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Photographic representation of visual experience

Started by jpcannavo, 10/26/2005 11:43PM
Posted 10/26/2005 11:43PM Opening Post
I was recently trying to describe to a friend how fuzzies look under large aperture and the darkest skies. In trying to do so it occured to me that it would be interesting if there were any photographic images that approximated the visual experience with a large scope under ideal conditions. I later happened on this image of m31.
http://amateurastronomy.org/Picts/pc5.gif
Now apart from image scale (obviously impossible given the limitations imposed by exit pupil) and higher contrast, I was struck by the fact that the this photo seems to only slightly exceeds the detail I have glimpsed under the best conditions with larger scopes under truly dark skies. Thoughts, reactions? Also, is anyone aware of any other photos that provide a similar reference. Also, it would be interesting to process images that attempt to duplicate the visual expereience.
Joe

16" F5 "Front Collimating" mirror cell
Posted 10/26/2005 11:56PM | Edited 10/26/2005 11:57PM #1
I actually see M31 as well as the picture, but with a well defined central point like a star with a larger diffuse area surrounding it. But much like that in the picture. However, you are gathering light for many seconds and adding it up with a photo, which the eye and brain just can not do, so the spiral nature is not as evident.

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager
Posted 10/27/2005 04:48AM #2
You've touched one of my pet peeves, and so I will ventilate it: The magnificent ccd and photographic representations of deep-sky objects that amateurs are now producing are only distantly related to what we see through our telescopes. Sure, they are beautiful works of art. But they ARE artificial. M31 is indeed a blue and gold spiral galaxy with dust lanes, but when we look at it with our eyes, even with the additional light-gathering power of our telescopes, we see a greyish-white fuzzy glow, intense at the core and diminishing toward its extremities. Similarly, we do not see an emission nebula as a billowy crimson and scarlet cloud, but as a luminous ghostly wisp. These images have little more to do with what DSOs look like to the human eye than would a depiction of the mosaics that might be visible through the eyes of a fly.
Of course long-exposure photography has been invaluable in teaching astronomers about the nature of these objects. But I too would prefer photographic images that reproduce the mysterious beauties of what we can see through our telescopes. For starters, when our imaging colleagues publish their highly processed multi-colored ccd images of nebulae, I care to look only at the black & white versions that I believe they refer to as H-Alpha views.

NexStar 8i SCT, Orion 80ED APO refractor, Orion 120 mm EQ refractor, 3.5-inch Questar
Posted 10/28/2005 01:18AM #3
The Cambridge Deep-Sky Album, by Jack Newton and Phillip Teece. You will need averted vision. Just beautiful. It was published in 1983, but you might find a copy used from Amazon or Alibris.
Posted 10/28/2005 09:39AM #4
One thing that is never reproduced in its real visual splendor on the colour photos are globular clusters. I never see that shimmering star dust on CCD images. There might be more stars on a photo, but the eyepiece view is always better, even in a modest aperture.

Open clusters, yes; galaxies, yes; diffuse nebulae - [ almost ] always overblown... Globulars - never.

Dmitri