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Pixinsight with film images

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#1 Joe F Gafford

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Posted 08 November 2019 - 06:12 PM

Here's an example of using Pixinsight on your film images. This was a piggy-backed Olympus OM-1 camera on my then stock Meade 10" Newtonian. Taken on 7-19-1987 at the cabin near Kenosha Pass, CO. 50 mm lens at F/1.8. Kodak VR 400 print film, 8 minute exposure of the Big Dipper. Before image is scanned 16 bit and cleaned of motes. The second image went through the PI ABE (Automatic Brightness Extraction) and sent back to Photoshop to be further brightness curves adjusted. This gets rid of the vignetting effects. Also with odd gradients as well. 

 

UMa_ABE_7_19_1987_Demo_web.jpg

 

The gradient profile.

UMaAa_ABE_background.jpg

 

Joe


Edited by Joe F Gafford, 08 November 2019 - 06:15 PM.

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#2 TxStars

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Posted 09 November 2019 - 04:59 PM

I like how the background has darkened, to me this looks really good..



#3 Michal1

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Posted 09 November 2019 - 06:58 PM

I was trying for this years ago, too. I even described my method here in this forum. I eventually realized that I prefer having the vignetted background in this type of images, without dense star fields or extended nebulae. Removing vignetting from images of the Milky Way is difficult. There is often no area that would be really empty. I have two favorite methods for these cases -- neither of them is perfect. The first is an unsharp masking with a very large radius, larger than the structures in the Milky Way. The other, the more reliable but also the more laborious, is the combination of the lasso tool, curves/levels and my feeling for how the sky should look like :) .


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