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Rosette nebula

P Holdsworth

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I like the colour palette you have applied to your Rosette, however the black point has been brought up too much into the left of the histogram..

There is nebulousity detail out on the edges of the Rosette as it sits in a large molecular cloud of interstellar dust and gas. 


Teasing out that detail as it sits on the boundary of noise is challenging so that the main image does not get 'blown out'.

As a suggestion and opportunity to try out something new in your processing flows,  there is a  new stretch utility that can be added into PI, Generalised Hyperbolic Stretching, it allows you to set a 'focus point' on the histogram where you want to apply most stretching and you can protect highlights in the same process.


I have been using it recently and although it has more parameters to adjust before a stretch is made I think it helps extract the best dynamic range in the image data from the faint dark nebulousity to the bright radiated glows. There are threads discussing GHS on other forums and a specific thread on Pixinsight forum.  https://pixinsight.com/forum/index.php?threads/generalised-hyperbolic-stretching-revisited.17658/

There is also a video of a zoom meeting on one of these threads, cant recall which one at the moment, where the developer talks a US astroimager through the stretch process - its a bit tedious to watch, but does  cover the basics in how to use the tool.

As you say the weather over next few days is looking grim so an opportunity to try out some new processes while the wind blows

Hope you find this useful,



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