Astrophotography Processing Challenge March 2024

[Graeme1858]

After much interest has been shown we are going to re-start the TSS Astrophotography Processing Challenge. Each month data will be posted and will be available for all to download and process in any way you please.

We thank our good friend David JockinIreland for looking after the AP Challenges for the last three years and for doing a great job.

There will be a change to the way the AP Challenge is presented for 2024. We invite all Members to submit their own data and to present the AP Processing Challenge for that month with a description of the data and how it was captured.

The first 2024 AP Processing Challenge data has been submitted by David and is his excellent Cepheus Dust Cloud. David says:

This is an interesting image to process so will be a fine challenge. It’s a large area within Cepheus and includes several well known targets including the dark shark and the rotting fish, amongst others. It was taken with the Samyang 135mm at f2 and the ASI2600mc and an L-pro filter. When you open the file your immediate reaction is likely to be that I've given you the wrong file. Stick with it! You will then see that there is a horrible gradient. This is intrinsic to the L-pro filter and is easily cleaned with any gradient removal step. I look forward to seeing what everyone can do with it.

So here it is, all are invited, Astrophotographers, Visual Astronomers and AP Curious. What with all the clouds limiting our hobby, we need to take what we can!

TSS AP Processing Challenge March 2024 Data

Click the link, download the data and extract the Zip file to your PC. There is a .jpg file and a .fit file. There are no rules, you can process the files as you see fit in any software you choose. Then post your image in this Thread with a description of the processing method you used for discussion.

Have fun! I look forward to seeing your work. Each month you will be able to vote for your favourite submitted image and the winner will be awarded Forum Profile Flair!

Next Month the TSS AP Processing Challenge will be data submitted by Greg AstroBee.

Graeme

[KingClinton]

Thanks for getting this up and running Graeme!

For a novice at AP processing like myself and many others here on the forums, what would you suggest in terms of software to use for processing? Hopefully something freeware, will GIMP work?
I understand there is superb paid for software out there like Star Tools or Pixinsight. So for us that might want to try without spending and just have fun, what are our alternatives?

[Graeme1858]

For a novice at AP processing like myself and many others here on the forums, what would you suggest in terms of software to use for processing? Hopefully something freeware, will GIMP work?
I understand there is superb paid for software out there like Star Tools or Pixinsight. So for us that might want to try without spending and just have fun, what are our alternatives?

Excellent question Clinton.

There are a number of packages that will do a fine job. Startools is a good example and a good app for people to dip their toe in AP processing. Gimp is a free download, as you mention. Affinity Tools I believe is a freebie, at least a free trial, someone advise please?

There are other free packages too. In addition, a lot of packages give you a time limited free trial, PixInsight for one.

It really doesn't matter what software is used, Paint.net will do the job! The main thing is we learn from each other and have fun.

Graeme

[Jockinireland]

@KingClinton and for those who don't currently do much processing and don't want to spend just for the challenge, there are a couple of options.

Siril is a FREE dedicated astro processing programme. I've never used it but it has a strong and loyal following on some forums. There are plenty tutorials out there and it's available from here

https://siril.org/download/

GIMP is also free but is not dedicated astro. There are plenty people who use it for AP, including some on here. Again, tutorials are out there.

See @cuiv on free software processing with Siril and GIMP.




If you have photoshop, then it also works well, Trevor on Astobackyard gives some good tutorials.

You'd want a 16 bit tiff to use in photoshop so if anyone wants that, ask in here or drop me a PM and I'll make that available.

Just to add, the jpeg in the shared folder is of my finished image so you can see what's there. This is not the easiest image to process so if anyone wants some tips or help with it, again ask in here or drop me a PM.

It's good to see this back up and running.

[Jockinireland]

@KingClinton

Another tip for anyone new and wanting to use photoshop for the AP challenge, you should download two free applications,

GraXpert - this will allow you to easily remove gradients before taking the image into photoshop, it will make your life easier

Starnet++ which will allow you to remove the stars and process the dust on its own before putting the stars back

Both of these are stand alone so will will help with any processing you do in Photoshop, GIMP and other app's but for the cepheus dust image they are especially useful.

David

[Gordon]

You can use StarTools for free, but it won't let you save the image. It's a great way to try it out and play.

[Jockinireland]

You can use StarTools for free, but it won't let you save the image. It's a great way to try it out and play.

For the AP Challenge you could use the free Startools and then just use snip to take a screenshot of your final image to post up here.

[Gordon]

Well,

Here's a quick pass with StarTools.

[Jockinireland]

Thats the L-pro gradient thats giving the green on either side. I cant remember how startools Gradient removal works - its been so long since I used it. But I'm sure it could clean it up more.

[Gordon]

Thats the L-pro gradient thats giving the green on either side. I cant remember how startools Gradient removal works - its been so long since I used it. But I'm sure it could clean it up more.

I'm sure it can be done better. This was a really fast pass. I will try to have another go when time allows.

Thanks for the data David!!!

[Graeme1858]

Here's a quick pass with StarTools.

Even a quick pass shows that there is a lot of dust in the image.

Graeme

[AstroBee]

Here's my go at it and the steps I took using PixInsight.
GraXpert (Gradient removal)
Image Solve (So I could use SPCC)
SPCC, BlurX (Correct Only mode), StarXterminator to remove stars and create a "Stars Only" version.
Starless workflow:
Histogram Stretch on the Starless image followed by Noise Xterminator.
2 passes of Dark Structure Enhance
Selective Color Correction using a green mask as I still had a section in the middle showing up green.
Unsharp Mask and then Color Saturation
Stars workflow:
Histogram stretch to taste. Color Saturation to boost colors.
Combining the Stars and Starless image I used the Screen Stars script and then one pass of the Star Reduction script to slightly reduce the stars.
Exported as JPG.

[Graeme1858]

Nice detail Greg.

Is the red arc to the bottom left part of the nebulosity or a processing artifact?

Graeme

[AstroBee]

Nice detail Greg.

Is the red arc to the bottom left part of the nebulosity or a processing artifact?

Graeme

If you look at David's original processing, that red arc is very, very prominent. It's nebulosity. But for some reason it just didn't pop when I processed it. This makes me believe that GraXpert destroyed a good bit of that part of the nebulosity.

[Jockinireland]

I thought that since some people were asking about non-pixinsight processing I'd give this a go with photoshop and, where possible, free apps. I did a very simple process as follows

Graxpert (free standalone) on the fits file and saved as 16 bit tiff
Opened in PS and curves/levels to to show the stars - very little of dust showing just now
Removed stars (I used starXterminator but could be done with the free Starnet++)
Various curves and levels to balance the background and and brighten/contrast the dust
Produced mask using Select-Colour range to allow adjustment of the Ha in the lower left using curves
smart sharpen
Noise reduction ( I used noisexterminator but it can be done with various plug-ins)
Replaced the stars then used a starmask to allow saturation to be applied

I ended up with this

Its been a few years since I did a full Photoshop process and I'm pretty happy with how this turned out. Its not a million miles away from my Pixinsight version and it was fun working back in photoshop.

[Jockinireland]

Nice detail Greg.

Is the red arc to the bottom left part of the nebulosity or a processing artifact?

Graeme

Nice detail Greg.

Is the red arc to the bottom left part of the nebulosity or a processing artifact?

Graeme

If you look at David's original processing, that red arc is very, very prominent. It's nebulosity. But for some reason it just didn't pop when I processed it. This makes me believe that GraXpert destroyed a good bit of that part of the nebulosity.

Hi guys, yes its definitly real Ha. But it took a lot of selective masking and adjustment to bring it out so much in my PI version. I'm rusty with masks in photoshop so did not do as good a job bringing it out this time. Greg may be right and GX may have lost some of it but I its still there if you dig deep enough.

Heres a link to my PI version at full res.

[Gordon]

Just playing again. A bit more time with StarTools and then a quick pass through with Photoshop.

[Graeme1858]

Just playing again.

That's brought out a lot more detail Gordon.

Nice one.

Graeme

[Graeme1858]

Here's mine.

Workflow:
ABE
DBE
EZDenoise
EZSoftStretch
Starnet2

Then I pulled the starless image into GraXpert to try and remove the gradient. That went well since my pc speakers have packed up and Cuiv's tutorial was difficult to follow without sound! I did the same with the stars only image too.

Then back in PixInsight with the starless image:
Curves, S curve, saturation
I did some more tweaks on the starless version but can't remember the details because after a first attempt at PixelMath I deleted it, lost the stars only image and had to start again to get another one!

Stars only image:
Curves, strong S curve to dim the stars, saturation

Pixel Maths to blend the two.

Another bit of tweaking in Curves.

Excellent data, except for the gradient at both ends of the image. So many stars! I tried a DBE but it just got confused due to the absence of black background. I'm impressed with GraXpert. Although it crashed when I tried to put the unprocessed image in. Does it expect a non linear image?

Good fun. Thanks for the data David.

Graeme

[AstroBee]

.... I'm impressed with GraXpert. Although it crashed when I tried to put the unprocessed image in. Does it expect a non linear image?

No, it works best with a linear image.