Help with IC1396 (Elephant's Trunk Nebula) processing

[richbandit]

Guys,

Touching base to see if anyone out there might be able to point me in the right direction with my attempts to process some NB for IC1396.

FYI, stacked files can be found here:

https://www.dropbox.com/sh/4iugbjap6fms ... BKkza?dl=0

Each file consists of 2 hrs worth of data, so 6 hours total imaging time ... stacked, etc. using APP in the normal manner I've always done and always works well (I think!), using the usual required flats, darks, dark-flats, etc. ASI183mm Pro Cooled camera ...

I've tried as many adjustments, combinations and 'tweaks' in ST I can think of; also tried several recommendations from some similar posts I've found on this forum, but I just can't seem to get the colour palette correct when I go to the Colour Module- if any 'proper' colour at all! I seem to end up with an over-abundance of one colour or another (depending on how I process it) and very little evidence of the 'other' colours you'd normally expect from a NB image. Tried so many different settings in Colour Module as well, but still unsuccessful.

I've been using ST for quite some time now and I can generally manage to obtain an acceptable result (for me!), but on this occasion it just won't play ball and I don't seem to be able to control the colours at all successfully.

I'd be most grateful if anyone could spare their valuable time to have a look at my data and/or offer any suggestions or advice? Perhaps on this occasion my data's just rubbish - looked OK as each sub came off the camera, and the stacked files don't look too bad I think, but you can never tell I suppose.

Many thanks, in anticipation,

Richard

[richbandit]

Guys,

I think I may need to stand corrected!

It would appear I obviously didn't try everything I could have - I just had another go at re-processing the data again, this time being much more careful/selective with things like strengths, gradients, etc. in various modules along the way, as well as paying more attention to the 'Max RGB' in colour module to assist with balancing colours.

And the result - looking MUCH better, with more of what I perceive as 'correct' colours now showing where they should ....

So lesson learnt for me - don't give up until you've tried all possible setting and 'tweaks', not only the ones you're used to using successfully most of the time.

So, could be I've answered my own cry for help!! However, if anyone would still like to chip in with any thoughts on improving my process, please feel free.

Still need to clean things up a bit, but once completed I'll post a link to the final image.

Richard

[richbandit]

Not the best ever done, but here's my final effort at last!:

https://www.dropbox.com/s/iuvyguw2ylnig ... a.tif?dl=0

Thanks to those who may have looked at my cry for help earlier!

Richard

[admin]

Hi Rich,

Just to give you some quick pointers regardless.

You'd obviously use the Compose module to create a SHO composite, then proceed to process the luminance (detail) in mono until you hit the Color module where the chrominance (color) data is combined with the luminance data. Don't forget to use the Wipe module on your way there - it should not be skipped.

Once in the Color module, the SHO preset should get you started. HST (SHO) palette images usually don't show much green, so balancing out the green is usually the way to go (you can indeed use MaxRGB mode for this).
In the latest versions of StarTools 1.7, you can actually also click on an area and it will "nuke" any green. The Matrix option will allow you to quickly try commonly used SHO blends, though the one dialled in by using the SHO preset is by far the most popular/common one.

One common "issue" with SHO images is purple stars. Some people don't like them, some don't mind them.
If you hate purple stars, there is a little trick you can use to get rid of them.

When you have finished your image (e.g. Tracking is switched off), launch the Layer module. Select "Invert foreground" for the Layer Mode. You will notice that the inversion has made anything that was purple now green. Launch the Color module. Set "Cap Green" to 100%. Keep the result. Launch the Layer module again. Select "Invert foreground" for the Layer Mode to flip the image back to what it was, this time without purple stars.

Finally, if you have a wide field like this with many stars, use the Super Structure (or Life module if you're still on 1.6) to push back the busy star fields.

All said and done, you would have something like this;

NewComposite.jpg (387.46 KiB) Viewed 3741 times

(no detail enhancement, just a crop, bin, wipe, autodev, color, tracking off, layer trick, super structure)

Hope this helps!

[richbandit]

Hi Ivo,

Many thanks for your advice, which is super-useful as always, all noted .... I'll have another go using your suggestions as your end result certainly looks much better than mine!

Yes, I'm using v. 1.6 - hadn't noticed that 1.7 is now available, so I'll download that and try again.

Many thanks