Triffid Nebula 2 versions

[BlackNebula]

Two versions of the Trifid nebula, through a 72ed and 80ed. Pretty chuffed with the results! Although think the wider field shot with the ed72 is a bit less noisy.

But, having said this I shot with the ed72 in a bortle 2/3 sky and with the ed80 from my back yard in Perth, so bortle 5/6:)

Both shot with a 533MC on a Celestron AVX

120 sec subs x 37 on the ed72
120 sec subs x 45 on the ed80

[John W]

Good images Mark - I like the first image the best as it shows more of the surroundings. Cheers, John W.

[Dave882]

Great image with really nice colour! Have you considered stacking the 2 sets together? It may just give a bit more depth.

[Bodon]

Marke, great pics mate! Very nice

[oska]

Nice one Mark, great colour. Very well done.

[BlackNebula]

Cheers guys, appreciate it! Stack them together David? Can you do that with them being shot at different focal lengths on different nights etc.

[Dave882]

Yep 100% you can. I use Astro Pixel Processor (APP) and it does it easily and very effectively. I’ve stacked data from my c14 @ 2670mm fl along with my Hyperstar data @ 740mm. There’s a free trial version if you ever wanted to try it out. I’m sure there would be other options too but not sure you find one easier than APP.

[BlackNebula]

Cheers David, never tried APP, I’ve been using Siril and PS. Will give it a try! What about your calibration frames? Which ones would you use?

[Dave882]

Darks and bias can be the same assuming you use the same camera, flats would have to be taken for each change to the optical train.

[BlackNebula]

Thanks, do I just stack all together then? As in the two sets of lights, one set of darks and bias and then two sets of flats all together?

[Dave882]

hey mate- Once you've got APP downloaded, you can pretty much use all the default settings, and just some changes to the following tabs:

LOAD:
tick multi-session, untick multi-channel
Load lights/darks/flats/bias (it'll prompt you asking you what session to name lights, and then when you click on the sub-tabs for calibration frame select correct calibration frames for each session)
REGISTER:
untick 'same camera/optics'
untick 'flip descriptors x/y'
tick 'use dynamic distortion correction' (untick if you get funny stacked results)
INTEGRATE:
You can select various stacking preferences such as % of lights to use based on quality/starshape etc, but to keep it simple you can just leave it all as default and hit INTEGRATE

Give it a shot and if you get any errors or funny results I can help you out!

[BlackNebula]

Thanks a stack David! I’m going to give it a go and I’ll post what comes out the other end :-). Cheers again

[BlackNebula]

Hey David, giving it a go, but have received the following error, any ideas?

Encountered error in module NormalizeCFAChannel

Java.lang.ArrayIndexOuOfBoundsExcep tion: Index 1 out of bounds for length 1

Error repeats 4 times and then nothing:-)

Thanks

[Dave882]

Ok . In NORMALIZE tab, select mode = advanced. Hopefully that’ll fix it

[BlackNebula]

Hey David, thanks got it to work, had exit, restart with selecting normalise and stacked great! Cheers. Just a bit of cropping and post processing I think now as the image came out at an angle and with a strange “square” artefact…

[BlackNebula]

Right, thanks processed through APP and pretty happy with the result, still a slight square “artefact” in the image but I am impressed!

Thanks again for the help and steer David :thanx:

[Dave882]

Looking good mate I'm glad to see it came together!. Definitely deeper colours and background detail, although perhaps some artefacts from noise-reduction/sharpening as well?
It's hard to see exactly all the detail/artefacts in the IIS 200kb version, but when stacking vastly different data sets, you can have some issue or stacking errors/artefracts. You can try changing the 'integrate'/'weights' options to find the best output but I find that the auto function is generally the smoothest for this kind of thing. Use LNC to compensate for differing illumination, and use MBB to reduce artefacts around the joins. Reality is that if you have different data it will have a noticeable difference to the background noise pattern so you may wish to just crop the final output to the size of the smallest fov.

If you've good distortional errors that's probably something back in the Register or Analyse Stars tabs you can fiddle with.

Look forward to more of your stuff mate!

[BlackNebula]

You are not wrong! Much better colours and background details. But, yes had to deal with some serious artefacts. Definitely need to spend more time with APP to get the hang of it.

I processed a mosaic of the Rosette I took a few months back and had been battling with and putting off. It took forever to process but came out pretty good, really easy to stack the mosaic! I’ll post the image soon.

Thanks again