IC 1805 Heart Nebula, HOO RGB

[firebrand18]

IC 1805 HOO RGB.Jpg (502.19 KiB) Viewed 3644 times

Heart Nebula processed with StarTools 1.9.536alpha. Impressive enhancements with 1.9. Looking forward to beta and general release!

Astrobin: https://www.astrobin.com/7jtl2t/

William Optics GT81 APO @ 81mm/382mm FL
SkyWatcher HEQ5Pro
QHY168C OSC
Optolong L-Extreme filter, 240s subs, 8h8m integration
ZWO UV-IR filter, 120s subs, 1h20m integration
Bortle 8

[Mike in Rancho]

Nice, Nick!

Ah, I see the UV-IR data - was thinking I saw RGB stars in there.

How did you composite that? With 8 hours of L-eXtreme, as a bicolor you might have some blue, or teal, OIII to be separately revealing as well. Of course that always ends up a noise balancing act, as that band is usually fainter.

[firebrand18]

Thanks Mike. Stacked L-Extreme / UV-IR data separately in DSS with reference file, processed each stack separately at same BIN/Crop and used Layer to add 'Color of FG' to the HOO image for star color.

Good question on the blue/teal and have been looking for answers so perfect timing. When I hit the Color Module, I get the expected Red (Ha) and Blue (OIII), however, all the blue/teal is mashed on one side in the sky background, barely anything in the Heart or other similar targets I process in HOO.

Looks like light pollution!

I would hope the Blue would be in the Heart itself (obviously depends which target has lots of OIII) but not the case. Only the Eastern/Western Veil plays nice for this, at least for me.

Having bluish cast on parts of space doesn't do it for me, hence I adjust the RGB sliders in Color module to 'wash out' the blue/teal.

If you have suggestions on how to better process bi-color where Ha/OIII on a target comes out nicer, (not in space) would love to hear it!

Cheers,
Nick

[firebrand18]

Re-processed in 1.9541 alpha with exact flow/settings except in Color module, did not touch Ha, OIII sliders to get the default Bi-Color result with my setup and location; simply adjusted Dark/Bright/Saturation sliders to taste.

I did have to crank the Deringing in SVD to 75% as well as set deringing to 1.1 in Shrink to remove the dark rings, which were not visible in 1.9536 alpha.

Thoughts welcome.

Cheers,
Nick

IC 1805 2021-11-03-04 240s 1x1 10 50 -15C 8h8m v10ff.Jpg (496.93 KiB) Viewed 3528 times

[Mike in Rancho]

Cool stuff, Nick.

I like that a little better on the bicolor balance, even though the change is minimal, but the RGB stars actually appear quite improved.

Good point on trying Shrink afterwards, possibly with no iterations?, to augment the deringing from 541. I'll have to see how that might compare to just sticking with 536. All in flux and will be worked out in the long run of course.

Your Ha/OIII balance in Color was still set to something non-zero though? With a full mask ST can sometimes autosense things and try out an initial balance. Maybe also retries upon hitting the bicolor button?

I know what you mean about the blue-gray fog, and nebular fringes, from a bicolor balance that tries to throttle Ha to reveal OIII. Sometimes there's nothing to be done about it, depending on target. Other times you might be able to suppress blue fog with Wipe (if you weren't aggressive enough to rid yourself of LP gradient, which can be stronger in the OIII), the OptiDev, and/or Contrast, by compressing the shadow dynamic range some.

There is some OIII in the Heart, however. I did this one around October - pretty weak at only 2.25 hours I believe - and still feeling my way around SHO. I should re-stack this and try again in 1.9.

Heart 135m SHO ST8 1B.jpg (476.89 KiB) Viewed 3511 times

[firebrand18]

Nice SHO image Mike! Love the soft coloring; assume with mono CAM and individual filters?

Yes, I often use Shrink with 0 iterations and DR to 1.1; works great to get rid of ringing. I`m not a fan of driving stars into tiny dots; they come in all shapes and sizes so like to showcase them, warts and all!

You gave me good food for thought which I remembered doing on the east/west veil. We tend to assume that when using narrow-band filters, when in Wipe, we should click the narrow-band preset, which is 0 aggressiveness; this may work great for the lucky ones in bortle 2-4 but for us in bortle 8/9, not so well. I normally use Basic at 75% but with your hint, pushed to 90-95% and lo and behold, Wipe did a great job on the gradient and the ugly blue fog on the right side was replaced with a uniform dark teal throughout, including modest tinges in the Heart itself; only so much OIII I can get with OSC.

In Color module, I left Ha at 2.24 and the two OIII's to 1.0 (default) and also clicked the bi-color preset just in case (full mask). Just played with Sat levels again.

Superstructure did a great job as well. Here's my revised HOO RGB in default Bi-color along with equivalent H(H+O)O.

Thanks for the great tips.

CS
Nick

IC 1805 2021-11-03-04 240s 1x1 10 50 -15C 8h8m BiColor RGB.Jpg (518.81 KiB) Viewed 3453 times

IC 1805 2021-11-03-04 240s 1x1 10 50 -15C 8h8m H(H+O)O RGB.Jpg (523.28 KiB) Viewed 3453 times

[Mike in Rancho]

Good edits, Nick.

Yeah that was one of my early SHO tests with mono. Though really I suppose I am still in early mono stage, to be honest.

And yes I've noticed that, especially with OIII, the LP gradients can sneak in so you can't go full bore NB preset in Wipe. Not so much the Ha or SII. But I would have the same when I was using my L-eNhance.

Did you experiment at all with throttling back the Ha from the ST-sensed default balance? I think you can take it farther and show off any OIII you may have captured. Hopefully without blue fogging regions you don't want to!

It may help set off a few areas with the color contrast, perhaps around the upside-down V v v region, or the center...Melotte something?

Might especially go well with the H(H+O)O as the darker blues aren't quite as foggy-prone as teal.

Also if the bicolor preset button plus saturation changes doesn't quite get you the hues you are looking for, don't be afraid to pop the style back to scientific to see how that looks.

[firebrand18]

Good points Mike and yes, have dragged sliders all over the place in Color (and other modules) to see how I can change the balance, including Scientific and Artistic modes; even played around in Filter and Entropy with interesting results; default mask though. A matter of give-and-take unless you start fiddling with selective masks which will then start skewing things; try to stay on the 'normal' path.

I can certainly push the OIII significantly in Color but of course the Ha then reduces so depends what you prefer; strong red-shift or stronger blue shift.

Funny how I really like the H(H+O)O even if pushing the levels harder; blue is more pleasing than the nausea-inducing green tint!

Nick