Color in space is a topic that has puzzled me too. (We can get philosophical and wonder if one person perceives vision itself the same as another, which is challenging to think about.) Concerning color photos of deep-space objects, I think the reproductions do have some validity. That is, if five astrophotographers using the same filters and exposures compare their work, they would be similar. There is a basis for the color, some objective reality in space. The tints are not the same as we can see with our eyes because our eyes are highly limited instruments, needing a certain intensity of light to see color at all. And there are plenty of electromagnetic wavelengths out eyes can't perceive at all. When CCD cameras gather light over long periods, they are improved versions of our eyes, accumulating and multiplying the photons, so they recognize color in dim objects we could never detect without such help. But the colors really are there in the sense that we can record them. Probably actual wavelengths of colored objects in space could be measured to give particular tints and shades. But I'm also sure there is a big component of art involved in making astrophotos. We need to take into account such things as how much the atmosphere distorts the colors, making the problem awfully complicated. That's just my opinion and maybe others in the group could improve my understanding. -- Thanks, Joe --- On Tue, 12/1/09, Chuck Hards <chuck.hards@gmail.com> wrote: From: Chuck Hards <chuck.hards@gmail.com> Subject: Re: [Utah-astronomy] M51 reprocessed To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Tuesday, December 1, 2009, 11:23 PM Don't beat yourself up, David. Saturated colors in astronomical images are all fake. We try to approach what the various objects might look like if they were actually bright enough to trigger the color receptors in our eyes, but all deep-sky astronomical images are really just art, when it comes right down to it. An article in S&T some years ago (and even a "Sky-Wise" cartoon by Jay Ryan) demonstrated that even if we were much closer to these galaxies than we are, they would look about like the Milky Way looks to the naked eye from a dark site. Impressive, yes, but not tinted blue and red. Even if we were immersed in the Orion Nebula, the brightest parts would appear as a colorless, grey vapor instead of the red we are used to in photographs, or are on the verge of detecting visually in large aperture scopes. The colors are thanks to our insturmentation. The challenge in astro-imaging is to pursue ever smaller star images- crisp, tight focus. Diffraction-limited imagery. The colors are just what pleases the eye. This one does match what we are used to seeing much more closely. Keep up the good work! On Tue, Dec 1, 2009 at 6:52 PM, David Rankin <David@rankinstudio.com> wrote:
I didn't realize how bad the processing on my M51 shot was until I got home. I started over on a real monitor, and here is the new result. I had way over saturated the reds before.
http://www.slas.us/gallery2/main.php?g2_itemId=2718&g2_imageViewsIndex=1
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