NGC 7380 and surroundings

[Mike in Rancho]

I forgot that we (CN BDSI crowd) did this nebula back in August 22, so decided to retry it in 1.9b. This time I didn't quite go for the perhaps obnoxious full-natural-SHO appearance with all the greens and magentas.

There are indeed a lot of stars. But, I take what the universe throws at me.

Some of them are perhaps a bit wonky. At this stage I don't believe I had completed many of my scope mods and improved collimation. As such, possibly would be a candidate for BXT to repair. Also, some small galaxies I think would look better if they were stars, and fortunately these new tools automate that transformation. Alas, I don't own BXT.

I believe Freddy had more time and thus more detail capture, especially that nice shadow structure that is fairly rare when trying to look for it on Google. Just out of my FOV though, plus I kept the stretch low. Might try again later.

In Compose I reset the exposure times from as-integrated to better reflect actual SNR in Ha, down to the worst in OIII. Still just guessing. I wonder if it would be useful to have a Courtesy OptiDev button in Compose for evaluating SNR channel balance in creation of the Synth L. Not really applicable to broadband, but perhaps very much useful in narrowband.

Used my typical workflow here, Contrast-HDR-SVD Color-DN, no SS, no star Shrink, no Sharpen. SVD seemed to work well other than micro star ringing against nebulosity. And here I found a new trick that worked more efficiently than manual mask creation. I used Auto Star with feature size of 1 and sensitivity maxed to 30. Then a no-iteration Shrink purely for deringing, with dering of 1.1 and color tame zero. I'll see if that also works for other data in the future.

There were no larger star black eyes here, though I did run into that with a no-bin M33 the other night, but took care of that issue with the undo buffer on the offending star. I had forgotten about that.

Other than perhaps the super faint stuff that I didn't acquire much of anyway, I think the Wizard itself still shows through the busy star field. And all the stars across the main nebulosity itself seem to give it proper life.

But lots of stars make for a large jpg, so this was downsampled and compressed more than I would normally like. Also any OS/browser upscaling degrades the image fairly bad. Looks better if I use my non-upscaling version of Firefox for high dpi. I noticed the same with Freddy's image too.

Wizard reproc ST9 1B.jpg (744.2 KiB) Viewed 4651 times

[fmeireso]

I like your most recent rendition on astrobin, Freddy.

When you are using star removal you are probably doing that in PI, right? Is that on linear data or already stretched? Can you then process in ST with tracking on?

Regards
Stefan

Thanks Stefan,

Yes, star removal has been done in PI on the second revision on Astrobin. But not the default module that PI has but I used a script (bettter module) i downloaded. There a split between the nebulae and the stars is done and a starmask is created to protect the smallest stars. And it worked great. Very often using schrink of Morphological transformation in PI reduce the small stars too much and the picture is well ruined. Of course in ST you can make a starmask too, but i find if difficult to select only the very smallest stars.
And i did the reducing on the stretched image allthough i believe that behind the scenes the script undoes that and afterwards reverses it ( i really should review the video because i am starting to forget things allready)

As for later processing in ST with tracking needed, well you might want to fool the software, and say it is linear, and tracking will be on. Off course you can't do too much then in ST, you don't want to do silly things, but you can eg try to denoise it, should it be necessary. Sometimes this works, other times less so.

[fmeireso]

@Mike in Rancho

i made a new one.
Almost completely done in Startool, i do say almost

bin 50 percent
stretched, wiped
hdr
contrast
NO sharpening
Deconvulation, classic
Full color -SII reduce bias to 0
- Ha bias reduce to 2,98
- OIII bias reduce to 0
- Matrix : SHO 50SII+50Ha,50Ha+50OIII,100OIII
entropy, default, i find out it looked a bit better afterwards
super structure , saturate, gamma .8 strenght 15 percent
denoise
saved
I only use PI here to reduce the stars, so i got a starless and staronly image, i did not like the outcome of those 2 together from PI

So back to ST - layer module, mode lighten, reduced to 50 percent

Gimp , little more stretching, more saturation , blue curve a tadd diminished..

Done

LightenStarsOnlyReduced2Gimp (Large).jpg (677.65 KiB) Viewed 4589 times

Decay has it right, in this case reducing the stars cuts hole in the image, but the scripts adds more color to the stars. Although on this jpg here it does not show. My Tiff from ST shows them better ..

That is something to be aware off for the future

[Mike in Rancho]

Hey Freddy,

At first glance I like this one better. Maybe due to being slightly similar to mine, but less stars.

Clicking and looking at the bigger version though, it seems like I am seeing sponge-like holes again. I couldn't tell if you said this version used star removal again - except using ST Layer?

I'm not quite sure what's going on, and I have little experience with Entropy so can't say what that might cause either. I presume you've tried Shrink and SS-dimsmall or isolate in ST, and they didn't produce what you were looking for?

Still, this one passes the stand-off test.

The real challenge would be to stretch more like your first version, to show more of the nearby shadow nebula and dust, but find an acceptable solution to the stars. Maybe I'll try my version again just to see how good Shrink and SS are. I have no shadow nebula like you do though.

[fmeireso]

Hi Mike

Yes the holes are still there, more in the background but still there. They come from starremoval , i am almost sure, i think from the PI script i used here. I must do further investigation, cause there are several parameters in the script.

Still i find it acceptable, but too much enlarged it looses some of his beauty.

But i wanted to redo this image, to see if i could blue out, and yes that works, it is just a matter of choosing the right, or say a better suited matrix.
Anyhow the picture in astrobin comes from PI and that one looks great. But also there too much enlarged one might notice the effect on the stars. Still most people seemed to like it, it has great starcolor imho.

I am learning PI, yes, but not to swith completely to it. I just want to find out how i can make my images better looking. So actually , i am making hybrids..starting out in Startools and tweak it with PI tools or still even GIMP. Many people use more then one software package. Lately i saw a great demo from a guy processing the rossetta. He started out in PI but the last 20 percent the did in Photoshop...

The weather is bad, very bad, so there is not much else to do anyway

CS
Freddy