My Workflow for Comet Stacking

This is my shot of the Atlas comet from back on 11th April. My workflow steps to create it were:

  1. Capture data- 90 x 1 min L, 15 x 1 min each RGB using SW200p.
  2. Realise that I don’t know how to stack comet data and leave for 2 weeks.
  3. Try and stack using PI but find that Pixinsight Comet Alignment won’t stack DSS calibrated FITS files. Swear. Leave for another 2 weeks.
  4. Relearn how to calibrate in PI and start processing only to discover all subs are slightly out of focus and quite a few are spoilt by cloud.
  5. Reduced to 28 mins of RGB frames and stack to create the starfield- stars are OK but the comet is a disco smear (unsurprisingly).
  6. Use the PixInsight comet alignment tool on the L data. Looks completely pants. Swear again, delete it and give up.
  7. A couple of days later remember that DSS has a Comet alignment tool in it. Bit of a faf (you have to tell it where the comet is in each frame) but gave a much better result.
  8. Use GIMP to clone and blur out the worst of the stacking artefacts and layer into the starfield in lighten mode.

So- here it is, plus a few “making of” shots. It feels like I’ve cheated a bit as this is a mono comet with RGB stars, but after the difficulties in processing it I’m actually really pleased to have got something!

The Disco Comet:

The DSS Comet:

Put it all together:



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