M20 Triffid Nebula HaRGB 15 hrs.

[Bassnut]

Hi Guys

I was plauged by soft detail on this one, I think the clear nights we have had over the last 3 weeks were not to good seeing wise, as some one already mentioned.

M20 Triffid Nebula in HaRGB total 15hrs exposure time.3nm Ha 11hrs
(27 off 20min subs bin1); RGB each 2hr ( 25 off 5min subs bin2)
Taken on a Meade 12" LX200R OTA, G11, ST10XME. at f6.7

http://fredsastro.googlepages.com/home

Sorry, please scroll down 1 pic (from the M8 pic) to see it.

Thanks for looking :)

[Tilt]

The detail... Its stunning!

:thumbsup:

[skeltz]

Rip snorter of a close up triffid there fred, a real beauty as you say the stars are a bit soft but it is still one hell of an image,well worth the effort:eyepop:
cheers

[AlexN]

I think the color is being dulled out by the intensely brilliant Ha data...

Absolutely awesome image.... thats 3 disgustingly brilliant images in as many weeks Fred.. :)

Excellent image mate. One to be proud of.

[marc4darkskies]

Very nice closeup Fred - lots of detail, nice colour. You've got plenty of data there so I reckon you can tease out more depth without much trouble.

Cheers, Marcus

[leon]

Marcus, be still, :lol: how can he do better than that, it is an absolutely stunning image, :eyepop: well done indeed.

Leon :thumbsup:

[Garyh]

Beautiful Fred! all that Ha gives it a real 3D look!
Like that M8 one too!
cheers Gary

[seeker372011]

nicely split the central stars and stunning detail that havent seen befores-this 15 hours business works wonders, another winner

just crosses my mind-why so little of the surrounding reflection nebula in evidence?

[Bassnut]

Gee thanks Guys, glad you liked it.

The soft stars were on purpose, they look bad too sharp, colour in them is a problem I always have. On the meade, RGB stars are huge, its a struggle getting them to the same size as the tiny Ha (lum) stars to avoid halos, hence the colour gets squashed too. The dust lane detail in the middle sharpenning is where it could have been better. Yes, the Ha lum does swamp RGB colour, I havent got round to the adding Ha to RGB trick yet, Im just getting used to multiple layer masks.

All this teasing is made possible by lots of data, but not necessarily a real increase in depth. That can still be limited by sky glow and sub exposure length. Also, its a trade off bettween sharpening good data and stretching thin data (cant stand much processing) and just showing blury noisy fuzz.

And for my pics anyway with my home rig, the surrounding dim reflection nebula (especially the blue in this pic) is really difficult, or near impossible with 3nm Ha, it more suits emmission nebula, and with 20min subs in urban skies, makes it a no go unforch.

The Lum filter would be better, but then I loose detail, and the ability to image during moon-up. To get a megadata project done in a reasonable time, the bulk of it (Ha) can be done during moon shine if need be, If I used LRGB it would all have to be on moonless dark nights, which could takes weeks, or months.

[bluescope]

Great image Fred !

:thumbsup:

[gbeal]

Stunning shot(s) Fred, very awesome, very.

[RB]

Unbelievable !!! :eyepop:

Stunning work Fred !!!

[Hagar]

Lovely Image Fred, Lots and lots of detail and a real 3D effect on the nebula.

Great work.

[Matty P]

Superb image Fred, just beautiful. 15 hours total exposure time = One amazing image. :D

Keep up the great work. :thumbsup:

I enjoy scrolling down on your website and every image, I keep repeating to myself. Wow!.... Wow!.... Wow! A great set of images.

[strongmanmike]

I think you can handle frankness Fred so......

Hmmm? kind of looks good but I dunno...:shrug: Kinda yukky but kinda ok...? Not sure if it is the washed out colour or soft crackly stars? For the time spent I'd want to see something a little better from you though? What's the go with your star processing, seems to be your nemesis..?

Still, a trifid is a trifid and there is some detail there for sure, so thanks for sharing :thumbsup:

Mike

[spearo]

great shot
but what about that M8 on your site !!!!
OMG!!!!!!
frank

[Bassnut]

Thanks again guy.

Mike, yes well, I know what you mean, someone had to say it, I just kept looking at it and crackly is a good word. I tried different Ha from an earlier shot, and lots of things, it just stayed looking on the border of yukky and detailed, its nice that some liked it, but I can understand why others would see it as a bit messy.

[jase]

I don't mind it Fred, but to the keen eye, it is clear that something is a miss. Nebulosity drops off way to quick in to black/background for my liking. This is actually evident in the histogram reading for the red channel. You've managed to black and white clipped the data. I feel you could have processed this image with more care.

[Ric]

Very nice Fred, it looks a beauty.

Cheers

[PCH]

I have no experience in AP whatsoever, but I think it's interesting that I and others who are perhaps not as experienced as Fred (and Jase and Strongmanmike et al) see an instant wow factor in these amazing images. Surely this is as good as it gets I instantly think.

To me they are beyond description and I could look at them for ages and still be mesmerized by their content.

And yet the experts see deeper than this, and can point out areas that could have been tackled better - in their opinion. This is not a criticism folks, I guess I'm just in awe that someone could be sufficiently adept in this field as to be able to even suggest how these images could have been better !

Does that make sense ? Your whole gallery was, to me, beyond fantastic Fred.

Cheers :thumbsup:

[montewilson]

Nice work - this was done in Sydney ?

[iceman]

It is a nice image Fred, but I know you'll be able to do better. I think the terrible seeing we've had over the last few weeks played the major factor in the softness.

[Bassnut]

Thanks Ric

Jase, things started going pear shaped on loading in fits liberator, stuff it, Ill start again from scratch. Its a puzzle sometimes how different the results are in the liberators strectch algorithims with similar looking masters.

Paul, the problem is the raw data is often pretty ordinary to start with, this is not a top shelf rig, so it needs pushing, which the likes of Jase and Mike can immediately see. I lke the challenge, but it needs a hell of a lot of time in PS to go past the wow factor ,and please the eagle eyed in these hallowed pages.

Monte, yes, in Sydney on the Meade/G11.

Yes Mike, Im supprised sometimes at how clear the sky looks and yet subs look very soft.

[gregbradley]

Another great shot Fred.

I like it. It seems to me to be a matter of choice with this object. In Ha the blue nebula all but disappears (its reflection nebula not emission nebula). Ha will dominate the colour and fade out the reds unless layered in with the red channel and maybe a bit in luminance layer (Ha as luminosity layer). Rob Gendler posted a suggestion about how to combine Ha and LRGB recently. I can email that if you are interested (I haven't used it myself).

You certainly have gotten more detail of the various folds of the nebula more than is normal by a long ways.

If you don't like the stars perhaps try a short LRGB for the stars only and erase the Ha stars and layer in the short exposure. That way you get less tracking error, better colour and less stress!

Your 12 inch LX200 ACH and ST10 are a great combo.

Greg.

[Bassnut]

Thanks Greg. Yes, im aware of Ha/red blending, but haveing tried it recently on this, 3nm Ha subs are very different to regular red subs, they dont mix well, light pollution, and the emission/reflection neb mix might be a factor there on M20.

You have a good point there though, Im thinking of taking lum and adding it to the red, and using it to extend the reflection nebula, whilst leaving the core largely Ha to retain the detail.

Although 3m Ha gives an amazing result, it is difficult to blend with RGB, especially the stars which are tiny compared to RGB.

A short exposure LRGB just for the stars is an excellent idea, haddent thought of that. Come to think of it Greg, its all falling into place now, top input, thanks for that.