Processing advice please

[carastro]

A great result Ags

[ollypenrice]

Excellent.

[Vroobel]

Really, very nice! I have to try any trick with masks in the PI as a substitute of the layers. 

BTW, I used GradientCorrection in PI. It doesn't require any samples for the background modelling. According to original tutorials from PI, after a few steps I reached an even background across a whole image. 

[wimvb]

1 hour ago, Ags said:

OK, here is take three. I did three layers - one for the out shells, one for the core, and one for the stars. In terms of progress, there are less stars and those that are there are less ugly. The outer shell is more defined and smoother, and there is more definition and color in the core.

Excellent!

[ollypenrice]

Sorry but this one really got under my skin! It dawned on me to go back to a kind of aggressive opening stretch which I use on Ha.

This gives the best separation between background and faint nebulosity because of the near-vertical curve at the bottom. You have to deal with the over exposed parts later. I found this let me get the outer shells out of the background. By the time this layer was done the core was almost saturated out.

I then did a regular stretch just for the core. In Ps you can paste the core image on top the extensions image, add a layer mask, paste the over exposed image onto the mask,  blur it, increase its contrast and get a seamless (?) blend of the two.

I've toned down the green this time and replaced stars at the end.

Olly

 

[Ags]

Beautiful Olly!

I know 5 hours of subs is not a lot for Bortle 8 skies (and relatively broad-banded ZWO Duo filter), but it's great to see confirmation there is something viable in the data after all!

[ollypenrice]

16 minutes ago, Ags said:

 

I know 5 hours of subs is not a lot for Bortle 8 skies (and relatively broad-banded ZWO Duo filter), but it's great to see confirmation there is something viable in the data after all!

Exactly. This was one of the things I found captivating in your data. In the not very distant past those shells required hours and hours of Ha and the same again in OIII. And here, dammit, you have all this in five hours of OSC!!! 👌 Incredible. I think it comes from both new cameras and new processing tools.

Olly

[Ags]

I think one of the biggest 'new tool' contributions comes from GraxPert denoising, it really helps tremendously with the background noise from light pollution etc.

I look at what you produced and really doubt whether a cooled camera is going to give me much more. A larger sensor without amp glow would clearly be beneficial, but not so sure of the cooling aspect. 

[wimvb]

Just now, ollypenrice said:

both new cameras and new processing tools

Like I said before, new cmos cameras are changing the rules. Even LRGB is not necessarily better than OSC anymore. My next camera may very well be an uncooled cmos.

In this image, the shell was extremely close to the background, and it could do with some 10 hours more. But the shells are definitely there.

[Ags]

Agreed, I will carry on with this over the summer. With the AsiAir it is is easy to plan a few targets in one session, so I'll add a little to M27 each clear night. 

Another thing that amazes me is my whole setup can be carried as a unit outside without any trouble at all (I'm not particularly strong) and can be perfectly polar aligned in just a couple of minutes, and then I am imaging at about 1000 mm FL at 0.6-0.7" guiding.

[wimvb]

9 minutes ago, Ags said:

Another thing that amazes me is my whole setup can be carried as a unit outside without any trouble at all (I'm not particularly strong) and can be perfectly polar aligned in just a couple of minutes, and then I am imaging at about 1000 mm FL at 0.6-0.7" guiding.

Astrophotography is getting too easy. 😉😉

Seriously though, enjoy your nights under the stars. Ever since astro darkness ended here in Sweden, we’ve had clear nights. Mostly, at least; last night was an exception (image taken at 3 am)

[LuckieEddie]

Late to the game, but here's my attempt on the data using only StarTools.

[Ags]

@wimvb @ollypenrice I took note of your scepticism of GHS stretches, so I had another go in Gimp (rather than doing the stretches in Siril). At first tried two stretches for the nebula merged with a layer mask but I couldn't get that to work in Gimp (still something to learn I suppose) so I tried a single stretch for all parts of the nebula. Stars were processed separately in another layer, and I brought in more stars than the last version, and also tightened the stars a little with Value Propagate.  

 

Edited June 21 by Ags

[ollypenrice]

10 hours ago, Ags said:

At first tried two stretches for the nebula merged with a layer mask but I couldn't get that to work in Gimp (still something to learn I suppose)

Great result, especially for a one-layer stretch.

It's worth getting to the bottom of layer masking, though. The principle is simple: we want to blend a partially saturated image (called S) with a partially underexposed one (called U).

If we make U a top layer over S, we want the over exposed parts of S to be replaced by the correctly exposed parts of U.  We can copy and paste S onto a layer mask for the top layer so the top layer will only be allowed through where the layer mask is white, meaning over exposed. In reality some modification to the layer mask will make it work better. A big increase in the mask's contrast (using an S curve and clipping both the black and the white points to make them totally opaque and transparent respectively) will combine all of the best parts of both layers. A substantial blur of the mask also makes for a smoother transition and removes newly created noise. (Gaussian blur of 1 to 3 but experiment.)

If you keep this principle in mind I'm sure GIMP will allow you to do it. It just works so sweetly!

Olly

Edited June 22 by ollypenrice
typo

[tomato]

On 21/06/2024 at 09:26, wimvb said:

Astrophotography is getting too easy. 😉😉

Seriously though, enjoy your nights under the stars. Ever since astro darkness ended here in Sweden, we’ve had clear nights. Mostly, at least; last night was an exception (image taken at 3 am)

 

Yes, I really do think AP is much easier than say 5 years ago. Hassle free imaging is available at affordable prices with the advent of the Seestar and Dwarflab and the AI based processing tools can turn sow’s ear data into silk purse images. Is it still fun? You bet!

 

 

 

 

[Ags]

3 hours ago, tomato said:

sow’s ear data

Oy! Nothing wrong with my data!!! 😃

[Ags]

I got another hour last night on M27, and then an hour and a bit on the Veil. The next two nights are good for imaging, but they are work nights so I will only be able to add a couple more hours.

[tomato]

15 hours ago, Ags said:

Oy! Nothing wrong with my data!!! 😃

 You should see my F2 imaging corner stars, I should send Russell Croman  a Christmas card.

[gonzostar]

On 22/06/2024 at 08:52, ollypenrice said:

Great result, especially for a one-layer stretch.

It's worth getting to the bottom of layer masking, though. The principle is simple: we want to blend a partially saturated image (called S) with a partially underexposed one (called U).

If we make U a top layer over S, we want the over exposed parts of S to be replaced by the correctly exposed parts of U.  We can copy and paste S onto a layer mask for the top layer so the top layer will only be allowed through where the layer mask is white, meaning over exposed. In reality some modification to the layer mask will make it work better. A big increase in the mask's contrast (using an S curve and clipping both the black and the white points to make them totally opaque and transparent respectively) will combine all of the best parts of both layers. A substantial blur of the mask also makes for a smoother transition and removes newly created noise. (Gaussian blur of 1 to 3 but experiment.)

If you keep this principle in mind I'm sure GIMP will allow you to do it. It just works so sweetly!

Olly

Hi

Is this the same technique you could use as if Processing M42 as to get the core and fainter nebula with photoshop? l am also having a go at processing M27. Amazed by everyone's effort getting the faintness of the dumbbell. 

 

Cheers

Dean

[ollypenrice]

24 minutes ago, gonzostar said:

Hi

Is this the same technique you could use as if Processing M42 as to get the core and fainter nebula with photoshop? l am also having a go at processing M27. Amazed by everyone's effort getting the faintness of the dumbbell. 

 

Cheers

Dean

It is indeed. As things stand there is still no hope of revealing the dynamic range of M42 in a single stretch.  (Stands back to be proven wrong! )

Olly

[gonzostar]

8 minutes ago, ollypenrice said:

It is indeed. As things stand there is still no hope of revealing the dynamic range of M42 in a single stretch.  (Stands back to be proven wrong! )

Olly

Thanks Olly, That's  a challenge way beyond my capabilities 😁

[ollypenrice]

4 minutes ago, gonzostar said:

Thanks Olly, That's  a challenge way beyond my capabilities 😁

No, honestly, it's not. When I learned how to do this I was close to computer illiterate. I followed this explanation by that very nice man, Mr Jerry Lodigruss.

https://www.astropix.com/html/processing/laymask.html

The tutorial is as relevant today as it was over 10 years ago. Try it!

Olly

[gonzostar]

11 minutes ago, ollypenrice said:

No, honestly, it's not. When I learned how to do this I was close to computer illiterate. I followed this explanation by that very nice man, Mr Jerry Lodigruss.

https://www.astropix.com/html/processing/laymask.html

The tutorial is as relevant today as it was over 10 years ago. Try it!

Olly

Thankyou for this very useful. Also following @carastro youtube clip. Between you I will get a decent M27 also 👍

[gonzostar]

On 20/06/2024 at 13:02, carastro said:

I had forgotten that.  All credit goes to Olly for this though as he taught me this method and we agreed I could post it on You Tube.

It should be here but for somesoI can't personally connect to You Tube at the moment, keeps tells me I am not connected to the Internet, but I clearly am or I couldnt post this.  

https://www.youtube.com/watch?v=xpPvENVdwjs 

 

Thankyou Carole, Following your youtube clip to get the fainter bits of M27

[Rallemikken]

On 20/06/2024 at 15:57, wimvb said:

My version.

That's impressive! We're talking 1.2 MP here. How would this look without BlurXtermiinator? I've been fiddling with Siril and Gimp an hour by now, not even close! Especially the stars, can't get them that well defined. And those spikes; love it!