Best Lunar Photograph I Have Ever Seen

In article , Davoud wrote:
palsing wrote:
$10,000 won't even buy a really good mount these days...

Chris L Peterson wrote:
Fortunately, high resolution lunar imaging doesn't require exceptional
equipment. You could pull this off with a few thousand dollars. The
magic in this shot was in the image processing- what you could consider
post processed adaptive optics.

The 1280x960 15fps camera can't have hurt - has the image processing
managed something clever like merging optimally-sharp portions from
multiple frames? Or is 10" still small enough that the atmospheric
distortion in a lucky frame is uniform across the frame?

I'm not quite sure what the note at the bottom means; I interpret it
as eight pointings from each of which you take a thousand frames.

14.6 metre focal length onto five-micron pixels is I think (5e-6 /
14.6 * 180 / pi * 3600) 0.07 arcsec per pixel, which is substantially
oversampling the diffraction limit of a 10" mirror; about seven pixels
per kilometre on the Moon's surface! I'm not sure if the image on the
Web is at that scale.

Tom

Davoud wrote:


Waste of time though it is,


Then stop it.


let me try to disabuse you of your mistaken
notion about Mac software for astronomy, and across the board. While
there has certainly been less of Mac software than there has been
Windows software, Mac software is uniformly better than Windows
software in terms of ease of use and stability.

Not true. And you can't prove it. Given your adoration for all things
Macintosh you are hardly what I would consider unbiased.

And for the record, my imaging software that runs on XP has never
crashed. And either has the computer for that matter.



[more Mac drivel snipped]

Bill

Davoud:
[Tirelessly Mac advocating]

John Steinberg:
Let the Philistines enjoy their cheap, buggy and ugly toys, David.

Asking them to understand the sublime pleasures of the Mac is like
asking you to enjoy an evening of Governor Palin's elocution.

Indeed. Just between you and me, it's still true--if you don't get it,
you don't get it. That is an observation, not a criticism; there are a
lot of really simple (I'm told) things I don't get. The Simpsons.
Sushi. Omniscience.

As for Palin, she was fun while she lasted. It might be fun if the
neocons maintain their (death) grip on the Party of Nixon and roll her
out four years from now. It might be good for the country, too, if the
President could win re-election without having to take time off to
campaign.

My posts still contain a valid e-mail address. Let me hear from you.
Last I heard you were talking about community service &c.

Davoud

--
Sell GM for scrap metal. The country will recover and be better in the long run
without an anti-technology lobby to drag us down.

usenet *at* davidillig dawt com

On Dec 2, 7:34*pm, John Steinberg wrote:

Asking them to understand the sublime pleasures of the Mac is like
asking you to enjoy an evening of Governor Palin's elocution.

For one intensely pleasurable moment I thought you'd said
"electrocution".

I'm still at a loss to understand Trash's attack on the Bisque
mounting but will put it down to a lack of breeding. Or perhaps too
much of it ... in one small locality.

Hi all,

A friend on the Astro-Physics Users Group pointed me towards this
thread. Thanks for the very generous comments on my image.

On Dec 2, 3:12*pm, Thomas Womack
wrote:

The 1280x960 15fps camera can't have hurt - has the image processing
managed something clever like merging optimally-sharp portions from
multiple frames? *Or is 10" still small enough that the atmospheric
distortion in a lucky frame is uniform across the frame?

Yes, this picture uses multiple alignment positions done on many
regions in each of the 8 images that make up the mosaic. Stacking is
done on each point separately and then combined to form the sharpest
possible image from the collected data. It is much like adaptive
optics, or rather, adaptive processing. The larger chip size does not
help with this at all - it requires 4 times as many alignment points
as on a 640x480 chip size. There are about 120 alignment points
selected for stacking in each of the 8 images - so almost 1000
throughout the entire image. Each stack consists of an average of
approximately 120 frames (selected from a 650 frame movie.)

I'm not quite sure what the note at the bottom means; I interpret it
as eight pointings from each of which you take a thousand frames.

14.6 metre focal length onto five-micron pixels is I think (5e-6 /
14.6 * 180 / pi * 3600) 0.07 arcsec per pixel, which is substantially
oversampling the diffraction limit of a 10" mirror; about seven pixels
per kilometre on the Moon's surface! *I'm not sure if the image on the
Web is at that scale.

f14.6 is the native focal ratio of the 10" mak/cass. The focal length
for this image is 3.7 meters. My normal configuration for imaging the
moon is at f30. The seeing was not too good on this occasion so I
removed the barlow from the equation. The resolution on this image is
good (I think craters are resolved to about 1km though I haven't
checked closely.) The 10" will do better at 7 meters focal length -
resolving craterlets below 800 meters when the seeing and lighting are
favorable.

clear skies and best wishes,

Alan

Alan Friedman
www.avertedimagination.com

On Dec 2, 3:12*pm, Thomas Womack
wrote:
In article , Davoud wrote:
palsing wrote:
$10,000 won't even buy a really good mount these days...

Chris L Peterson wrote:
Fortunately, high resolution lunar imaging doesn't require exceptional
equipment. You could pull this off with a few thousand dollars. The
magic in this shot was in the image processing- what you could consider
post processed adaptive optics.

The 1280x960 15fps camera can't have hurt - has the image processing
managed something clever like merging optimally-sharp portions from
multiple frames? *Or is 10" still small enough that the atmospheric
distortion in a lucky frame is uniform across the frame?

I'm not quite sure what the note at the bottom means; I interpret it
as eight pointings from each of which you take a thousand frames.

14.6 metre focal length onto five-micron pixels is I think (5e-6 /
14.6 * 180 / pi * 3600) 0.07 arcsec per pixel, which is substantially
oversampling the diffraction limit of a 10" mirror; about seven pixels
per kilometre on the Moon's surface! *I'm not sure if the image on the
Web is at that scale.

Tom

IIRC from his article in S&T about processing, he breaks each area
down into smaller portions, then stacks the sharpest frames for each
smaller region, then merges the results into a final frame.