Jump to content

M16 - Eagle Nebula


Recommended Posts

5 minutes ago, paulgrover68 said:

Last night was only meant to be about equipment testing - I've reconfigured the 130's rig a little and 72EDF a lot.  72EDF still needs a few bits.

This was on the 130. I used every minute of the 2 hours of fake darkness to grab this... 32 x 240 second exposures.  If next weekend is clear I'll add some more data.

I must sort a rotator for the big scope, as it;s not framed as I would ideally like. May have over processed a bit... out of practice
 

M16 - The Eagle Nebula

 

 

Looks great for just a couple of hours. I wouldn't say it's over processed, the details are nice and sharp. Maybe the stars are a little saturated, but that is an easy fix.
 

Brian

  • Like 1
Link to comment
Share on other sites

4 hours ago, AstronomyUkraine said:

 

Looks great for just a couple of hours. I wouldn't say it's over processed, the details are nice and sharp. Maybe the stars are a little saturated, but that is an easy fix.
 

Brian

I've been leaning a bit heavily on the StarShrink plug. While stuck in a traffic jam I realised I'm pushing the curves up and then expecting the plug in to pull them back - which is a bit silly.

 

So I just went back and had a go at creating a star mask in photoshop - result was a pretty good. I use a far less aggresive star shrink and stuff it works quite well.

Saturated and bloated stars are my current nemesis - any suggestions very welcome as my success in dealing with them has been hit and miss.

I've also been without data for so long I need to slow down my processing - I'm rushing through actions just to get an image and inevitably I find myself going back and starting over!

 

  • Like 1
Link to comment
Share on other sites

27 minutes ago, paulgrover68 said:

I've been leaning a bit heavily on the StarShrink plug. While stuck in a traffic jam I realised I'm pushing the curves up and then expecting the plug in to pull them back - which is a bit silly.

 

So I just went back and had a go at creating a star mask in photoshop - result was a pretty good. I use a far less aggresive star shrink and stuff it works quite well.

Saturated and bloated stars are my current nemesis - any suggestions very welcome as my success in dealing with them has been hit and miss.

I've also been without data for so long I need to slow down my processing - I'm rushing through actions just to get an image and inevitably I find myself going back and starting over!

 

The best tool to avoid oversaturating your stars is Starnet++. Use it on your stack just before it's fully stretched, then reintroduce the stars after stretching and colour correction. I don't use Photoshop for processing astro images. Photoshop users on here probably have other methods to avoid bloated stars, this is the process I use in Pixinsight.

Edited by AstronomyUkraine
  • Like 1
Link to comment
Share on other sites

Nice image Paul. As you found out, star masks in PS help. 
 

Just googled images of Sinclair’s ZX81 after seeing your kit list. That was a blast from the past. 

  • Like 1
Link to comment
Share on other sites

46 minutes ago, David said:

Nice image Paul. As you found out, star masks in PS help. 
 

Just googled images of Sinclair’s ZX81 after seeing your kit list. That was a blast from the past. 

The dreaded RAM pack wobble - usually after you'd spent a whole day of the summer holidays typing in the game code from a listing in Computer & Video Games magazine

Link to comment
Share on other sites

46 minutes ago, paulgrover68 said:

The dreaded RAM pack wobble - usually after you'd spent a whole day of the summer holidays typing in the game code from a listing in Computer & Video Games magazine

I vero-wrapped my own home brew 64kb RAM pack and soldered it in to the expansion connector  - no wobble!

  • Like 1
Link to comment
Share on other sites

Haha I too laughed at the ZX81 reference. I had (still have) a ZX Spectrum in the loft along with 2 Sinclair QL's. I just can't bare to part with them. They probably don't work now though.

  • Like 1
Link to comment
Share on other sites

I decided to pursue the Starnet ++ route.  I had some issues on my Mac, so had my PC do the work.  This actually worked well as I could do other stuff while the stars were removed.

This result is far from perfect - I have some halos and more artefacts than the V & A.  I can see is how powerful this is and I'm encouraged to experiment more.  I included the starless image here just for reference (it shows some of the oddities).  I think much of this is due to working with an image I'd already applied a lot of processing to (notably starshrink) I will do a from scratch process on this or my next set of data.
 

M16 with fixed stars

 

and the interim starless version

 

m16-starless

 

I probably would not have experimented with this had it not been for this thread - so many thanks. I still have much to learn, but it's not a chore to learn it.

  • Like 3
Link to comment
Share on other sites

56 minutes ago, paulgrover68 said:

I probably would not have experimented with this had it not been for this thread - so many thanks. I still have much to learn, but it's not a chore to learn it.

The trick to get the most out of Starnet++ is to remove the leftover halos and artifacts, before reintegrating the stars. The best method is by using the clone stamp tool set to a low opacity, around 10% works well. Set the radius to the approximate size of the artifact, and sample close to the artifact to remove it. It a laborious job, but the results are well worth it.

 

  • Like 2
Link to comment
Share on other sites

19 minutes ago, paulgrover68 said:

Excellent - I figured that might be a possibility. I was initially fooling with layer mask on the dark areas to mask them out.  That'll be my homework for tomorrow!

Forgot to say. I only mentioned the clone stamp tool for removing artifacts, because that the only tool available in Pixinsight for removing artifacts. In Photoshop you have a variety of different tools that might work better than the clone stamp.

Link to comment
Share on other sites

I do this in Gimp and I like the Heal tool. After stacking and a very light stretch, apply starnet++ to extract the starless image. Subtract this in Gimp/PS from the original to isolate the star field. Stretch and process the starless as you see fit, including cloning/stamping/healing the artefacts out, and merge the stars back on top with 'lighten only' blend mode.

 

I sometimes also apply the stars a second time in 'normal' mode. If the stars are slightly saturated, this can 'fill in' the cores, reduce the halos, and make them look a little more natural overall. It's useful if you have a natural colour halo, with a white saturated core.

Link to comment
Share on other sites

Beautiful.  I prefer your first version with the stars though.  Really sharp and crisp.  Was that with the ASI294MC Pro?  I have just bought the mono version.

Edited by Gina
  • Like 1
Link to comment
Share on other sites

2 hours ago, Gina said:

Beautiful.  I prefer your first version with the stars though.  Really sharp and crisp.  Was that with the ASI294MC Pro?  I have just bought the mono version.

Yes this was the 294MC-Pro. I've had it about a year now and no complaints.  When I go mono I'll probably go with the mono version as the sensor matches well with my scopes.


 

Link to comment
Share on other sites

1 hour ago, MarkAR said:

Very good result for a test run.

I was genuinely surprised by how good it came "out of the box"  I've since reprocessed some old data and results have been a little mixed. There are definitly more I need to learn on this.  What's encouraging I'm seeing a path from where I am to where I want to be next... just haven't quite worked out the route yet...

Link to comment
Share on other sites

1 hour ago, paulgrover68 said:

I was genuinely surprised by how good it came "out of the box"  I've since reprocessed some old data and results have been a little mixed. There are definitly more I need to learn on this.  What's encouraging I'm seeing a path from where I am to where I want to be next... just haven't quite worked out the route yet...

Practice practice practice.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...