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(IAAC) Re: (NSAAC) New site, new images




Ralph Pass wrote:
>There is more to CCD imaging that just working to get good quality images. As
>John Gall and I did last Astronomy Day, we captured images of NGC 2903 a mere
>30 minutes after sunset. Not great images you understand, but images that
>were better than most can see through telescopes on the darkest of nights.

Ralph has certainly done some amazing things with his CCD setup - and with the
one up at Merrimack. And of course, CCD is already a huge and growing part of
amateur observing and amateur science.

I felt it worthwhile to emphasize Ralph's caveat in the above quote, though:
stacked and composited CCD images will show an incredible wealth of detail in
deep-sky objects of all kinds. However, these details are often related to but
DIFFERENT FROM the details visible to the careful visual observer... The
overexposure problems which plague "traditional" astrophotography are much
reduced with CCD - but not entirely. And of course, the spectral responses of
eyes and CCD cameras are subtly but significantly different.

Finally, the eye is an incomparably fast integrator! It has the ability to take
advantage of very brief moments of "perfect" (or good) seeing, which the time
exposed CCD cannot. (Of course, CCD coupled with an Adaptive Optics system can
already get mighty close to, and probably surpass, the eye's unique ability.)

And in the final analysis, the hard-won techniques of visual observing
ultimately come in just as handy when viewing a finely detailed CCD image as
they do at the eyepiece... A good "visual" observer will probably be able to see
much more in a very high resolution image than a casual viewer might.

And best of all, visual is a whole lot cheaper! ;>

Clear skies!
Lew "John Henry" Gramer


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