From: albe albo <richter1956@yahoo.com>
Date: December 18, 2008 4:40:11 PM MST
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] New file uploaded to Astro_IIDC-Puzzling Problem
Thank you Milton and Alan.
You both know that i'm trying and trying to find alternate or complementary way for aligning/processing.
I applied de-warping to those mosaic images but when I did the first version of Copernicus something was strangely wrong and i didn't understand WHAT.
My eyes were puzzled by something unusual.
Since i'm pushing the focal to high values i'm noticing a strange blurring that it is not possible to improve with normal convolutions.
After exhamining carefully the images i noticed that the more contrasted features seemd to be doubled approx 5-6 pixels far from their originals.
I guessed that there was a "ghost" image that "directionally" messed up the overall sharpness even if the image itself is not clearly visible.
So i did an attempt duplicating the layer and subtracting a properly shifted layer (properly means experimenting the best position) set to 20% transparency on a black background layer et ..voilà i had the confirmation of the 2nd image exhistance!
Please check the attached images (zip file).
I suggest to select the images and open them at once in preview so you may perform a quick toggle between them.
The image numbered 1 is the original one the images numbered 2 are NOT sharpened or processed but the only process i did was the ghost subtraction, nothing else.
This mean that there was a single precise ghost messing up the sharpness.
The white arrows shows (on the images N.1) the whiter rims external to the craters that puzzled me.
I have this problem both with C8 and LX10 OTAS.
It is NOT due to processing (alignment, stacking or deconvolution).
The ghost is present in the movies too and appears as a quick shift of the feature due to the seeing but i'm wondering: why that quick shift moves straight and directionally?
Usually the seeing should move random generating a circle of confusion...not a ghost shifted image.
Maybe a partial deflection due to the red /ir filter into a not perfectly aligned optical path?
The OTA is pretty well collimated (the resolution of the details confirms that)
Now i will check again all my mosaics including The 4 rimae.
The improvement is very noticeable and i'm happy that i can recover some images that i considered as lost.
Someone knows why the ghosts do exist?
Maybe they are poltergeist craters?
Cheers!
Alberto
From: Alan Friedman <alan@greatarrow.com>
To: Astro_IIDC@yahoogroups.com
Sent: Thursday, December 18, 2008 10:52:10 PM
Subject: Re: [Astro_IIDC] New file uploaded to Astro_IIDC
Thanks for pointing out Alberto's post - I missed it first time around. That is an excellent image and the wide field adds much interest beyond the famous Copernicus. Great work!
best,
Alan
On Dec 18, 2008, at 4:43 PM, Milton Aupperle wrote:
Very stunning Copernicus and area, Alberto. Even though I'm on dial-
up at 2600 baud, it was well worth the 40+ second download time.
I really like the view around the "Domezilla" area to the west and
north. The ash deposits around it are really nicely defined (striped
area).
Thanks for sharing..
Milton Aupperle
(PS - it was -32° centigrade here last night and unlikely to get
above -25°C at night for the rest of the week).
On 18-Dec-08, at 10:24 AM, Astro_IIDC@yahoogro ups.com wrote:
>
> Hello,
>
> This email message is a notification to let you know that
> a file has been uploaded to the Files area of the Astro_IIDC
> group.
>
> File : /Lunar/081208- Copernicus- Region-V4. jpg
> Uploaded by : richter1956 <richter1956@ yahoo.com>
> Description : Copernicus, Eratosthenes & Friends...
>
> You can access this file at the URL:
> http://groups. yahoo.com/ group/Astro_ IIDC/files/ Lunar/081208-
> Copernicus-Region- V4.jpg
>
>