Night Sky Panorama Workflow

Processing
1

Hello!

Last night I was out with a friend and did my first real Milkyway shots. I’ve did a panorama and I need some help how to process it. I can’t develop the RAW files right now, as my new camera isn’t supported yet. I hope that will change soon.

Steps for processing

RAW

  • Fix chromatic aberrations
  • Demosaic
  • Denoise the pictures (3 step denoise with denoise profiled)
  • Export to TIFF

Hugin

  • Stitch everything
  • Crop

TIFF

  • Defringe stars
  • Enhance milkyway
  • Enhance foreground

If I want to work on the foreground for example do some tone mapping, do I work on the RAW or stitched TIFF? What other things do I need to do in RAW before I stitch them?

I will try to update that post and maybe we could make an article out of it.

2

I try and do as many operations as possible on the raw file because there is more data to work with there than in the tiff file after you’ve processed. That way, all you’ll have to do post-stitch is clean up stitching artifacts, if any.

Are you doing any stacking or just stitching?

3

Only stitching.

I will then play around with it and try to write down what I did here, maybe it helps someone else too.

4

Any hugin help would be much appreciated by me, I like the application, but I am not skilled in using it :smile:

5

Paging @Jonas_Wagner

1 Like
6

I usually use Rawtherapee for processing my astro raws. They have a few nice features for that like darkframe subtraction and LMMSE / IGV demosaicing which works well for higher noise images.

I usually apply fairly little processing to the raws and then go into 16bit tiff. I don’t have my presets around at the moment but it’s usually demosaicing with either LMMSE or IGV, lens corrections (CA, vignette, distortion) and some basic exposure adjustments, white balance, a slight boost in saturation and denoising. If you sharpen at this stage be sure you exclude noise using a threshold. Go lightly on the exposure or you will lose the relative brightness differences between stars. Go light on the denoising or you will lose fainter stars, details in nebulas and the colors of the stars. Stacking or stitching + downscaling will make most of the noise go away at later stages.

Avoid applying non local adjustments (like tone mapping) at this stage otherwise you will create artifacts at the boundaries.

Then I stitch in hugin and afterwards I would process the image in either GIMP (mostly using G’MIC) or DT.
This is where I would apply non local edits, some additional more targeted denoising, curves and sharpening.

Milkyway season is coming along again around here so I think it will be time for some videos and play raws I guess. :slight_smile:

7

Which of the features are missing for you in DT?

8

LMMSE/IGV, dark frames/flat fields, if I recall correctly I have some lens profiles for RT but not for lensfun/DT. For the A6000 I think there is a profile in RT but not in DT (and mine didn’t quite turn out right, need to reshoot it). I might have forgotten some additional reasons but in the end it’s all details. Using DT would absolutely be possible.