An amazing M104

[Bassnut]

I just couldnt help myself, this pic was taken by Richard Murray on my scope (GRAS G15) with relatively short exposures, and including processing with wavelets in Registax!!.

Luminance-20 min (5 min subs), Red-10 min (3.3 min subs)bin2x2, Blue-10 min (3.3 min subs)bin2x2

http://www.amarmur.com/rick/m104-1-20-08aLRsGBweb3.jpg

Its just amazing, and shows what can be done with carefull processing .(registax???, who would have thunk of such a thing with DSO ?).

His web site is http://ricksastropics.blogspot.com/

Tell you what, its symulateously emabrrising and inspirational to see this, must try harder myself ;-).

[sheeny]

I like it! Very nice!

Al.

[MrB]

Impressive detail in the lanes when compared to the HST version: http://us.st11.yimg.com/us.st.yimg.com/I/skyimage_1986_1044566

[Bassnut]

Nice comparison Mr B, thanks, and yes theres a bit more noise in Ricks Pic, but think of what he wouldve done with hrs of exposure time. We live in exciting times Astrophotography wise, its an eye opener.

[vindictive666]

damn nice in my book anyhow :):D;):lol::eyepop:

[leon]

Thats great I have never seen it look like that before, looks a bit like a bowl, nice effort.

Leon

[Tamtarn]

As you point out Fred there is a bit of noise but we can't recall seeing so much detail in any other image of 104 ever before.
Agree with you an amazing image :eyepop:

[Phil]

Holy cow that is very nice well done.
Phil

[rogerg]

Stunning! :thumbsup:

[DJDD]

wow...

[strongmanmike]

Hi Fred

Hope ya don't hate me buuuuut I dunno..?

With the utmost respect to Mr Murry this image looks very strange to me, the colour is pretty all over the place, although I believe you didn't have all the filters installed at the time, am I right? There are strong processing artifacts too and lots of what appears to be...just noise? I can't tell what is real detail and what is simply a result of overprocessing..? The inner ring looks like it is a "real" feature but the outer hallow is just a uniform lipstick on glass like smear with hard edges that bleed into speckly noise. Overall the image is severely clipped and looks rather unnatural and unconvincing to me. sorry. :(

It does hint at what your equipment "could" do but I am certain your superb scope setup is capable of a much better result on M104 than this...?

This is a very nice result using a 14" RC: http://www.astrosurf.com/antilhue/m_104_-_sombreroRChires.htm

Sure Daniels M104 has a much brighter (but very natural looking) central halo region that hides the core (inner ring is faintly visible though) but I can't really match up any outer disc or front edge details from Richards image to that visible in Daniels, this leads me to think that the detail in Richards is in fact somewhat processing induced?

Mike
:help:hope you're ok with that assessment :shrug:

[sjastro]

I have to agree with Mike.

The image is overprocessed which is made worse by the low S/N ratio.
It's an image with potential that can be improved with more data.

Many astroimagers go to the other extreme by mega long exposures which give a very high processing latitude.

Steven
http://users.westconnect.com.au/~sjastro/small

[multiweb]

Might be a noob when it comes to astro photo but I know a few things about processing. Got to agree with mike on this one too. I used registax on planets and moon AVI frames in the past and this program can really screw things up and make you see things that are not there (or that you want to see) if you tweak the settings too much in the 5 channels. :screwy:

I inverted some details on your pic to illustrate. The border line between the glow and the dark shows a lot of noise and I think that's what you might have picked up in the center of the picture that makes you think it looks like extra details. The same noise happens around the bright star.

The result looks real good mind you but I'm not sure it is actually there? :shrug:

[Bassnut]

Hi Mike

Im fine with the assessment Mike, youve got some good points there ;).

The green channel is synthetic, so I guess that would skew colour balance.

I must say, I didnt analyse the image much, other than noticing the noise due to small exposure times , I just found it asthetically striking generally and quite like it.

Its not my image, so Ill just say I like it on face value.

[marc4darkskies]

As a relatively inexperienced imager, I make it a point to blink compare my imaging and processing efforts with others before finalising and posting. I discovered early on that artifacts can easily be introduced by stretching, noise reduction and smoothing low S/N data (if you're not careful). It's easy to inadvertantly process out real detail and process in stuff that's not there. A blink comparison between Richard's shot and others clearly reveals both kinds of artifacts I'm afraid.

Cheers, Marcus

[allan gould]

Steven and Mike
Sorry, can't agree with you at all. As a presentation of M104 and revealing features I've not seen before, I think its brilliant. The inner disk which I hadn't even suspected before is clear and obvious. Just as an exercise that may surprise you, take your long exposure shot and run it through registax. Guess what? - the same features are there.
I personally think its a brilliant shot and may push the boundaries but hey we are amateurs and guess what the professionals are now stacking their shots from a whole series to get the sharpest image.
Sound familiar?
Just my opinion, no malice intended
Allan

[dannat]

I really like it, whether it has faults or not - sometimes faults can look great - at this photo shows:thumbsup:

[sjastro]

Hello Allan,

I have experimented with wavelet processing (using AIPWin rather than Registax) and have never been satisfied with the results.

Steven

[multiweb]

Here's the Hubble version for comparison. :bowdown:

[strongmanmike]

Fair enough and it is an image showing the inner ring so that "is" pretty cool regardless of its asthetics :thumbsup:



Yes I agree, seeing inner ring that clearly is pretty cool but as for the other details ...? an image is an image and it doesn't have to be perfect but I just find this image has lost a lot of what it could have had as a result of the hard processing but hey it isn't a crime just making some observations. The lots of short exposures technique is one to develope I recon and has some real poential on brighter deepsky objects.



Yes I guess you are right :)

[EzyStyles]

very nice M104 there! alot of details for sure. I can understand from where Mike and Steven are coming from. Personally, i do infact think it is slightly over-processed but at the sametime, it clearly shows there are alot of data esp with the inner disc the details are stunning. wavelet in registax have been used abit too much which although sharpens the details, but at the sametime, alot of finer detail will be lost similiar method when using unsharp masking too much in photoshop.

Overall, still an impressive image with alot of detailss. :thumbsup:

[Garyh]

I have similar views to Eric to the image. Has been overdone in registax wavelets that has really brought out the noise and artifacts yet a lot of the brighter details are real while the fainter details are a combination of data, noise and processing artifacts..
I would love to see this image processed using a lighter deconvolution without the artifacts and more ideally triple the data collected.
Still it shows what a 14" RC can really do..
I`m jealous ;)
cheers

[Peter Ward]

Image processing can go one of two ways, either you enhance aspects of an image that are already there, or you create information, that has simply has no physical counterpart.

The latter may still have some "artistic" merit but instantly looses all credibility in terms of information about the object.

This begs the question, at what point does passing a mathematical transformation over pixel values go from "enhance" to "alter".

At one end you could simply use Photoshop and airbrush/or remove any feature you like.....akin to the flawless (and false) complexions seen on models in the fashion mags.....at the other you would would highlight every single pore/mole/zit on Jen Hawkins' (still very pretty) face...and hardly the way to sell cosmetics....but from an astronomical imaging point of view far more valid, as that process is simply highlighting something that is real (albeit not as severe) and you are making it easier to see.

Astronomical image processing errors can include dark rings around stars, noise removal (smoothing) that removes data, and our old friend colour balance, ie making something inherently red look blue ;)

Learning how to deal with these issues can be a lot of fun, but for the most part I've found you need good data to start with. As the old saying goes, garbage in, garbage out.

[Bassnut]

Peter

mmm, "enhance" to "alter". Very valid point. You could also argue there are 2 other kinds of images, artistic and accurate. Just about all NB pics fall into the former for instance, given colour rendition is abitrary. I find myself sometimes looking at astropics just looking for something different . 3D ness, wow ness, striking colour, whatever, just to seperate it from the norm. The ring artifacts here may well be induced thru processing, but in all honesty, without a comparison, id rather see sharp "dust ring like" detail than accurate blured blotches. I think this M104 gives a better "feel" of how the galaxy looks like generally than a blured accurate rendition. Now, before I get flamed to hell, of course, obviously, Id rather see a razor sharp super accurate Hubble pic, but ive already seen that. Given this was done with something less than Hubble, with short exposure times and a synthetic green channel, I recon it "looks" great. Most over processing just looks wrong and does the image no favours. In this rare case, I think it actually improves its "viewability", without seeming like deliberately cheating.

[Zuts]

Hi Fred,

What you have done is no more than what Peter Ward suggests us DSLR folks do. Up the red during processing which our cameras cannot capture so we dont get blue spiders. To my eyes the image does not look very overprocessed, even if we spend 100,000 bucks on equipment we cant have a hubble; and i think the processing you have done has produced a very striking image and allowed us to see more (rather than less) of what that galaxy looks like.

When it's all said and done I think that it's a bloody good image.

Paul

[Peter Ward]

I never said the image Fred pointed us to wasn't striking (Fred already knows I gave it a big thumbs up :) ) . But that was not my point.....

I find it laughable for example to suggest, under certain lighting conditions that if a camera renders a models face as green/blue/purple, it be deemed acceptable even though she has pink/fleshy coloured skin.

Image correction is a whole different subject ;)

(Many (daylight) photographers go to some lengths to get the white balance right in their cameras for that very reason....but I digress...)

Getting back to image enhancement, some pretty caustic filters do apply transforms which radically highlight subtle physical processes. There is nothing wrong with that, as this reveals detail that is there, but very hard to see in the original data.

But I'd suggest that is very different to buggering things up to the point where there is stuff in an image, which simply doesn't physically exist.

...but hey, if making the moon look like green cheese makes you happy....go for it......:lol:

[Bassnut]

Paul, Im with you on that, but a quick reminder, this image is by Richard Murray on my scope, I cant claim credit for his masterfull processing ;-).

[Zuts]

Sorry Fred,

I thought it was one of yours.



Hmm,

I dont make it look blue :), my camera does. With no post processing it is blue. It has a cutoff above Ha.



By buggering it up do you mean leaving it blue (the tarantula is more brownish, lots of Hb) or do you mean adding the Ha colour that does not physically exist in the data as captured by my camera.

[Bassnut]

Look, on second thoughts, Im uncomfortable with "adding" to data that isnt there, thats why ppl send **** loads on gear to start with good data, and its the driving force amongst us all to present truthfull images, other wise you could photoshop master pieces from a $50 Tasco. Im somewhat torn asunder on the way this topic has progressed, I dunno, we often process so much that the real-artistic divide gets blury. As long as the intention is understood, then all is valid I guess. I can be impressed by both approaches.

[Peter Ward]

Paul,

Using an instrument that simply does not record the red bits, does not change the colour of the object. It will however change how the instrument records the object.

Hence my comments on alter vs enhance. If you know the instruments shortfall, then you can compensate for it, and get something that better approximates the original.

To make arbitrary changes (eg green moon) or generate synthetic processing artifacts seems pointless to me

To enhance some aspect of information within the (calibrated) image data....as shown by Richard Murray...takes some skill...and I tend to agree with Fred, can give image a "wow" factor that is often hard to find.