IC 1396 - The Elephant's Trunk Nebula - Dual imaging test.

[Taman]

Large emission nebula located about 2,400 light years away in the constellation of Cepheus. The nebula gets its name from the dark globule of gas and dust in the shape of the elephant's "trunk".

First light test of my new dual imaging rig. The weather has been so bad over the last year that I decided to get a second FLT91 to make the most of any clear nights I get.

SHO version using the ForaxX palette, taken over 3 nights. Processed using Siril, Starnet++ and Photoshop.

SII 62x 360s, HA 62x 360s, OIII 58x 600s with darks, flats and dark flats. Total exposure time 22 hours 4 mins.

2x FLT91 & ASI294MM Pro with Optolong 2" filters, i-Optron CEM60EC.

Do the "clicky" thing to see the high resolution image.

Clear skies!

Tony.

[windjammer]

Lovely image.  Quite a lot of noise baked into the nebula - Topaz Denoise AI is a great tool for dealing with it if you haven't tried it.  It is a  plugin for PS and there is a free trial vs to try it out.  The tool is pretty much point and shoot.

Simon

[Taman]

Thanks for your comment Simon, I'm still experimenting with settings in AstrodenoisePY. I don't normally post images at this resolution, but made an exception for this one as there's so much detail! That's my excuse! 😀

Tony.

Edited September 8, 2023 by Taman

[Taman]

4 hours ago, windjammer said:

Lovely image.  Quite a lot of noise baked into the nebula - Topaz Denoise AI is a great tool for dealing with it if you haven't tried it.  It is a  plugin for PS and there is a free trial vs to try it out.  The tool is pretty much point and shoot.

Simon

I installed the trial version of Topaz Denoise and was so impressed I've now got the full version! Here's the result, not perfect but much better than it was. Perhaps it could take a tiny bit more sharpening?

Thanks again Simon!

Tony.

 

[windjammer]

Yes, much better.  I tried it for 10 mins and bought it!.

The standard settings for SN,LL and ST are far too severe IMHO.  So my general approach is to do most stretching in 32 bit mode (PI, AP, PS or whatever), convert to 16 bit and feed it into Tpz. Then check out the ST(standard)  mode. If reduce noise is >20 - 30% to kill the noise I try LL (low light).  If LL at 20-30% does not do the trick, I try the SN (severe noise) mode.  The blur the noise reduction adds increases from ST to SN.  So the enhance detail slider makes up for that.

As usual, the trick is to avoid baking in artefacts early on which are impossible to remove later. You can also use Tpz multiple times in the processing as the issues change - usually in a more and more refined fashion as you converge to a final image solution.

Simon

[WolfieGlos]

Wow, what a difference! I always use AstroDeNoisePY but I get mixed results from it, generally getting "plastic" looking results. I always untick the "normalise" image at the top left so it doesn't stretch it - but it still does slightly.

Topaz looks really good. I think I'll get the trial and see what it does.

[Taman]

21 hours ago, windjammer said:

Yes, much better.  I tried it for 10 mins and bought it!.

The standard settings for SN,LL and ST are far too severe IMHO.  So my general approach is to do most stretching in 32 bit mode (PI, AP, PS or whatever), convert to 16 bit and feed it into Tpz. Then check out the ST(standard)  mode. If reduce noise is >20 - 30% to kill the noise I try LL (low light).  If LL at 20-30% does not do the trick, I try the SN (severe noise) mode.  The blur the noise reduction adds increases from ST to SN.  So the enhance detail slider makes up for that.

As usual, the trick is to avoid baking in artefacts early on which are impossible to remove later. You can also use Topaz multiple times in the processing as the issues change - usually in a more and more refined fashion as you converge to a final image solution.

Simon

Thanks for the info, I've got a lot of experimenting to do! One thing I noticed is that if you leave the stars in, they look a bit odd after the denoise process. I normally work with starless images, so not a problem for me, but it may be an issue for others.

Another thing I will do is to add the denoised image as a layer in Photoshop, that way the effect can be controlled by reducing the opacity if necessary.

Tony.

[Taman]

20 hours ago, WolfieGlos said:

Wow, what a difference! I always use AstroDeNoisePY but I get mixed results from it, generally getting "plastic" looking results. I always untick the "normalise" image at the top left so it doesn't stretch it - but it still does slightly.

Topaz looks really good. I think I'll get the trial and see what it does.

Thanks Chris! I've been using AstrodenoisePY for a few months. I use it on very low settings, sometimes on "0" and I found it's good for removing very fine noise and increasing the contrast. With higher settings it does seem to blur the image though, which means sharpening it again and adding back some of the noise! I only tried Topaz for a few minutes before buying it!

Tony.

[tomato]

Great image!👍

I’m relieved to see that I’m not the only imager to use the UK weather as a reason to set up a duel rig rather than propose the opposite argument.

[WolfieGlos]

12 hours ago, Taman said:

Thanks Chris! I've been using AstrodenoisePY for a few months. I use it on very low settings, sometimes on "0" and I found it's good for removing very fine noise and increasing the contrast. With higher settings it does seem to blur the image though, which means sharpening it again and adding back some of the noise! I only tried Topaz for a few minutes before buying it!

Tony.

Yeah, I get a similar result but then as I lower the setting to 0.6 ish I find I get a lot of colour noise pixels which destroys the detail. I’ve never tried it that low before though, so might give that a go, thanks! 

[Taman]

On 09/09/2023 at 22:51, tomato said:

Great image!👍

I’m relieved to see that I’m not the only imager to use the UK weather as a reason to set up a duel rig rather than propose the opposite argument.

I think the argument has already been won with just this image, 22 hours of data in only 3 nights, although it did take a month to get the 3 nights! 😁

Which scopes are you using for your dual setup?

Tony.

[tomato]

9 hours ago, Taman said:

I think the argument has already been won with just this image, 22 hours of data in only 3 nights, although it did take a month to get the 3 nights! 😁

Which scopes are you using for your dual setup?

Tony.

I have a dual Esprit 150 rig with either ASI178 (for small galaxies) or QHY268 cameras. It takes a bit of setting up and managing to prevent flexture between the two scopes but I wouldn’t go back to a single scope, I want to capture as much data as possible when we get a clear night.