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Greg,
My thoughts on a subject that can have no single right answer.
If you have performed a G2V calibration and removed any colour gradients, what you have left ought to be a fair representation of the "real colour" . . . assuming you havent done much in the way of non linear transformations with your colours or blown out any channels and attempted to capture equal amounts of each colour channel in the first place - considering that different channels may have different signal to noise ratios given the weak amount of actual data (photons collected) we rely on.
What you do from there on is your business !
But even with G2V calibration, the spectral sensitivity of your CCD, the filters and your optics as well as the local atmospheric colour extinction etc will all have an influence on the relative colours and brightnesses.
The fact that we frequently enhance Red with Ha, as well as dramatically exaggerate our luminance channel with Ha to draw out interesting contrast detail (and therefore even more of the Red channel) and that our CCDs convert some IR into Red and some UV into Blue means that colour integrity is ultimately destroyed.
But in saying this - what are you trying to do - Was colour the purpose ? or rather the use of colour and contrast to portray a particular target in the best possible way to illustrate whatever features of interest your image is intending to show and highight ?
As already stated, our eyes cannot see most of it in the first place - its just too dark, but our eyes can only detect a relatively narrow part of the whole spectrum in any case - so what is real ?, what is right ? and more importantly what is wrong ?
For Astro Imaging its more a question of the philosphical approach of the imager for that particular target.
Should we eliminate spectrally aesthetic features because we cant see it with our own eyes ?
Should we ignore visually interesting detail just because our camera happens to detect more IR and UV than someone elses ?
Unless you are attempting to repesent your images as having scientifically accurate colour, your image is what you make it.
And generally it wil be judged by you and maybe others in that way.
AP is not like terrestrial photography to the extent that the image processor (you) is required to process and manipulate vast amounts of colour channel information and the ultimate aim is usually to show interesting detail rather than represent any subject or colour faithfully and use the interplay of light and composure in an interesting way.
But just an a terrestrial photography uses shadows and highlights in his image along with much greater opportunities for composure, perspective and depth of field etc and to create an image that provides us with a pleasing view - they too are manipulating the colour balance and brightness levels
We just dont have the opportunity of the latter to play with (ie depth of field, composure, perspective etc)
I prefer colour that looks realistic, not exaggerated or flouro, not oversaturated, I prefer images with stars that look like they are generally correct, but thats just me and that still leaves plenty of room for variation.
I thik the black art of Ap is to produce a pleasing visual image that retains elements of natural colour and beauty, but maybe also teases out the really interesting details and visual effects that make that image personalised and unique.
Rally
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