I should preface a ‘mainstream target alert’ for this image. Yes, the Tarantula Nebula…Hohum. Ironically I found this to be a complex target to process. I have imaged the area before as wide field mosaic so had a sense of what a traditional LRGB palette should portray. Imaging this at a longer focal and putting some narrowband into the mix, I had no idea what challenges awaited. Thankfully the data set was good to work with, especially Ha and OIII data packing some punch. The area is abundant with OIII so clipping masks assisted in getting the right balance or near to the wide field which was used as a general reference.
Cheers Mike. Yeah, its tough to show a common target in a different light. The OIII blend really dominates the scene and mutes the deep Ha reds I'm more familiar with. I had some fun with the data set despite the challenges.
Well, it’s good to see you breathing some new life into these more familiar objects.
I loved the full res view. I hadn’t realised how tangled and interwoven the web seemed until I peered more closely at the innards on my 1920x1200 monitor. The spectrum of stellar colours is quite exhilarating as are the rafts and concentrations of blue stars.
Masterful processing to display both the intensity of the dominant objects yet reveal the subtlety of the more timid entities.
Hi Dennis,
Thanks for taking a look and providing a shrewd response. Thoroughly enjoy reading your posts. I paid particular attention to the stellar profile and colour throughout the processing cycle. To get the stars as tight as possible, I predominately used the narrowband data which was iteratively blended with the RGB to minimise stark and ugly halos appearing. I’m sure there are other approaches, but this seemed to work well for this image. Thanks again!
Excellent portrayal of this magestic maelstrom Master Jennings, I must say!
Such a plethora of trinkets on visual display, I am simply overwhelmed with curiosity...how many stars will all that cosmic material eventually become? The mind boggles...
On a minor note and while not that important in the scheme of things, might I note however that the core region is perhaps wanting of a little more attention just to reveal a modicum of more structure and a slight increase in colour dynamics?
Overall though, a glorious view of this southern commoner
Nice and sharp for such distant nebulosity, Jase. Love the colours too.
Thanks Rick. Very little sharpening was required with the data set, only mild deconvolution. I stayed away from high pass filtering as well as unsharp mask. I did try them, but the gains were minimal.
Quote:
Originally Posted by strongmanmike
Excellent portrayal of this magestic maelstrom Master Jennings, I must say!
Such a plethora of trinkets on visual display, I am simply overwhelmed with curiosity...how many stars will all that cosmic material eventually become? The mind boggles...
On a minor note and while not that important in the scheme of things, might I note however that the core region is perhaps wanting of a little more attention just to reveal a modicum of more structure and a slight increase in colour dynamics?
Overall though, a glorious view of this southern commoner
Sir Michael
Dear Sir Michael,
I most appreciate your time in reviewing the presented image and providing a thoughtful response. It is with absolute gratitude to receive your constructive feedback. The nebulous core surrounding 30 Doradus could possibly do with additional work however one must remember to ‘respect the light’ given it is distinctly bright.
Sincerely,
Master Jennings
Aside from the whooping amounts of colour - not overdone for a photo btw - I think this image most closely resembles some of the views I've had through large scopes of this nebula. Dappled and 3D. I love it.
Dear Sir Michael,
I most appreciate your time in reviewing the presented image and providing a thoughtful response. It is with absolute gratitude to receive your constructive feedback. The nebulous core surrounding 30 Doradus could possibly do with additional work however one must remember to ‘respect the light’ given it is distinctly bright.
Sincerely,
Master Jennings
Sorry, my error, perhaps I failed to make my observations clear. I don't feel the core needs to be dimmed per se, on that score you are absolutely correct . I was simply suggesting an increase in the colour dynamics in the bright areas, if that is even possible? To my demented chromatically challenged eyes the core brightness and colour seems to have a slightly pale lifeless appearance which is reducing the 3 dimensional depth that might otherwise be achieved..?
Please be aware that this observation is quite minor and the image is excellent, I probably have a psychological and thus disproportionate fixation on the core of this famous cosmic landmark, that's all...I may need to consider admitting myself to a sanatorium for an indefinite period...
Aside from the whooping amounts of colour - not overdone for a photo btw - I think this image most closely resembles some of the views I've had through large scopes of this nebula. Dappled and 3D. I love it.
Cheers,
Cam
Thanks Cam. The different colours in the area sure make for a busy scene. I'm pleased that the structure closely resembles some of the views you've had through large scopes. If I could see a scene like this in all its glory, I'd go back to visual work immediately! Much easier than hours on end processing.
Quote:
Originally Posted by strongmanmike
Sorry, my error, perhaps I failed to make my observations clear. I don't feel the core needs to be dimmed per se, on that score you are absolutely correct . I was simply suggesting an increase in the colour dynamics in the bright areas, if that is even possible? To my demented chromatically challenged eyes the core brightness and colour seems to have a slightly pale lifeless appearance which is reducing the 3 dimensional depth that might otherwise be achieved..?
Please be aware that this observation is quite minor and the image is excellent, I probably have a psychological and thus disproportionate fixation on the core of this famous cosmic landmark, that's all...I may need to consider admitting myself to a sanatorium for an indefinite period...
Tally ho
Ahhh colour dynamics hey. Well, there lays a challenge. Preaching to the coverted here but RGB being an additive colour space, you can only colour scales of grey. A bit map of 255 is all white. So, yes I could introduce colour dynamics of the highlights by lowering their intensity to several counts below the 255 threshold to bring back the colour. Truth is however I did absolutely no specific core work on this image. It is simply DDP stretched in CCDStack, then slightly brightened up further to finish it off in Photoshop. I intentionally did this to display the intensity relatively to the main structure which I felt was more important i.e. depict the features in the scene relative to brightness and intensity. The OIII data is nearly a rich as the Ha for this target which is why you don't get the deeper reds, certainly not around 30 Doradus anyway. Object masks etc would have likely driven a different result but not the result I was striving for. Thanks again Mike.
It is a splendiferous image of an oft-too imaged region. Really impressive indeed.
You apologised it was the Tarantula - thank goodness it was not M42 or we would have to whacky-thump you into submission.
(though, I am sure the RCOS would deliver a supreme result on that FAR TOO OFTEN imaged chunk of gas in Orion)
Pleased you liked it Lewis. I do have plans to image M42 (for the first time ever with my own equipment would you believe) this season, time permitting. There are some other targets already loaded in ACP Scheduler that hit the meridian around the same time so it may have to wait another year (system is configured automatically to favour targets near the meridian before dispatching a plan, but I could override this). I would imagine to do it right it is going to take some work. I've been reading up one CCDStack's replace missing values to perfectly blend saturated areas with non saturated data. PI has similar functionality I believe. This will helpful in managing the dynamic range though at a slow F/9 I shouldn't need to worry too much.
Quote:
Originally Posted by IanP
Lovely image, balanced in colours and rich in details.
Cheers Ian. Sure is an impressive area. I can see why it ranks high amongst imagers and visual observers alike. The histogram confirms the balance but its easily perceived with this image. Thanks for checking it out.
Jase, can you send me the link to that CCDStack info. I am a complete CCDStack convert - it is an incredible bit of software, far superior to anything else I have tried.
Oddly though, like with MaxIM, it seemingly dislikes OSC camera images IMMENSELY, showing visible bayer matrix abberations no matter the settings.
Anyway, a corker image. You should be very proud of that result indeed.
Lewis, agree hard to beat CCDStack for the grunt work. Not sure if you've seen Adam Block's supplemental CCDStack v2+ tutorial (here, password provided. Make sure you download it for best viewing) where he explains the calibration management capabilities and automated scripting tasks of the app. I've just started doing this to save time. Matching items in the FITS header is great for flats. My system has an instrument rotator thus need to take flats at different PA's and E/W of the mount for accurate flat correction. Having CCDStack automatically match the flats to the data is real treat. CCDStack only gets better.
Re: replacing missing values in CCDStack. You my friend are in luck. At AIC back in 2009 (or was it 2008, ah can't remember), Adam was handing out free tutorial CD's specifically on the topic. Shoot me an email or PM, and we'll see what can be done.