Data Set for Northern Friends

[Rodd]

Its that time of year again.....when the darkness wanes in the far north and imaging must be put on hold for months, I try and keep the fires smoldering by tossing a few logs onto the hearth when I can for a bit of relief from the cold.  This is an LRGB set of the Iris Nebula I collected a while back.  I am still working on the data myself after quite a bit of time.  I collected luminance but ended up not using it as it gave no enhancement to the image.  the stars were off (larger than the RGB stars).  Conditions were not as good, or maybe focus was off a bit.  I decided to include it anyway, and now that I look back, am not sure whether I used it or not.  My Astrobin page said I did, but when I revisited the data for a reprocess I did not like it.  Its here if you want it.  The stacks are fully calibrated and registered.  No additional processing has been done.  

The data was collected with the TOA 130 and ASI 1600mm cool pro with Astrodon Series E Truebalance filters.  Sub length for all filters was 120 sec (a bit over 25 hours).  As always, good luck and have fun

r218.fit

g236.fit

b93.fit

L193.fit

 

Here is my latest version, which is binned 2x2 in software.  The software binning helped with the noisy dust.  I don't think scale has been hurt too badly.  Perhaps a bit over saturated...I am working on it!

 

 

Edited May 8, 2020 by Rodd

[Wyvernp]

Love the Iris nebula, and that is a great image! Just downloading the data now, hope I can do it justice! I am fro southern England though...hope that's ok? 😂

Edited May 8, 2020 by Wyvernp

[Rodd]

11 minutes ago, Wyvernp said:

Love the Iris nebula, and that is a great image! Just downloading the data now, hope I can do it justice! I am fro southern England though...hope that's ok? 😂

I hope so too!  I am sure you will.  Good luck

[Rodd]

Looking forward to seeings Wim’s version

[ollypenrice]

Well, looking at your version doesn't fill me with the conviction that I could do any better! Nice of you to post the data but your rendition is very convincing.

Olly

[teoria_del_big_bang]

12 minutes ago, ollypenrice said:

 your rendition is very convincing.

Olly

It is a beautiful Nebula , your image does it more than justice and for Olly to say it is VERY convincing must make you very happy 🙂 

Steve

[Rodd]

1 hour ago, ollypenrice said:

Well, looking at your version doesn't fill me with the conviction that I could do any better! Nice of you to post the data but your rendition is very convincing.

Olly

Thanks Olly.  It was a long road. As for the data, I don’t know what I would do if I couldn’t image for 3 months.  My heart really goes out to the northfolk.

[Rodd]

1 hour ago, teoria_del_big_bang said:

It is a beautiful Nebula , your image does it more than justice and for Olly to say it is VERY convincing must make you very happy 🙂 

Steve

You’ve no idea!   I am elated.  And thank you for your kind words as well 

[wimvb]

11 hours ago, Rodd said:

Looking forward to seeings Wim’s version

No pressure, of course. Just before grading "season", and end of term activities. (Swedish schools never closed down because of Covid-19.)

[Rodd]

2 minutes ago, wimvb said:

No pressure, of course. Just before grading "season", and end of term activities. (Swedish schools never closed down because of Covid-19.)

What subject do you teach Wim?  

[wimvb]

3 minutes ago, Rodd said:

What subject do you teach Wim?  

Physics & math. My students are aged 12 - 15.

[Rodd]

16 minutes ago, wimvb said:

Physics & math. My students are aged 12 - 15.

Very cool.

[tooth_dr]

31 minutes ago, wimvb said:

Physics & math. My students are aged 12 - 15.

This explains your willingness to help others, and your large amount of patience 😂

[ollypenrice]

11 hours ago, teoria_del_big_bang said:

It is a beautiful Nebula , your image does it more than justice and for Olly to say it is VERY convincing must make you very happy 🙂 

Steve

I say this because the Iris itself has the progenitor star entirely under control - we see it as a round star not dissolving into the nebula through saturation. We also see the elusive pinks which are often missing and the dust is at once deep and smooth. This is one of those targets which presents very clear challenges!

Olly

[ollypenrice]

8 hours ago, tooth_dr said:

This explains your willingness to help others, and your large amount of patience 😂

We had a maths teacher called Killer Dawson. Doubtless he earned this name through his patience and willingness to help others... 🤣

Olly

Actually I'm only joking. He was (rightly) called 'Killer' but he was an exceptionally effective teacher...

[wimvb]

2 hours ago, ollypenrice said:

We had a maths teacher called Killer Dawson. Doubtless he earned this name through his patience and willingness to help others... 🤣

Gee, I always thought "Dawson" was a completely harmless, ordinary, run of the mill kind of name.

(How's that for selective reading?)

Disclaimer: proper emoji implied.

[wimvb]

On 08/05/2020 at 17:41, Rodd said:

I collected luminance but ended up not using it as it gave no enhancement to the image. 

Indeed, your luminance data has flaws. The central star shows rings in its core, even in the unstretched stage. The brighter stars in and near the reflection nebula have dark rings. I would expect this from a deconvolved image, where the settings weren't optimised. But you wrote that no processing has been done to the Luminance. I will try to repair the core, but not the ringing, and include the L if it adds to the image. You have some very nice colour data, that can take a brutal beating, even in the powertool called PixInsight.

central star

ringing artefacts (most notably in lower left quadrant)

Btw, you can test if the artefacts in the L data are a result of pixel rejection during stacking: just integrate the registered L subs without high range/level pixel rejection. This will leave satellite trails and cosmic rays, but it's a good way to evaluate the stacking process. You can also run the subs through subframe selector and remove those with excessive fwhm values.

[Rodd]

3 hours ago, wimvb said:

Indeed, your luminance data has flaws. The central star shows rings in its core, even in the unstretched stage. The brighter stars in and near the reflection nebula have dark rings. I would expect this from a deconvolved image, where the settings weren't optimised. But you wrote that no processing has been done to the Luminanc

Its possible I uploaded the wrong stack---no matter, the lum is weak.  I did use SFS to cull the high FWHM stars--but conditions were not good.  Just use the RGB.  Unfortunately I do not have the raw subs any longer to check.  I'll take a look at the other lum stacks--maybe I saved on incorrectly.

[wimvb]

I created a synthetic luminance from the rgb data, and will check if that contains the same amount of detail.

[wimvb]

This is proving to be a tricky one; so far, all I have is a muddy mess. I tried to keep the colour saturation in the dust down. In the rgb data there's little evidence that the dust surrounding the reflection nebula must be red, even though it is often presented that way. But so far, this path doesn't lead to anything presentable.

[Rodd]

32 minutes ago, wimvb said:

This is proving to be a tricky one; so far, all I have is a muddy mess. I tried to keep the colour saturation in the dust down. In the rgb data there's little evidence that the dust surrounding the reflection nebula must be red, even though it is often presented that way. But so far, this path doesn't lead to anything presentable.

I found just combining the rgb channels resulted in a pretty decent starting point.  Maybe I uploaded the wrong stacks

[Xiga]

Thanks for sharing Rodd. I will also try and have a go at some point, as myself and the Iris have unfinished business. 

I recently collected about 10 hrs of data with my 80ED and a Qhy163c, but i was so disappointed in the resulting stack that i haven't even bothered processing it. I'm not sure if it's my lack of experience in processing dust that is more to blame, or the combination of my gear & skies, so it will be good to try out another data set and see how things go. 

[Rodd]

1 hour ago, Xiga said:

Thanks for sharing Rodd. I will also try and have a go at some point, as myself and the Iris have unfinished business. 

I recently collected about 10 hrs of data with my 80ED and a Qhy163c, but i was so disappointed in the resulting stack that i haven't even bothered processing it. I'm not sure if it's my lack of experience in processing dust that is more to blame, or the combination of my gear & skies, so it will be good to try out another data set and see how things go. 

My pleasure.  I know this, poor skies and dust definitely do not play well together, so I am sure it wasn’t you 

[wimvb]

6 hours ago, Rodd said:

I found just combining the rgb channels resulted in a pretty decent starting point.  Maybe I uploaded the wrong stacks

The data is ok, and results in a colourful image. It's just that to get there I have to push the colours more than I'd like. And lrgb combination results in a muddy look. Dark nebulae are hard. 

[Rodd]

2 minutes ago, wimvb said:

The data is ok, and results in a colourful image. It's just that to get there I have to push the colours more than I'd like. And lrgb combination results in a muddy look. Dark nebulae are hard. 

I worked on this image for a very long time.  They are certainly hard for me.  I did not increase saturation much at all directly-one small curves saturation boost is all. But I used curves to tighten up the structures, and decreasing brightness always raises saturation.