M42 – Orion Nebula – one year later

 Update! I’ve reprocessed the image:

m42_HDR_latest

The steps were mostly the same as before, but the HDR stage was tweaked a bit:

  • RGBWorkingSpace changed to 1 for each channel
  • DynamicPSF to generate PSF for Deconvolution
  • Luminance mask created from RGB image
  • Deconvolution used to bring out some more details
  • Multiple HistrogramTransformation runs to stretch the image carefully, and align the channels
  • HDRMultiscaleTransform with the brightest stars masked, once on the larger scale (~10) and once on a smaller scale (~7)
  • SCNR to reduce green
  • ACDNR to reduce noise
  • HistogramTransformation to stretch the image a little further
  • RangeMask+StarMask used to protect the background & bright stars
  • LocalHistrogramEqualisation used on the nebula to brighten things up
  • CurvesTransformation to increase contrast
  • UnsharpMask to sharpen some details slightly
  • Slight Convolution to reduce a bit of the harshness from UnsharpMask
  • ColourSaturation three times, one with a mask protecting everything but the brightest stars, one protecting the background and bright stars to increase saturation on the nebula, and once with the previous mask inverted to reveal some colour in the dusty background.
Original post:

m42-HDR

I’ve shot this target before!

I haven’t done a HDR shot before, most targets don’t really need it in my experience. There is one huge exception – M42! The core of M42 is super bright compared to the rest, and then there’s the dust which usually goes unseen until you take much longer exposures.

M42 is easy to capture, hard to master.

General Details:
  • Date taken: 14/12/2014
  • Location: Adelaide, South Australia
  • Camera: Canon 450d w/ IR filter removed, GSO coma corrector
  • ISO800
  • Mount: HEQ5PRO
  • Scope: GSO 8″ f/5 Newtonian
  • Autoguider: Orion Starshoot AG
  • Imaging: BackyardEOS w/ PHD dithering
  • Guiding: PHD2
  • 50 bias frames, 20 dark frames (for the 300 second lights only!), 50 flat frames
  • 15 x 10 second exposures
  • 15 x 60 second exposures
  • 12 x 300 second exposures
  • Total integration time: 4650 seconds
Pre-Processing details (performed on each exposure length individually):
  • BatchPreProcessing, calibration only
  • BatchDebayer
  • Star Alignment with drizzle (took a lot of tweaking to get the 10 second exposures to align correctly!)
  • Blink to check for and remove any bad frames
  • Image integration with drizzle (using Winsorized Sigma Clipping)
  • Automatic background extraction on the three integrated RGB images to remove the light pollution
Processing the resulting RGB Images:
  • BackgroundNeutralization
  • ColourCalibration
  • SCNR to remove the green tinge
Prep the images for HDR:
  • StarAlignment of the three different integrations so they’ll line up
  • Blink to make sure they are lined up OK
  • DynamicCrop to cut out any bad edge bits
HDR Time:
  • HDRComposition to combine the three different exposure length integrations
  • RGBWorkingSpace
  • ACDNR to reduce noise
  • HistogramTransformation x2 to bring out the background dust
  • HDRMultiscaleTransform to reveal the core of M42
  • ColorSaturation to enhance the colours a bit
  • CurvesTransformation to enhance contrast and luminance
  • LocalHistogramEqualisation to brighten the image a bit

M8 – Lagoon Nebula – Take 3

m8-reprocessed

I have re-used the data from my previous attempt, this time the processing was done entirely in PixInsight. If I recall correctly, there was 10 light frames used for a total integration time of 50 minutes.

  • Date taken: 14/08/2014
  • Location: Adelaide, South Australia
  • Camera: Canon 450d w/ IR filter removed, GSO coma corrector
  • ISO800
  • Mount: HEQ5PRO
  • Scope: GSO 8″ f/5 Newtonian
  • Autoguider: Orion Starshoot AG
  • Imaging: BackyardEOS w/ PHD dithering
  • Guiding: PHD2

The colour calibration is much more accurate this time around. I have also managed to reduce the noise considerably during the integration phase by using Winsorized Sigma Clipping. This allowed me to be a lot less aggressive with the noise removal tools, resulting in a more defined image.

M8 – Lagoon Nebula – Take 2

m8-august

Nine 5 minute frames stacked using DeepSkyStacker, processed using PixInsight

  • Date: 14/08/2014
  • Location: Adelaide, South Australia
  • Camera: Canon 450d w/ IR filter removed, GSO coma corrector
  • ISO800
  • Mount: HEQ5PRO
  • Scope: GSO 8″ f/5 Newtonian
  • Autoguider: Orion Starshoot AG
  • Imaging: BackyardEOS w/ PHD dithering
  • Guiding: PHD2

I’ve shot this target before, but this time I’m using a coma corrector. If you compare this shot with the previous one, it’s upside down! This is because my first attempt was done when M8 was quite low in the eastern sky, whereas this time it had passed the meridian and the mount has gone through a meridian flip.

I also did noise reduction in PixInsight using a relatively new tool called TGVDenoise, it takes a bit of trial and error but the results are great!

M8 – Lagoon Nebula

Six 5 minute frames stacked using DeepSkyStacker & Photoshop.

  • Date: 23/05/2014
  • Location: Adelaide, South Australia
  • Camera: Canon 450d, modded with IR filter removed
  • Mount: HEQ5PRO
  • Scope: GSO 8″ f/5 Newtonian
  • Autoguider: Orion Starshoot AG

m8-lagoon

I then tried playing with the image using PixInsight to see if I could make it look any better:

lagoon-1920-reprocessed