Astrophotography Processing Challenge April 2024

[TerryMcK]

When I get sometime over this weekend I’ll download and have a play

[KingClinton]

Last month I managed to download a single image and it went into my old copy of startools and PS. I kinda got something to show up but nowhere near your guys efforts!

Now this month is a head scratcher if you are a newbie to this. I downloaded the tif file and it unzipped to 6 images?
What am I supposed to do with them now? I have hit a brick wall.
Any suggestions?

[TerryMcK]

Here is mine.
Processed entirely in PixInsight

• All data run through gradient correction
  BlurXTerminator
  NoiseXTerminator
  HistogramTransformation on all 6 data

• RGB Data combined
  Extracted stars
  Run imagesolver
  SpecPhotoColCal with Chroma RGB filters chosen in calibration for correcting colours of stars as per GAIA3

• S2 Extract stars
  Ha Extract stars
  O3 Extract stars

• LRGB Combined as Ha SHO
  Bill Blanshan and Mike Cranfield NarrowBand Normalization run as SHO for ColorCalibration process
  Convert to RGB Working Space
  Run Curves with some saturation, RGB/K low and mids. Boost high slightly
  Local histogram transform 25 kernel radius
  Local histogram transform 75 kernel radius
  Run ImproveBrilliance script from Juergen Terpe Toolbox
  Set colorprofile to sRGB IEC61966-2.1

Add the RGB stars to the HaSHO image with this PixelMath formula combine($T,RGB_stars,op_screen())

• Run Astro_Swell star_de-emphasizer script
  Add labels
  Export as PNG

[Graeme1858]

Here is mine.

That's excellent Terry! Really well controlled dynamic range and really good colours.

Could you explain your PixelMath formula and have you got a link for the Juergen Terpe Toolbox please?

Kind of makes me want to have another go!

Graeme

[Graeme1858]

Last month I managed to download a single image and it went into my old copy of startools and PS. I kinda got something to show up but nowhere near your guys efforts!

Now this month is a head scratcher if you are a newbie to this. I downloaded the tif file and it unzipped to 6 images?
What am I supposed to do with them now? I have hit a brick wall.
Any suggestions?

The six files are narrow band filtered images of Red, Green, Blue, Sulfur ii, Oxygen iii and Hydrogen α. The captured frames have already been stacked but are unstretched, or linear. I don't know much about Startools. Perhaps a Startools user can advise here. PS6 combines by opening each file (RGB) each on a different layer. Or at least that's how I used to do it in Gimp! Here's a good explanation:





The RGB or the SHO files can be used as a three filter set to produce an image if you don't have a lot of experience (like me!) or you can use the SHO files to produce a starless image and the RGB files for the stars as Terry has done above.

I hope the video helps and I look forward to seeing your work.

Have fun!

Graeme

[TerryMcK]

Here is mine.

That's excellent Terry! Really well controlled dynamic range and really good colours.

Could you explain your PixelMath formula and have you got a link for the Juergen Terpe Toolbox please?

Kind of makes me want to have another go!

Graeme

Thanks Graeme. I used to just use a formula containing %T+stars under the RGB/K tab with create new image in the destination. To use it make sure you change the name of the image containing just stars to .... stars. Then drag the triangle onto the starless image. It will create a new image.

Now I use the formula below that I got from a post on the PixInsight Forum from Russell Croman https://pixinsight.com/forum/index.php? ... ges.18602/
In it he mentions this is the same as recombining the unscreened stars image and starless image in Photoshop using "screen" blending option. The PI people introduced the op_screen parameter in PixelMath and the formula becomes combine(starless, stars, op_screen())

So the formula is this:

again drag and drop onto the starless image and it will create a new one containing the stars and the starless. It gives slightly different results to my original and is more pleasing to the eye.

Juergens repo is at https://www.ideviceapps.de/PixInsight/Utilities/
There are lots of excellent utilities in it and it appears in PixInsight under Script>Toolbox

One thing I forgot to mention in my processing workflow was I noticed that there is a very bright region in the Fish Head that looks blown out. It isn't and detail can be teased out of it by using the HDRMT process set as this.

I normally use the HDRMT process to run over galaxy cores but felt this image needed it too. In the case of the Fish Head I run it just before the "Bill Blanshan and Mike Cranfield NarrowBand Normalization run as SHO for ColorCalibration" process.

The picture looks great as a full size image but it is much too big to upload as the png is about 170MB in size. I had to really cut down the saved file size to upload to the forum but it is always the case with our forums to manage storage space. Of course the smaller size looses a lot of detail but is more than good enough for showing in a web browsers.

[Graeme1858]

Thanks for the extra info Terry. I'm going to go and have a play with the Juergen Script.

The Forum has a 5Mb limit so clicking on an image displays it in more detail. But the best way for high quality images is to right click and open in a new tab, then hit F11.

Graeme

[KingClinton]

Last month I managed to download a single image and it went into my old copy of startools and PS. I kinda got something to show up but nowhere near your guys efforts!

Now this month is a head scratcher if you are a newbie to this. I downloaded the tif file and it unzipped to 6 images?
What am I supposed to do with them now? I have hit a brick wall.
Any suggestions?

The six files are narrow band filtered images of Red, Green, Blue, Sulfur ii, Oxygen iii and Hydrogen α. The captured frames have already been stacked but are unstretched, or linear. I don't know much about Startools. Perhaps a Startools user can advise here. PS6 combines by opening each file (RGB) each on a different layer. Or at least that's how I used to do it in Gimp! Here's a good explanation:





The RGB or the SHO files can be used as a three filter set to produce an image if you don't have a lot of experience (like me!) or you can use the SHO files to produce a starless image and the RGB files for the stars as Terry has done above.

I hope the video helps and I look forward to seeing your work.

Have fun!

Graeme

Thanks Graeme.
I appreciate your feedback. Sounds and looks rather complicated for a visual brain like mine.
Think I might sit this one out. I will stick to trying the single images when we get them.

[Graeme1858]

Would anyone like to contribute some OSC data for a future AP Processing Challenge?

Graeme

[carastro]

KingClinton wrote: ↑Sun Apr 07, 2024 5:03 pm
Last month I managed to download a single image and it went into my old copy of startools and PS. I kinda got something to show up but nowhere near your guys efforts!

Now this month is a head scratcher if you are a newbie to this. I downloaded the tif file and it unzipped to 6 images?
What am I supposed to do with them now? I have hit a brick wall.
Any suggestions?

The six files are narrow band filtered images of Red, Green, Blue, Sulfur ii, Oxygen iii and Hydrogen α. The captured frames have already been stacked but are unstretched, or linear. I don't know much about Startools. Perhaps a Startools user can advise here. PS6 combines by opening each file (RGB) each on a different layer. Or at least that's how I used to do it in Gimp! Here's a good explanation:

I am a photoshop user, but can't say I have ever done this combination myself. I am just about to attempt a process. I would imagine I will try different combinations.

Firstly there is no Luminance. So I would suggest the following.

SHO and simply use the RGB for the stars added in afterwards.

I see some-one else has beaten me to it.

[carastro]

Crikey
Whacking Great files. Took ages to download and ages to do SX on them. In fact still doing it.......... be back some time this month with the result Lol.

[carastro]

Had to reduce this to about a quarter of the original size otherwise could not upload it to Astrobin in order to post here.
Processed entirely in Photoshop.

I have processed this in just SHO (Hubble Palette) as the stars are so small I doubt RGB stars will add anything, but would have taken a lot more time to process.

Mostly levels and curves, I used StarExterminator which I have only just acquired as my old PC wasn't capable of running it. Some High Pass filter and selective colour.

Link to larger size on Astrobin (in my staging area)
https://www.astrobin.com/full/9vp5rd/0/

[Graeme1858]

That's a lovely rendition Carole. Good colours and clarity.

Graeme

[starfield]

Had to reduce this to about a quarter of the original size otherwise could not upload it to Astrobin in order to post here.
Processed entirely in Photoshop.

I have processed this in just SHO (Hubble Palette) as the stars are so small I doubt RGB stars will add anything, but would have taken a lot more time to process.

Mostly levels and curves, I used StarExterminator which I have only just acquired as my old PC wasn't capable of running it. Some High Pass filter and selective colour.

Link to larger size on Astrobin (in my staging area)
https://www.astrobin.com/full/9vp5rd/0/


ZOJgH-NZ0--x_2560x0_esdlMP5Y.png

I like the way you processed the core here. Really clean.

[AstroBee]

Another couple of great versions from Terry and Carole. It really is wild how varied the processing can be. Proof there is no one "right" way to do it as they all have something to like in them.
@carastro For some reason, your image is showing up sort of stretched width-wise, like the aspect ratio got tweaked a bit. Is it happening just on my screen or does anybody else notice this?

[carastro]

@carastro For some reason, your image is showing up sort of stretched width-wise, like the aspect ratio got tweaked a bit. Is it happening just on my screen or does anybody else notice this?

Yes it is stretched on my screen too but if you click on my Astrobin link it will show it properly. I wonder why that has happened, I simply linked to Astrobin using the insert image icon?

Carole

[TerryMcK]

I've decided to enter another one if that is ok? This time processed with the ForaxxPalletteUtility script in PixInsight. Exactly the same process as before but using FPU to combine the mono SHO images into RGB colour.
A little additional curves and local histogram enhance before adding the RGB stars.

[Graeme1858]

I've decided to enter another one if that is ok?

Of course it's ok Terry! You can post as many goes as you like. Glad you're enjoying it.

I like this one. It's darker and moodier than your last post. I like how you have brought out the reds.

Is FPU already in PI or is that a download?

Graeme

[TerryMcK]

Add https://foraxxpaletteutility.com/FPU/ to the PixInsight repository Graeme.
It is very easy to use and some data works better than others.

[Graeme1858]

Thanks for that Terry. I'll have a play later. Got to go to the barbers now!

Graeme