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Rosette - Single channel colour image


swag72

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Following on from this thread I'd like to present the following image. I have been reticent to post this as I worry that it will draw into question all of my previous and future images and regardless of what I say is used data wise, people will always think I have not been honest about the data used. I can assure you that I have agonised about posting this for that very reason and people that have seen it develop know me well enough that I don't ever want to try to pass this image off as something that it isn't.

This is an image ..... or should I say artistic impression ..... of the Rosette nebula taken with only ONE filter. The data is taken with the Ha filter and I have developed a way of processing which I have coined 'Monochrome Colour Mapping' thanks to Olly's help on the terminology as this describes accurately what I have done.

Details
Mount: Avalon Linear Fast reverse
Telescope: Tak FSQ85 0.73x
Camera: QSI683 wsg with 3nm Ha filter

39x900s in Ha - This is a total of 9 hours and 45 mins. 

I have also deviated from 30 minute subs as I'm not actually convinced that the benefits outweigh the costs...... but that's another story and experiment.

So...... here is the first Monochrome Colour mapped image that I have put out there..... It is exactly as it says on the tin ..... an image consisting of just Ha data and coloured through processing.

I would love to hear your thoughts on not only the image, but also my thinking behind it and perhaps my reticence to post it etc.

 

rosette SGL.jpg

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Ditto Steve. Clearly it's a beautiful image to look at.

Before I react to it on 'philosophical' grounds I'd love to know what causes parts of the image to be the colours they are. The inner part is blue, the outer orange. This does seem to be similar to what happens in HaOIII renditions where the OIII is stronger in the centre. Or take that collection of wispy filaments heading down from the lower part of the nebula to the middle of the bottom edge of the frame. Most are orange but there is a delicate blue strand.

Is it the brighter signal which has become blue? If so this would be a kind of 'brightness colour mapping' which might be analogous with temperature colour mapping as often used in science, industry and medicine.

Or are the colours literrally arbitrary? Unless you did them with the paint brush they presumably can't be, they must arise from some aspect of the data itself.

I guess this does matter to me at some level. It's a very interesting conundrum you're posing here!

Olly

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I think this is very much data dependent for structure -  I don't think any false signal data has been added. However,  I suspect that the colouring is arbitrary and the brightness levels will simply be a guide to the 'artist' as to where colour transitions may exist. The existence of darker portions in the nebulosity will no doubt act to darken the foreground colour in a manner similar to the application of a Luminance channel?

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I don't see much difference in the way we manipulate images to 'clean' them up and reveal faint detail, thus making it a misrepresentation of what is actually visible, and putting in false colour.

In fact if you are putting the colour based on brightness levels and highlighting the fainter areas with differing colours i'd call it an improvement on the norm.

 

Lovely image regardless of any jaleou this may generate [there's a spanish word i love, chucked in in for you sara]

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I have no problem with this image at all. You are just presenting it in a different way. In the same way that thermal cameras show temperature as colour, I presume you are representing intensity mapped as colours.

I once heard someone say at a Photography exhibition - 'This isn't photography. This is art.'    What?!?! Uhhh!!  Well give me art every time. Even if I don't like the result I still want to see new ways of looking at things.

Please keep on experimenting with this. Personally I would have preferred a blend of reds and blues - but what the heck do I know. You have to do stuff for yourself.

And I wish I lived in a place where you could see stars without clouds. Rats!

 

cheers

gaj

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Cheers guys - Interesting comments from you all :)

Regarding the colour, I did 'put it' in a fairly arbitrary place, but I used a number of internet HST images as a bit of a reference, with a little artistic merit of course!

What I find particularly great about this process, is that if you live in a place with little clear skies .... the UK for example ....... then you only need the data in one channel (in this instance I knew that Ha was the strongest and easiest channel to work with) - I have no reason to believe that an amount of luminance data for example wouldn't be able to produce a similar result, Of course, galaxies will still need 'normal data' but with these emission nebula's .... what a great way to save time and get a colour image out from just Ha.

@ncjunk - Off to look up that Spanish word :D

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1 hour ago, swag72 said:

Cheers guys - Interesting comments from you all :)

Regarding the colour, I did 'put it' in a fairly arbitrary place, but I used a number of internet HST images as a bit of a reference, with a little artistic merit of course!

What I find particularly great about this process, is that if you live in a place with little clear skies .... the UK for example ....... then you only need the data in one channel (in this instance I knew that Ha was the strongest and easiest channel to work with) - I have no reason to believe that an amount of luminance data for example wouldn't be able to produce a similar result, Of course, galaxies will still need 'normal data' but with these emission nebula's .... what a great way to save time and get a colour image out from just Ha.

@ncjunk - Off to look up that Spanish word :D

I strongly suspect that your reasoning will find a following amongst exasperated imagers!

1 hour ago, ncjunk said:

I don't see much difference in the way we manipulate images to 'clean' them up and reveal faint detail, thus making it a misrepresentation of what is actually visible, and putting in false colour.

In fact if you are putting the colour based on brightness levels and highlighting the fainter areas with differing colours i'd call it an improvement on the norm.

 

Lovely image regardless of any jaleou this may generate [there's a spanish word i love, chucked in in for you sara]

I do see a difference. It needen't be in any way a condemnation but I do see a difference. Cleaning involves the removal of clearly idntifiable artefacts which did not come from the target. Revealing faint details involves revealing details that are actually there. Inventing colour transitions means inventing them. They are not there in the target. I can't see any equivalence myself.

But that doesn't mean I don't like this picture. I do like it.

Olly

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I like it too - It's a lovely artistic representation (and very pretty :grin:), and I totally agree that this (new?) processing style could prove quite attractive to those of us that are "opportunity-challenged". 

For me, I doubt I'd use it as a replacement for capturing the other channels later, but it takes me back to my DSLR days when I knew I was going to get "a" colour image at the end of a session (even if I needed more data)... whereas since moving to CCD, I've rarely seemed to be able to get ALL data channels, and my wife's comments have been "Well, it's nice, but when am I going to get to see a colour one...?" .   Assuming I had the skills(?!), this could be a very useful process to learn... (anything to keep SWMBO happy :))

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1 hour ago, ollypenrice said:

I strongly suspect that your reasoning will find a following amongst exasperated imagers!

I do see a difference. It needen't be in any way a condemnation but I do see a difference. Cleaning involves the removal of clearly idntifiable artefacts which did not come from the target. Revealing faint details involves revealing details that are actually there. Inventing colour transitions means inventing them. They are not there in the target. I can't see any equivalence myself.

But that doesn't mean I don't like this picture. I do like it.

Olly

This :) .

I too think theres a difference but when the cards are laid out on the table for all to see, then I don't see a problem. It's a stunning depiction of a beautiful object and I will appreciate it for just that. I can understand your torment Sara regarding potential sceptisism to previous and future work you produce. People who know you will accept this for exactly what it is. 

 

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Cheers Andy and Scott for looking and commenting..... I would certainly be upfront about this processing technique if it were used instead of the more usual bi-channel or full HST palette. I'm surprised that this has been accepted as it has - I was sure that there would be many people who would be aghast at me producing publicly something so ......... unusual :)

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I love the picture, but as I said in the other thread, I'm just uneasy about its place in an 'imaging' forum; it feels like it's in a slightly different category.  Olly's distinction between representing real separation in the data captured  and information that is invented is crucial, imo. 

I appreciate that this is not at all the same thing as invented space art: it's a hybrid of actual image data and considered application of artistic imagination.  Maybe this is not a fair comparison, but you often see inexpensive watercolour prints that have clearly had the outlines traced from a photograph (complete with perspective distortion!) and which then have been coloured-in.  In a way, that's a combination of real data plus the artist's skill and imagination.  But is it a photograph or a painting?

Another slight concern is how new/ inexperienced imagers coming to the forum would see it.  Notwithstanding the care and honesty with which Sara has produced this, might others start assuming that anything goes and adopt a more cavalier approach?

 

Adrian     

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6 hours ago, swag72 said:

I have been reticent to post this as I worry that it will draw into question all of my previous and future images and regardless of what I say is used data wise, people will always think I have not been honest about the data used. I can assure you that I have agonised about posting this for that very reason.........

You worry Sara? Really? Who cares what people think? As long as you state "Here is an image I made up from the data from a single filter for artistic purposes", then that is the end of it, surely.

Don't take yourself too seriously, and take other's opinions, assumptions, and misconceptions as a compliment that they bothered looking in the first place, in the end, does it really matter what pictures we take or make, or who thinks what about them? :)

The picture itself is very pretty and appeals to my "Oooo! Pretty space picture!" side. My inner astronomer, such as he is, prefers the separation in colour and therefore elements that come from using a combination of filters.

Come on then, show us another :)

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20 minutes ago, opticalpath said:

I love the picture, but as I said in the other thread, I'm just uneasy about its place in an 'imaging' forum; it feels like it's in a slightly different category.  Olly's distinction between representing real separation in the data captured  and information that is invented is crucial, imo. 

I appreciate that this is not at all the same thing as invented space art: it's a hybrid of actual image data and considered application of artistic imagination.  Maybe this is not a fair comparison, but you often see inexpensive watercolour prints that have clearly had the outlines traced from a photograph (complete with perspective distortion!) and which then have been coloured-in.  In a way, that's a combination of real data plus the artist's skill and imagination.  But is it a photograph or a painting?

Another slight concern is how new/ inexperienced imagers coming to the forum would see it.  Notwithstanding the care and honesty with which Sara has produced this, might others start assuming that anything goes and adopt a more cavalier approach?   

Thanks for this Adrian - I think that you have probably hit the nail on the head with some of the reasons why I have felt reluctance in posting about this, despite having worked on it for some time now. I too am concerned that it in effect blurs the boundaries between an image that is scientifically correct and one that is a recreation of an image albeit using captured data, but an interpretation nonetheless.... I did wonder if it had a place on the forum at all. I wanted to be very upfront about what it was created with data wise and there is no way that I'd try to pass it off as including a full HST data set, although I would challenge people to see otherwise.
Should this processing not be examined or tested further though because of assumptions people make? I wonder what people thought of the first HST image, which has now become the norm for example :)

@Tim - My biggest concern, regardless of what people would actually think about the image was that people would forever be sceptical about the images I produce. It bothers me, not what people like or dislike, but that anyone may think that I was trying to deceive anyone....... if that makes sense :)

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I think it is a lovely image. It shows lots of fine detail and is very pleasing to the eye. I am not an imager myself and I do understand the concerns of some of the experienced imagers, but Sara has fully explained how the colours were achieved. I realise you too Sara have misgivings on posting this image, but I for one would thank you for the pleasure of viewing this lovely object.

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Struggling to use the quote thingy for Neil C's comments, but can't agree there I'm afraid Neil.

If I ever feel the need to 'invent' bits to make an image more appealing, then the astronomer in me will have died.  Sorry for hijacking your thread Sara :hiding:

 

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Nice picture, but it is, as you advertise, 'a fake' and is therefore basically pointless. You have copied existing 'real' images and created nothing new, simply a rough facsimile of a multi filter data set. What you discussed in the other thread made me think that you would use the 'colouring in' technique to highlight specific areas of an image, for instance colouring the animal shapes in the Bok globules in a luminous green to really make them stand out. So, for me, this is not appealing. Stick to the full programme, capture lots of good multi filter data, process it beautifully and create a stunning 'enhanced reality' image that shows us what you captured.

Shocked of Marlborough :hmh:

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I admire your bravery and honesty in trying something like this but it's not for me i'm afraid Sara.  For me the colour should come from somewhere, ie actual captured data. I couldn't sit comfortably with an image that adds information that's not really there in the first place, colour or otherwise. Of course I value others freedoms to do as they please with their own material as long as its transparent to what's been done, as it is here.

Pete

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Thanks Gav and Pete - I was thinking that it was all going too well :)

Rest assured that I will continue with my processing experiments and whether they are pointless or not I shall post them while being utterly transparent about how they have been captured and with what data.... If people like them or not is fine, but anyone can be assured that I will be upfront at every level :)

I appreciate each and everyone one of your commenting and looking at this thread and the other one :)

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