how to use the lens module now that colour comes much later?

Questions and answers about problems with the software, modules or functionality.
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almcl
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Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

how to use the lens module now that colour comes much later?

Post by almcl »

Been processing my first ever bi-colour image and, perhaps due to slightly misaligned stacking in DSS and slight rotation of camera between filters, the blue and red bits don't quite line up.

Previously I would try and sort this using the Red/Blue X and Y shift in the Lens module, but aside from not being able to see the colours now at the early stages of processing (which I believe is where the lens module works best) I don't seem able to move the blue and red channels relative to each other.

Anyone else met with this?

Here's a blow up of an area of the image:
red_blue shift.jpg
red_blue shift.jpg (40.88 KiB) Viewed 1448 times
Skywatcher 190MN, astro modded Canon 700d, cls ccd, or Ha or Oiii filters, guided by OAG, ASI120, PHD2
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admin
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Re: how to use the lens module now that colour comes much la

Post by admin »

First off, would there be any way to fix this while stacking? (e.g. if using DSS, try "Align RGB Channels")

Second, remember that - thanks to Tracking - you can use the Restore functionality to restore the dataset to its linear ("original") state at any time with some operations intact (e.g. Crops, Wipes, and Lens shifts).
Just like you can use the Restore functionality in combination with AutoDev and Wipe to see what you're doing, you can also use the Restore functionality in combination with AutoDev+Color to see what you're doing when using the Lens module, then Restore the dataset to its 'Original' state.

So to recap;
  • AutoDev to see what you're doing
  • Wipe if you need to to see the color changes
  • Color
  • Lens
  • Then Restore to Original state
  • Now process your fixed up dataset as normal
Any trouble, let me know!
Ivo Jager
StarTools creator and astronomy enthusiast
almcl
Posts: 157
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: how to use the lens module now that colour comes much la

Post by almcl »

Thanks, as always, Ivo.

I tried to get DSS to stack with color alignment but it didn't make any discernible difference.

However, when reprocessing I used the duotone tab in the color module and things improved quite a bit. In the (heavily cropped and expanded) image below, the original, misaligned, image is on the left and the one using duotone is on the right.

They were processed slightly differently, but the colour fringing has gone almost completely!
side by side.jpg
side by side.jpg (36.03 KiB) Viewed 1418 times
I think the overall result (again, cropped and reduced) is better as well:
NewComposite3.jpg
NewComposite3.jpg (88.04 KiB) Viewed 1418 times
Skywatcher 190MN, astro modded Canon 700d, cls ccd, or Ha or Oiii filters, guided by OAG, ASI120, PHD2
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Re: how to use the lens module now that colour comes much la

Post by admin »

That's a lovely Veil Nebula! :thumbsup:
The Duoband preset button uses rather aggressive desaturation settings, in combination with the "Artistic, Not Detail Aware" style which also progressively desaturates colouring in the highlights.
All up, this keeps the Color module from trying to recover colouring in the highlights. It's definitely helping here!
Ivo Jager
StarTools creator and astronomy enthusiast
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