Starless NGC3372

Bassnut (Fred) · #1 24-01-2009, 03:38 PM

Hi Guys

I thought Id give the starless thang another crack

.

Starless NGC3372 Keyhole Nebula
Ha RGB : Ha 12hrs, 3 nm 10min subs bin1: RGB 45mins each, 5 min subs bin2
Taken on a Meade 12" LX200R OTA, G11, ST10XME, at f6.7

Not worrying about stars allowed far more pushing to bring out surrounding detail I havent been able to extract before. Although the keyhole itself aint that flash, the 3nm Ha nicely did the trick generally.

Enjoy

Cheers

AlexN · #2 24-01-2009, 03:55 PM

Awesome narrow field Fred! such intricate detail showing throughout the image..

well done!

leon · #3 24-01-2009, 03:56 PM

Actually Fred that dosen't lot half bad with out the stars, it seems like a fine image to me, nice work.

Leon

lesbehrens (Les) · #4 24-01-2009, 04:01 PM

great

mick pinner · #5 24-01-2009, 04:09 PM

may l ask how you achieve this. no stars l mean.

renormalised (Carl) · #6 24-01-2009, 05:04 PM

Nice image, Fred

Now that you've go the max out of the neb', I wonder what it would look like with the stars put back in, after sharpening them up to the max??

atalas · #7 24-01-2009, 05:11 PM

Amazing detail Fred ! another APOD?maybe.

Bassnut (Fred) · #8 24-01-2009, 05:13 PM

Thanks Alex, Leon, Les and Mick

Dropping the stars was a long story that became a short one.

I took some 5hrs with a continuum filter, its a few Nm off the Ha band so you only get stars (no neb).

I tried to use it to subtract stars, but it doesnt work very well, I cant find anywhere on the net how to use it. As its 3nm, you have to push it like hell, and it still doesnt show as many stars as a colour filter. I gave up.

So, I colour select the stars on a colour sub (nice and big and lots of them), deselect the neb caught in the selection, lasso odd remaining stars painfully time consuming, modify>expand by 6, feather by 4 (then save the selection) and then hammer the selected stars to oblivion with the minimise filter (sometimes in 2 stages, modify>contact by 3 and minimise again).

Heal out giant stars and the artifacts they left.

Sharpening and hi pass masks then become a doddle to use, because theres no star artifacts to worry about. I pulled out more surrounding detail than some who really know what they are doing

.

I thought to myself, this is cheating, but I dont pretend to be accurate, and then, well, most of the stars in any image show forground stars that are not in the subject, so perhaps this is a more accurrate view if you were standing in front of it

.

Bassnut (Fred) · #9 24-01-2009, 05:19 PM

Quote:

Originally Posted by renormalised

Nice image, Fred

Now that you've go the max out of the neb', I wonder what it would look like with the stars put back in, after sharpening them up to the max??

Umm, hadnt thought of that, seems obvious, ill give it a go later

.

Louie, nup, I dont think its up to scratch or different enough. The detail in the keyhole is a bit ordinary. The Meades resolution cant quite go the last mile, some examples ive seen elsewhere are just jaw dropping.

AlexN · #10 24-01-2009, 05:38 PM

All that means is that you need to do it again with the 10" RC + ST8XME Fred...

resolution should be better then!

I must ask, the stars through a 3nm Ha filter must be TINY! did you do the star removal purely for the stars in the RGB images? or do you prefer the look minus the foreground stars?

I might add that I aspire to getting images like yours from my SCT... (I aspire to have clear skies first!

)

strongmanmike (Michael) · #11 24-01-2009, 07:22 PM

Oh dear................over half a a day of exposure ..for that?

In-ter-es-ting I guess..?

Maybe another APOD?

Mike
luv ya Fred

Peter Ward · #12 24-01-2009, 07:45 PM

Interesting. I rather like the "painting look" to the data

Cheers
Peter

Bassnut (Fred) · #13 24-01-2009, 08:16 PM

Alex

The RC has an ST10 now, and same cam angle, mmm could combine subs...

Yes, the Ha stars were tiny, and easy to get rid of, the RGB was harder.

I just did starless for fun, something different, not that I prefer iether way, Ill drop them in again and see how it looks.

Mike, Peter. Not sure if you lot are having a lend or what. No, its not APOD material, and no, its not "painted" at all. Selective masked sharpening and curves thats all (apart from the min filter on the stars).

Peter Ward · #14 24-01-2009, 08:34 PM

Quote:

Originally Posted by Bassnut

Peter. Not sure if you lot are having a lend or what.

Nah...I was not being funny. I really do like the "look" of the processed data. (..hey Fred...thought you'd know by now I'm not PC...even though it gets me into some interesting debates at times

)

AlexN · #15 24-01-2009, 09:35 PM

Fred - I'd get plenty of Ha data from the RC+ST10 to use as a lum and keep the current colour data.... Although after undertaking 12hrs of Ha data already, it might be a real pain doing it all again... Could make all the difference though?

strongmanmike (Michael) · #16 24-01-2009, 09:35 PM

Well I "was" being funny

To me the thought of spending over half a day on such a bright object would demand..?...well?...something more natural and less processed as the first offering. This might rank as a quirky repro but as the main result...? Hmm?

Quite interesting none the less Fred and don't take me too seriously, you know I love playin witch ya

No rules in imaging really

Mike

multiweb (Marc) · #17 26-01-2009, 12:03 PM

Very nice Fred. I Love this starless stuff. That's a beautiful picture. Looks like a painting. Lights and shadows are great. Top work.

Bassnut (Fred) · #18 26-01-2009, 07:25 PM

Thanks Marc, appreciate it, something different at least

.

Alex. Yes, logically lum or Ha would be the go on the RC, much better res, but its "expensive" for me cause megadata on G15 stops paying customers!, ahhhh, the quandry

.

Peter n Mike, yeah, I deserve a rib, and well, like it hehe, I love a good stir up

. And, youve been a bit quiet on that front Peter, whats up?, could I start you up perhaps with a mention on what a heap of junk the RCOS TCC is?, ive been through several over the last few months on G15, the focusing part craps out with blinding regularity, no fix in sight from RCOS so I finally have to resort to a Robofocus retrofit (noticed they now offer this as an option on there web site now?, ask em why

)

Mike. 5 hrs a go is the same effort as 1 hr (set and go, collect result next morning), so why not?. Yes it looks like a repro, but I was hoping for a better result with the ST10 and 3nm Ha (1st was ST8 and 15nm Ha). Also, my view is so restricted, its about the only thing I can do right now (dim stuff is difficult with 3nm Ha, 20min subs at least).

strongmanmike (Michael) · #19 26-01-2009, 07:36 PM

Quote:

Originally Posted by Bassnut

Mike. 5 hrs a go is the same effort as 1 hr (set and go, collect result next morning), so why not?. Yes it looks like a repro, but I was hoping for a better result with the ST10 and 3nm Ha (1st was ST8 and 15nm Ha). Also, my view is so restricted, its about the only thing I can do right now (dim stuff is difficult with 3nm Ha, 20min subs at least).

Fair'nuf

"view is so restricted" huh? Ooooh, what am I hearing? going to "widen" your horizons so to speak are we?

Set and go, reults in the morning huh?...lucky (lazy) bugger!

Mike

Bassnut (Fred) · #20 26-01-2009, 07:50 PM

ooi sport, "wide", as in shorter FL???, wash your mouth out with soap, punk

. Sheesh, me and a poky refractor, not in your lifetime

.