExtraction,
  3. ChannelCombination,
  4. ImageSolver,
  5. PhotometricColorCalibration with background neutralization,
  6. BackgroundNeutralization,
  7. HistogramTransformation,
  8. Masked appliance of NoiseXTerminator and BlurXTerminator.
  9. Final adjustments (LRGB merging color and saturation) done in in Photoshop.