IC 405 and IC 410 - Flaming Star Nebula and Tadpole Nebula

[endless-sky]

I would like to share my fourth image.

With my "lucky week" of imaging, along with M33, I managed to finish also this project. This is my longest integration to date.

These are IC 405 and IC 410, also known as the Flaming Star Nebula and the Tadpole Nebula, respectively, taken over 7 nights, under my Bortle 5/6 home sky.

Total integration time: 18h 29m 00s.

Here are the acquisition details:

Mount: Sky-Watcher NEQ6 Pro

Telescope: Tecnosky 80/480 APO FPL53 Triplet OWL Series

Camera: D5300 astromodified

Reducer/flattener: Tecnosky 4 elements, 0.8x

Guide-scope: Artesky UltraGuide 60mm f/4

Guide-camera: ZWO ASI 224MC

2020/11/18: Number of subs/Exposure time: 41@240s + 1@300s. Notes: L-Pro filter, no Moon

2020/11/21: Number of subs/Exposure time: 48@300s. Notes: L-Pro filter, Moon 46% illuminated

2020/11/24: Number of subs/Exposure time: 48@300s. Notes: L-Pro filter, Moon 75% illuminated

2020/12/07: Number of subs/Exposure time: 15@300s. Notes: L-Pro filter, no Moon

2020/12/13: Number of subs/Exposure time: 22@300s. Notes: L-Pro filter, no Moon

2021/01/10: Number of subs/Exposure time: 37@300s. Notes: L-Pro filter, no Moon

2021/01/11: Number of subs/Exposure time: 18@300s. Notes: L-Pro filter, no Moon

Total exposure time: 66540s = 18h 29m 00s.

Pre and post-processing: PixInsight 1.8.8-7.

This image was particularly hard to process, since there are many bright stars and stretching the nebulosity while taming the stars was quite difficult. I am sure I didn't manage it as well as I would have liked.

Here's a link to the full resolution image: Flaming Star Nebula (IC 405) and Tadpole Nebula (IC 410)

Thanks for looking!

C&C welcome!

Edited January 20, 2021 by endless-sky

[geeklee]

Lovely image - really striking colour and detail in the Flaming Star nebula.  Serious integration time too - well done persevering and adding more and more over the past few months 👍

 

Edited January 20, 2021 by geeklee

[endless-sky]

Thank you for the kind comments, Lee! Much appreciated!

[GiorgioF]

Great one! Long integration always pay back.

You should give a try to starnet++. I'm seeing good result using it on linear stage.

[endless-sky]

Thank you very much, Giorgio!

I tried, but then I don't really know how to work the stars back in, with different levels of stretching. I would like to see a detailed tutorial or guide. It's one of the steps that would definitely improve my post-processing, if I knew how to do it.

[geeklee]

47 minutes ago, endless-sky said:

I tried, but then I don't really know how to work the stars back in, with different levels of stretching. I would like to see a detailed tutorial or guide. It's one of the steps that would definitely improve my post-processing, if I knew how to do it.

Here are a couple of examples applied to your image - not saying they are better, just options you can try quickly to see if they work for you and give you a couple of ideas for earlier in your workflow.  There are so many ways to do this, doing it right at the end on a JPG isn't the best one!

Steps:

Duplicate your image.  Take the original image, apply StarNet with defaults in PI.  On your duplicated image reduce the stretch using HistogramTransforrmation - adjust this to taste once you've tested.  Run StarNet on this but with "Create star mask" ticked.  At the end you'll have three images - your original image starless (A1), your duplicated image with a reduced stretch starless (A2) and the star image from this less stretched one (A3).

Option 1:

Open PIxelMath and enter "A1 + A3" without quotes and replacing names of images where applicable.  Tick "Rescale this result" and "Create new image".  Apply.

Option 2:

Take A2 and using some range mask effort, re-stretch the things you care about.  My sloppy run on the resampled JPG below.

Open PIxelMath and enter "A2 + A3" without quotes and replacing names of images where applicable.  Tick "Rescale this result" and "Create new image".  Apply.

You can also just run StarNet on your original image with "Create star mask" and then reduce the stars and add them straight back with the addition "+" above.  Check closely for any artefacts you don't like and adjust.

As I mentioned above, I've seen so many methods/tutorials for performing this and I adjust depending on the target and the type of stars present (or not use StarNet at all).  With a recent tutorial, I took it out of PI and into Affinity Photo to do.

Check out Adam Block's website and Youtube - with Starnet his method is more straight forward to execute and very effective in it's approach (very different to above).

https://youtu.be/3DdSDoJfjM4

I certainly find stars an extremely challenging aspect in my images and often fail to process to my liking.  Hopefully the above gets you started, if not finished!

Edited January 20, 2021 by geeklee

[endless-sky]

Fantastic guide, Lee! Thank you very much! I'll definitely give it a try tomorrow. If you managed to get such a good result on a JPEG, I should be able to get something decent with the original data. Thanks!

[MartinB]

Great work with the DSLR, lots of faint wispy stuff.  I'm a big fan of Starnet but I really like those big bright stars between the Flaming Star and the Tadpoles, they aren't burnt out, have nice colour and add a certain drama.

[endless-sky]

19 hours ago, geeklee said:

Steps:

Duplicate your image.  Take the original image, apply StarNet with defaults in PI.  On your duplicated image reduce the stretch using HistogramTransforrmation - adjust this to taste once you've tested.  Run StarNet on this but with "Create star mask" ticked.  At the end you'll have three images - your original image starless (A1), your duplicated image with a reduced stretch starless (A2) and the star image from this less stretched one (A3).

Option 1:

Open PIxelMath and enter "A1 + A3" without quotes and replacing names of images where applicable.  Tick "Rescale this result" and "Create new image".  Apply.

Lee, I tried this method and while it works great on the stars, reducing the stretch and their size, I don't really like what it does to the "part of the image I care more about". Let me explain.

If I check the "Rescale result", the stars are blended in nicely, but the main nebulosity loses a lot of stretching and gets toned down. It's almost like the nebulosity matches the stretch of the stars, which - with the main goal of rendering it as clear, bright and apparent as possible - defeats the purpose. If I don't rescale the result, the stars are still somewhat smaller, but their core looks completely saturated. Maybe I need to play with coefficients, instead of a direct 1+1 sum (for example, A1 + 0.5*A3, or 2*A1+A3) and try with Rescaling on and off and see what combination comes out the best.

I haven't looked at the video, yet, but I am planning on doing so, soon.

Thanks again for the tips, but it looks like I haven't found the light, yet.

[endless-sky]

4 hours ago, MartinB said:

Great work with the DSLR, lots of faint wispy stuff.  I'm a big fan of Starnet but I really like those big bright stars between the Flaming Star and the Tadpoles, they aren't burnt out, have nice colour and add a certain drama.

Thank you, Martin. Yes, they do look kinda nice, but I would like to tone them down and reduce them just a bit. I am not a fan of a completely starless image, but I do love when people manage to get the "narrowband effect" on their star sizes.

[geeklee]

47 minutes ago, endless-sky said:

Thanks again for the tips, but it looks like I haven't found the light, yet.

Sorry this didn't work out to your liking @endless-sky - there are compromises using something as simple as the above method.  I've seen some tutorials that utilise the "max" function (e.g. "max(starless, stars)") but you can get harder edges on your stars if done as simply as this.  I didn't think the two examples above (esp option 1) had lost a lot of nebulosity - although it was reduced a little due to the rescaling. Perhaps work on the starless one a little more before blending again?

There are ways with more complex methods & expressions to blend the stars back in as well which I'm sure you've seen.

Without rescaling, you will get a very bright image as it'll just add the values of each pixel together so that's definitely expected!

Definitely look at Adam Block's method next.

[endless-sky]

Thank you, Lee! As long as I succeed sometime in the future, it doesn't matter how many times I fail until then. I'll keep trying!

[geeklee]

Here's the other method (outside PI) that was described by Olly a while back. If you have PS, GIMP or Affinity Photo you should be able to try