In the wise words of Fred - narrow field rules dude!
Hi All,
It’s been a while between posts, slowly working my way back into imaging after a break. So, I’m pleased to present a collaborative effort between Alvin Jeng from Lightbuckets and I of the infamous planetary, NGC7293 – The Helix Nebula in mapped colour
About the target;
The Helix Nebula (NGC 7293) resides in the constellation Aquarius and is dubbed the "Eye of God". It is one of the closest of all planetary nebula at a distance of approximately 450 light years and is about half the size of a full moon. Despite its size, the light is spread over a large area making it a difficult object for visual observation. The nebula displays different ionisation levels of ejected matter from the dying central star. The inner blue hue indicates the presence of excited oxygen atoms, while the vibrant outer structure consists of hydrogen and nitrogen atoms.
About the image;
The image is a SII:Ha:OIII palette mapped as RGB respectively. Alvin performed the data acquisition on Lightbucket’s monster 24” F/8 RC (4876mm FL). Not a huge amount of data for this target, but not really needed as it was acquired 2x2 bin on the sensitive Apogee U42 camera - SII: 90min, Ha: 60min, OIII: 60min (total 3.5hrs) – all 15min subs – overall good quality data. The binned U42 is only 1024x1024 pixels, so the image presented is actually upscaled by ~60% to show some pleasing details. If the Ha data was 1x1, I think the resolution would be remarkable, though I highly doubt seeing would get down to .57 arcsecs! The upscaling perhaps lost some resolution in the process. The SII data gave me the most grief during the processing, despite the quantity of data, it couldn’t be stretched hard. I will disappoint the NB purist by stating that I blended in some Ha data in to the SII to compensate. The blend however was low – 20%. This settled the somewhat noisy SII data when stretch hard. I constructed two data sets, the first was the SII:Ha:OIII image which was weighted to taste using MaximDL colour combine. I noted the weights and used pixel math to drop equalize the backgrounds between combined subs, and then raise them again based on the noted weights. Seems to deliver a reasonable result as opposed to using clipping masks – change is as good as a holiday right... I was expecting a greater transition of green Ha hue between the SII and OIII, but it simply is not as distinct as I would expect. The other data set being the Ha was ran through deconvolution and used as a luminance to bring some depth and resolution to the field. 2x2 bin still delivers 1.14 arcsec/pixel on the 24” RC so good sampling is present. All layers brought into PS where further colour balance tweaks and enhancement layers such as highlights and noise reduction were invoked. Needed to ensure those cometary globs were in full effect. Experimental, I desaturated the star colour as they typically turn a warm pink hue as the narrowband palettes mix. I think this provides a more aesthetic feel for this target. Talking stars, the diffraction spikes disappeared when I added the Ha data. Not sure what happened there. Perhaps I didn’t stretch the data hard enough. Interestingly, they weren’t very pronounced in the raw data to start with. I even thought I’d remove the stars all together, but thought that would look a little ridiculous considering the planetary nebula’s structure and surely such an activity wouldn’t secure an APOD would it… Presented image is actually a crop of the upscaled frame to work in with website metrics. The full field also captures part of the notorious arm though it is faint with SII data.
Anyway, enough rambling, hope you enjoy it. All comments welcome.
PS. Anyone heading to AIC 2008 this year? I’m there! Need to glean more processing info.
Awesome image of the Helix Jase! Colur balance is lovely (very HST'ish) and the globules are very clearly defined.
Not a critisim but it still looks a tad like it could be even sharper to me but that 24" on the RCOS research mount looks to be a purler .
How much did this image cost you all up to gather?
Be nice to see the uncropped version though as this framing looks just a but trunkated, like looking through a half opened window just begging to be openned right up
PS. Anyone heading to AIC 2008 this year? I’m there! Need to glean more processing info.
Nice web site that, very dramatic and the list of presenters is impressive. Love to attend . Hope you have heaps of fun Jase but how long will your image processing posts on IIS be then??
Thanks Mike. Yes, as I explained in the info, the data is upscaled. The full frame is only 1024x1024 pixels (Apogee U42 2x2 bin), hence lacks a little resolution. Though the data was good enough to scale and hold reasonable resolution. A 1x1 would be a real kicker. Indeed the 24" is great bit of gear, but more importantly is the location where its installed can support it - dark skies, excellent seeing, thus you can get some lovely resolution from the instrument. I think you've asked me about costs before relating remote imaging. Its difficult to put a figure on it - this image was a specific collaboration activity between Alvin and I. The Lightbuckets "easy imaging" facility gives some excellent value for money...even if you simply acquire some high resolution luminance to match it to some low res RGB you've previously taken. At 4876mm, the Helix fills the frame of the U42 so not much can be done on the window effect. I've attached a reduced size full frame for reference. Thanks again for your comments.
Hope you have heaps of fun Jase but how long will your image processing posts on IIS be then??
Just joshing
Mike
Ah, I've still got my bag of tricks I keep to myself. I feel certain I'll learn something new! The Friday workshops will be interesting. Hell of a lot of processing info. Presentations start on Saturday. Should be good fun.
Yes the full frame image is better, a slightly larger FOV would be a bit better even.
So what was the actual cost outlay to "you" to gather the data for this image? Is that ok to ask..?
I realise you can do narrow band in full moon conditions so I imagine this would alter the cost but I am just interested in what it costs in the scheme of things.
Agree, a slightly larger FOV would see an improvement aesthetically, under the proviso that image scale remained the same. When processing this image, my goal was to bring out as cometary knots and as such wasn't overly concerned about the FOV. I think it would look awesome at an even longer focal length. If nebulosity filled the entire frame, I'd remove the stars to make it more of a feature. There wasn't a cost associated with this image as it was a collaborative effort. In any case, I would be reluctant to tell you figures anyway, best to give it try for yourself to see the value and whether its something your interested in pursuing. You do however need to get things into perspective... we are talking about a serious deep space imaging rig here - certainly not for wimps! The Apogee U42 camera costs US$38k alone. The commercials are relative and from my perspective quite realistic. You gain access to premium instruments (24" RC, 20" RC and 14.5" RC, large format cameras) and wait...dark skies. Clearly, the equates to imaging nirvana, but its not for everyone. I still enjoy using my own humble rig, but as the saying goes - variety is the spice of life...and that is what remote imaging delivers.
What a superbly detailed image - the 1600x1200 size is stunning! It’s nice to see all the wonderful detail in this object after my abject failure at the Qld Astrofest to record anything more than a dim haze of nebulosity.
I was probably as excited as the (blue inner) oxygen atoms when I first saw the larger image - top stuff Jase!
I think it would look awesome at an even longer focal length. If nebulosity filled the entire frame, I'd remove the stars to make it more of a feature. There wasn't a cost associated with this image as it was a collaborative effort. In any case, I would be reluctant to tell you figures anyway, best to give it try for yourself to see the value and whether its something your interested in pursuing.
You (and the professional gear) certainly revealed the knots in this shot, excellent! I know this has been discussed a bit before but since it is a great example, out of interest, do you think this image would really belong in an "amateur" imaging contest (should you enter it) given that the raw materials were ordered and done remotely at a commercial observatory with equipment similar or in fact better than that available at Siding Spring Observatory? Just a thought.
Good that you didn't have to pay this time but why would you be reluctant to reveal the cost in other cases? Is it a secret that you can't share? Would be enlightening for some of us I think?
Yes I recon an even tighter framing would be cool too and yes even without the stars, you should try with this image even.
Jase you are still an evil evil man seducing us poor imagers into a never ending chase for imaging perfection.
The detail is stunning but I think I need more practice with my humble setup before I launch into imaging nirvana.
Anyway it is not the destination that is important but the journey!
Thanks for all the fish!
Bert
Thanks Bert! This image is certainly far from perfection (if such a thing exists). I don't like comparing side by side images, but when you compare the hubble image, the resolution is pretty darn good for a ground based telescope. I maybe able to extract more from the Ha luminance through iterative deconvolution blends, but I'm not sure if its worth it considering the scale. I fully concur, the journey is important as a strong foundation puts one in good stead to reaching nirvana. Thanks again.
Quote:
Originally Posted by danielsun
Wow Jase!!
Another ripper!!!
Cheers Daniel.
Thanks Dan. Pleased you liked it.
Quote:
Originally Posted by Dennis
What a superbly detailed image - the 1600x1200 size is stunning! It’s nice to see all the wonderful detail in this object after my abject failure at the Qld Astrofest to record anything more than a dim haze of nebulosity.
I was probably as excited as the (blue inner) oxygen atoms when I first saw the larger image - top stuff Jase!
Cheers
Dennis
Thank you kindly Dennis. The upscaled data seems to hold the resolution well. I'm not going to deny its a tough target. Certainly need long exposures to bring out the details. The U42 camera is NABG, but still required 15min subs through narrowband filters. Alvin did a good job on the acquisition. I think I would have only gone 10min subs and suffered with serious noise when stretching. Thanks again for your comments.
Quote:
Originally Posted by strongmanmike
You (and the professional gear) certainly revealed the knots in this shot, excellent! I know this has been discussed a bit before but since it is a great example, out of interest, do you think this image would really belong in an "amateur" imaging contest (should you enter it) given that the raw materials were ordered and done remotely at a commercial observatory with equipment similar or in fact better than that available at Siding Spring Observatory? Just a thought.
Good that you didn't have to pay this time but why would you be reluctant to reveal the cost in other cases? Is it a secret that you can't share? Would be enlightening for some of us I think?
Yes I recon an even tighter framing would be cool too and yes even without the stars, you should try with this image even.
Mike
I'm not going to fall into that debate again Mike. As it stands, clearly the competition rules don't work and I think you know where I stand...either CWAS/DM awards allow it or not. IMHO, it would be very foolish if they are not visionary in their regulations and embrace this form of imaging. That said, I'm fine for it to be placed in another category to keep you (and others) happy. 24" RC better than Siding Spring's 2.3m scope...who are you kidding?
hahaha I have nothing to hide. Its my business how much I spend on remote imaging and I choose not to disclose such information - simple. Why don't you create an account on the LightBuckets site. Joining is free. You'll find all the information you need, pricing, scope configurations, availability, remote weather reports etc. If you want more information, post your questions on the forum there. The guys are friendly and approachable. Speak with Fred to see if he'll get you some time on GRAS if you're keen. The number of remote imaging players is growing... there is choice. You're a member of MRO aren't you? They've got a 12.5" RC a few guys in the US are using...
Last edited by jase; 16-08-2008 at 02:52 PM.
Reason: typos
Iterative convolution blends sounds like a good new brand for makeup. Highlight your beauty points and cover up the blemishes all in real time! Fantastic stuff!
24" RC better than Siding Spring's 2.3m scope...who are you kidding?
...
Siding Spring has a 16" and 24" and 40" and I think the 24" at LB might well be a fair bit more sophisticated than these even..? Where does one draw the line as to what is pro and what isn't? Do you seriously consider that 24" at LB not a proffessinal grade research instrument? Christ the scope & housing must be worth the best part of $1/2 Million! Who are "you" kidding.
I love your Helix it is truly a nice piece of work but it was done on a 100% pro outfit at a pro observatory, it is no different to the images Rob Gendler has been doing from time to time with data from 1m class scopes in Chile etc, they are great to look at but noone seriously considers them "amateur"
Keep posting them they are great but as fas I am concerned they are not amateur images but rather quirky "out there" semi professional productions.
Carefull how you make your bed Mike, you may need to sleep in it too. Because then the same could also be said about the CCD cameras themselves. As most imagers cant afford a $15,000 + CCD camera outfit (CCD Camera, Filterwheel, Filters etc) so again the same pitfalls reveal themselves here again, as many dont have the ability to own and use a "Professional" Camera outfits.
You may be right though and conditions may need to be set in place in the future.
Im on the fence with this one, as i see both sides has a valid argument.
Jase's in my view represents processing and art, and yours Mike is that of quality of data made available, to produce the final processed image.
Yes Mike it is the age old problem. I personally do not care what other people use. I don't enter competitions for this reason.
When the powers that be have a category where every thing was fashioned by the competitor from the basic elements earth, air, fire and water we can all rest safe that there is no advantage. But we will all have lousy images.
The reality is far more difficult. We all depend on others for our equipment.
My personal opinion is that when comparing images there are a few major considerations.
Technical quality.
Artistic Presentation.
Does the image show what the object is without any distortion from a semblance of reality.
This forum is supposed to be for amateurs, isn't it? So the use of data purchased from a 24" robotic $1/2 Million professional observatory to construct an image from is pushing the "amateur" thing too far in my opinion. It can't be compared to anything else on this forum. As I said Jase's image is nothing short of excellent and its quality matches the equipment that was used to make it, Jase was however provided with the collected data without doing a thing, a paid proffessional outfit of operators did it all for him. Sure Jase used excellent processing skills to assemble the provided and high quality data but why then can't I commision the UK Schmidt or ANU 2.3m scope at Siding Spring (should I miraculaously be allowed to) to take some data for me and compose an image out of that, would this still be an amateur image? There is no difference to me.
To me the line is not blury at all, commissioned data is exactly that ie it is NOT amateur data because it was ordered and paid for using proffessional grade research equipment located at a comercially operated observatory, simple.
Again, this Helix is an excellent image showing superior processing skill but it was done using proffessionally supplied data from a froffessioinal telescope, negating what I believe to be truly amateur, simple.
You all must keep in mind as I write these posts I am smiling and not angry or upset even, I am just talking out loud for a bit of fun about relevant issues. The written word can be missunderstood pretty easily
Very nice Jase, a pleasure to view a top quality narrow field Helix. The zoomy bits in the middle came out very well and detailed, a treat. Yes, I found SII (and OIII) hard to stretch on this, as Peter says the surface brightness is very low.
Dont listen to Mike, who gives a stuff how a member collects the data to for an image to show here (its not a competition), the more variety the better, I certainly enjoy something different, especially when its of this quality. To see results of IIS member processing skills off different equipments is half the fun.
Presented image is actually a crop of the upscaled frame to work in with website metrics. The full field also captures part of the notorious arm though it is faint with SII data. 
. Hope you have heaps of fun Jase but how long will your image processing posts on IIS be then?? 
