Starnet++ experiments.

[ollypenrice]

My stepson Sasha, an IT professional, took about 10 seconds to get Starnet++ working in PI after I'd spent an eternity failing. (It' s a star removal routine.) I've now tried three ways of removing stars, my own simple one, Straton and Starnet. Starnet wins and is free and 'one click' to use. Narrowband imagers wanting to remove stars entirely will want a perfect result. I don't need that because some residual starry presence will be covered when I replace the stars with less stretched ones in my broadband images. Below is the 'Gamma Cass and Breaking Wave to Pacman' image Tom and I did a while ago. On the left the stars are as small as I could get them without using the 'remove and replace' method. On the right is the result of removing them with Starnet, giving the nebulosity one tiny extra push, and then replacing the left hand image's stars at partial opacity.

Honest preferences: what's your feeling?

 

[Magnum]

There are some black cores to some of the stars on the left image Olly.

edit, actually the right image has them also but not as dark

Lee

Edited June 8, 2020 by Magnum

[tooth_dr]

I don’t mind stars, so for me it’s probably the one of the left.  But I’m viewing on my phone so that viewpoint might change when I’m on my pc later. 

[tomato]

I like stars, but for sure the detail in the nebulosity is not competing so much for your attention in the RH image. 
 

So, trying to assess the impact on the whole image, the RH one gets my vote.

[steppenwolf]

On this occasion, I prefer the image on the left but for other images, I know that the reduced star size can have a very beneficial effect. On a relatively wide field image like this, I feel that the smaller stars look too much like 'dust'. I like Starnet ++ and I agree with Olly, it is the best of the tools out there to carry out this task.

[ollypenrice]

1 hour ago, Magnum said:

There are some black cores to some of the stars on the left image Olly.

edit, actually the right image has them also but not as dark

Lee

They're the same stars but, yes, an artefact has crept in. I hadn't noticed, but it isn't present in the TIFF. Ideally I'd not replace the reduced stars, as I did here, but go back to the pure RGB stars and apply those. I'll have a trawl through the old data and see if I can make that work.

Olly

Edited June 8, 2020 by ollypenrice

[fwm891]

Like the righthand image as the nebulosity stands out more. But I think it could edge just a touch to the left without impacting on the nebulae...

[Kinch]

Looking at an area like this -the image on the left looks far more natural and to my eyes - a better image overall. 

When looking closer in at a nebula, then at times, a good reduction of the stars helps divert attention to the nebula (rather than the stars)- exactly as we want. I use Starnet on occassions to achieve this  - but I do not actually remove stars from my working image to put them in later - but rather use starnet to make my star mask. (Maybe it is the same difference....but I just prefer to work that way!)

 

[Knight of Clear Skies]

To my eye, the starfield looks better on the left but there are details in the nebulosity in the right hand image that can't be seen on the left hand one. I wonder if a colour presentation next to a mono Ha or bicolour to show more detail is the way to go.

Alternatively, put both versions on top of each other on a webpage with a slider to adjust the stars (opacity change).

Edited June 8, 2020 by Knight of Clear Skies

[Laurin Dave]

Your family gathering was clearly a success in more ways than one Olly!   For the stars somewhere slightly to the left of the middle for me ....  for the nebulosity further to the right so maybe be worth seeing what adding a bit of Starnetted Ha to a left of middle version looks like.. 

Couldn't resist a fiddle … It'd be something like this I think  (Red channel from the right one added in blend mode lighten to Red channel in a 70:30 blend of L and R) 

Dave

 

Edited June 8, 2020 by Laurin Dave

[ollypenrice]

4 hours ago, Laurin Dave said:

Your family gathering was clearly a success in more ways than one Olly!   For the stars somewhere slightly to the left of the middle for me ....  for the nebulosity further to the right so maybe be worth seeing what adding a bit of Starnetted Ha to a left of middle version looks like.. 

Couldn't resist a fiddle … It'd be something like this I think  (Red channel from the right one added in blend mode lighten to Red channel in a 70:30 blend of L and R) 

Dave

 

 

Yes, we're in blend-land with these techniques! Left a bit, right a bit... Ten minutes later it's, What was I thinking???

🤣lly

[Tom OD]

Nice work Olly

I think the image on the right should accompany the image on the left, in a manner that allows a better look at the nebula and some structure than is revealed.

So the image on the right is important and on such wide-field areas of the sky it helps bring out all the dust. However as far as a representation of the area goes, I prefer the left image with stars.

Tom

[Tom OD]

By the way Adam Block does a very good tutorial on small and tiny star suppression. It keeps them round, and does not just dim them like some of the PI Morp routines can do. Its great but tricky to get right on areas neat the Milky Way

or images that go very deep. Here is a not so perfect attempt side by side. I know I can do a little better.

Tom

 

[wimvb]

The left image for me. Viewed on my iPhone, the right image seems to have holes where there should be stars. Maybe replace the stars at original strength after you’ve strengthened the nebula?

[carastro]

Unzoomed I prefer the image on the right as it shows more of the Nebula, but zoomed in the one on the left is gorgeous.

Basically can't decide, but in general i do prefer star reduction to allow the nebula to stand out better.

Carole 

[johneta]

I really like minimal stars in my images, but I prefer the left. Stars on the right are not full brightness at the center and look soft.

Ive tried for a while now to work starnet into my workflow but have had mixed results. It is amazing how it works, but I always get too many artifacts with  my final images.