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AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 15, 2021 1:06 pm
by Jockinireland
This is my first time doing this and I'm not particularly internet savvy so bear with me if I'm not getting it right!

This time we have some great OSC data from Gordon. This is The owl Nebula, Messier 97 taken with his ASI 533mc in late April 2021. The original post is here viewtopic.php?f=66&t=17883 to give you an idea of what you have.

For anyone who wants to do PCC in Pixinsight, the FL is 1200mm and pixel size 3.76.

The stacked untouched data can be downloaded from

https://drive.google.com/drive/folders/ ... sp=sharing

In there you will find 4 files, Gordons original fits and then an xisf and 2 tiffs which I have saved from PI. The tiffs are available as both 32 bit and 16 bit. I've done the 16 bit because I find it really difficult to turn a 32 bit to a 16 bit in photoshop. I know its supposed to be easy but I just cant do it!!

Download what files you want and process in your software(s) of choice then post in this thread. The purpose of the APP Challenge is to share techniques so we can all learn and grow in our abilities so please describe your process steps and any special tricks you used to get your result. If you have been finding something difficult to do with this data - tell us and hopefully someone will be able to help.

Please consider submitting some data of your own for future challenges. Just send a PM to a Mod or an email to: tssapchallenge@theskysearchers.com

Looking forward to seeing what you can do with this.

Take care

David

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 15, 2021 5:23 pm
by Gordon
Here's my attempt.

I used the 32 bit .FIT file as ST works well with them.

Just the basics settings for StarTools, nothing fancy.

AutoDev
Bin
Crop to center image a remove bright star in upper right corner
Wipe using "Uncalib1" (this did a great job cleaning up the image!)
Contrast
Sharp
Color (used mask to eliminate the stars (this seems to work well).
Final Noise reduction.
A quick sharpen in PS and save as .JPG.
MyChallenge-No-17-Gordon-M9.jpg

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 15, 2021 6:32 pm
by Graeme1858
Jockinireland wrote: Sat May 15, 2021 1:06 pm This is my first time doing this ......

Thanks for taking the reins David, I'm sure you'll do a great job!

We have a week of rain so other people's data is great for me at the moment!

Regards

Graeme

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 15, 2021 6:36 pm
by Graeme1858
Gordon wrote: Sat May 15, 2021 5:23 pm Here's my attempt.

Nice one Gordon. Did you approach it differently from last time?

Regards

Graeme

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 15, 2021 8:53 pm
by Gordon
Graeme1858 wrote: Sat May 15, 2021 6:36 pm
Gordon wrote: Sat May 15, 2021 5:23 pm Here's my attempt.

Nice one Gordon. Did you approach it differently from last time?

Regards

Graeme
I always play just a bit. It’s pretty much the same.

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 15, 2021 11:34 pm
by Jockinireland
Here is my first go at this, thanks @Gordon for the data.

My goals for this process was to try to get the "eyes" of the owl showing up and also get some colour into the stars.

I started with a fairly standard PI process of
Crop
DBE (several iterations to remove gradients)
PCC (colour calibration and background neutralisation)
I am finding that these OSC data sets with new geneartion CMOS dont seem to react well to non linear noise reduction so I did none on this version. I tried a version with noise reduction in linear stage but the background ended up quite nasty
Stretched wit HT
light noise reduction with TGVD
CS for colour saturation (masked to keep background un-touched)
LocalHistogramEqualisation (improve contrast in the nebula)
CurvesTransformation to bring the fainter parts of the nebula and some background galaxies to the fore)

I then took it into Photoshop for a few final tweaks

Increased star colour a bit with carboni's actions
Some tweaking of colour in Camera Raw Filter
Selective Highpass routine to emphsise the "eyes".
Save to jpg.

Giving this;
Challenge No 17-Gordon-M97 Owl_noLinearNR_PI2.jpg
The background is still not as good as I think it should/could be (still a bit lumpy!) so any suggestions for making it better?

I'm going to give it a go 100% in Photoshop to see where I can get to with that.

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 12:16 am
by STEVE333
Here's an attempt using PI. I downloaded the .xisf file (a PI file format).
No_17_Hist_LRGB.jpg

Cropped Version
No_17_Crop.jpg


PROCESSING STEPS:
DynamicCrop
DynamicBackgroundExtraction
ColorCalibration
MultiscaleLinearTransform
HistogramTransformation
TGVDenoise
LRGBCombination
ColorSaturation
StarMask (to add color saturation to stars)
LocalHistogramEqualization
TGVDenoise

Thanks David for taking on the job of running this subforum.

Steve

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 12:40 am
by Jockinireland
@STEVE333 that's really good. Great contrast in the nebula. Is that a result of the LRGBcombine. At what point did you extract the L and how much did you process that before recombine?

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 4:37 am
by STEVE333
Jockinireland wrote: Sun May 16, 2021 12:40 am @STEVE333 that's really good. Great contrast in the nebula. Is that a result of the LRGBCombine. At what point did you extract the L and how much did you process that before recombine?

Hi David,
The LRGBCombine definitely helps to bring out some of the fainter surrounding nebulosity as well as increasing the contrast in the nebula. How I use the LRGBCombine technique is described in the link below:

viewtopic.php?f=22&t=17342

The application of LocalHistogramEqualization towards the end of the processing also helped increase the contrast in the nebula.

Let me know if this isn't clear.

Steve

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 12:03 pm
by Jockinireland
Thanks @STEVE333

So hers mine with your pop applied. Certainly better contrast in the nebula. But i'm not sure where the lime green at the edges came from :lol:
Gordon_owl_s333pop.jpg
and a crop
Gordon_owl_s333pop_crop.jpg

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 4:07 pm
by STEVE333
That looks nice David, you did a good job. Mine came out greenish also. If you apply the PI SCNR process to the image it will remove all greenish tints and will leave a bluish color. I usually apply SCNR to all my images as a final step. For some reason I didn't with this one.

The image below is my cropped image with SCNR applied and then a little more color saturation boost. You can see that all the green tint is gone.
No_17_Crop_SCNR.jpg
Cheers,

Steve

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 4:47 pm
by Jockinireland
Hi Steve, yes I did try SCNR with it but i actually prefer the turquoise for this nebula. Its the more leaf green round the edges of the neb that I dont like so much.

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 4:58 pm
by Jockinireland
When I started to process this I thought that what appeared to be a "smeared" star below and right of the nebula was an optical or stacking artefact. but when I looked at other images I saw it was there in others too. So i decided to try, for the first time, annotating an image in PI to see if I could find out what it was. And it turns out that its a tiny galaxy designated PGC34279.

But what really made my day was to see all the other galaxies in the field. All the blue PGCXXXXX annotations are galaxies which I had no idea were visible. But all can be seen when you look closely. How cool is that?

I thought I'd post it here just for anyone who is interested. And also because its a part of PI I leaned to use for this challenge. for some reason it would not solve the final image so this is a STF (autostretch) of the stack solved and annotated.
Challenge_No_17_Gordon_M97_Owl_Annotated.jpg

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 16, 2021 5:27 pm
by STEVE333
Jockinireland wrote: Sun May 16, 2021 4:47 pm Hi Steve, yes I did try SCNR with it but i actually prefer the turquoise for this nebula. Its the more leaf green round the edges of the neb that I dont like so much.

David,
There is actually some faint red around the edges of this nebula that can be seen is some longer total exposure images. Although only a small portion of this red it is visible in most images of this target it may affect the color around the edges (causing the greenish tint?).

Just my thoughts.

By the way, cool annotated image.

Steve

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 22, 2021 6:51 am
by Graeme1858
Here's my go. I used the .fits file in Gimp.

Curves and Levels to stretch.
The stretch caused Gimp to put a blue cast over the background so I lowered the blue in Curves.
Then I tried to increase the touch of red on the perimeter but Gimp couldn't find any! The surrounding stars all look like Brett's carbon stars now!
Played with colour balance to try and improve the central definition.
Unsharp mask to sharpen.

Challenge No 17-Gordon-M97 Owl.jpg

I need more coffee! Then I'll give it another go!

Regards

Graeme

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 22, 2021 2:08 pm
by Jockinireland
i am still relatvely new to Pixinsight and went through all of the other options before getting here. i do think PI is great but i sometimes wonder how I would fare if I tried going back and using some of the previous options. So I though it would be interesting to try this challenge again in something other than PI. So this is a complete process using ONLY Photoshop CC. And a fairly basic processing at that.

Starting with the 16b tiff
levels to see whats there
crop (this framing was deliberate to see how it looked off centre)
place some colour sample points in background
one iterations of levels (balance black point) and curves to gentle stretch
GradientXTerminator
HLVG
More levels and curves
Masked off background and increased saturation of nebula and stars
Carbonis space noise reduction
final levels/curves
save as jpg

Giving this;
Challenge No 17-Gordon-M97 Owl_16b_FullPS.jpg
I have to say I'm really quite pleased with it for a PS only effort. I'm particularly happy with the background achieved using GradientXTermiantor. My recent PI efforts with DBE have been giving rather lumpy backgrounds as can be seen in my effort further up this thread. The nebula is not as bright this time but I guess I could improve that with a bit more work

Thoughts?

rgds

David.

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 22, 2021 4:49 pm
by Graeme1858
Good experiment. The definition is similar but the red on the edge has almost gone.

Regards

Graeme

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sat May 22, 2021 5:33 pm
by Jockinireland
Graeme1858 wrote: Sat May 22, 2021 4:49 pm Good experiment. The definition is similar but the red on the edge has almost gone.

Regards

Graeme
Thanks Graeme. Yes thats true. I did spend some time trying to boost it but I think that I was probably a bit heavy handed with my initial levels stretches and lost some of the outer nebula including some of the red fringe.
rgds

David.

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 23, 2021 11:44 am
by Ruud
I used fitswork, then photoshop (PS).

Fitswork revealed some red in the outer zone of the nebula: a spot and arc at top left, and a vague arc to the right which never came out well in PS. I managed to amplify the brightest spot reasonably well.

For this version I used Adjust (Topaz plugin). This brings out plenty (real?) detail and lots of noise. It also make for a festive star field:
17 versie 3.png
Here a version without Adjust which is probably more realistic:
17-versie 4.png
I think I found a galaxy (maybe even three) in the oval below and a reflection nebula in the circle.
17 versie 5.png
Thank you Gordon and Graeme, for the data and the contest. Though not easy, it was a pleasure to try and bring out some of the detail present in the Fits.

Re: AP Processing Challenge 17 M97 The Owl Nebula- Gordon

Posted: Sun May 23, 2021 12:43 pm
by Jockinireland
Ruud wrote: Sun May 23, 2021 11:44 am I used fitswork, then photoshop (PS).

Fitswork revealed some red in the outer zone of the nebula: a spot and arc at top left, and a vague arc to the right which never came out well in PS. I managed to amplify the brightest spot reasonably well.


Thank you Gordon and Graeme, for the data and the contest. Though not easy, it was a pleasure to try and bring out some of the detail present in the Fits.
Hi Ruud, thats really good. I prefer the non Adjust one as I prefer the smooth , less noisy nebula.

Check out post #13 above for the annotation of your Galaxies (and a lot more in the un-cropped frame).

Thanks for you post here.

David.