From: Milton Aupperle <milton@outcastsoft.com>

Date: October 1, 2010 9:39:27 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Sunspot #1109


Hi Alan;


If the alignment object changes shape all the time, there isn't much one can do to try and align on it. It's basically "best fit".


TTYL..


Milton Aupperle



On 27-Sep-10, at 10:46 AM, Alan Friedman wrote:



Hi Milton,


I did, and it worked well - selecting both very bright and much darker frames that had sharp detail. It is the shape morphing that made stacking a poor choice for yesterday's data... stacking will work, but the resulting processed image shows less detail than a single good frame. In these conditions, working with a handful of good frames produces a better result.


best,

Alan




On Sep 27, 2010, at 12:11 PM, Milton Aupperle wrote:

Hi Alan;

If your shooting though clouds where the brightness is changing, AND
your tracking is good, you might want to try using the :

"Adjust pixel area brightness if frame brightness changes." stacking
option (see page 41 of the Manual).

I've used it for lunar imaging where brightness was changing due to
clouds. Even small changes in brightness can throw off the alignment
process.

TTYL..

Milton Aupperle

On 27-Sep-10, at 8:55 AM, Alan Friedman wrote:

>
>
> Hi Jim,
>
> Yes, I have too many telescopes!
>
> I combined two sets of two images at 50% and then blended the
> resulting two images at 50%. No different than your guess, but the
> fractions are easier to compute!
>
> There is a good amount of noise suppression even with such a small
> number of frames if the original capture was done with very low gain
> (possible when shooting the sun.) Stacking data when the solar
> details change shape from frame to frame just isn't very successful.
> Unfortunately I am back to the months where the sun is not out from
> behind the trees until almost 11am... mostly high turbulence by this
> time of day... a different set of tools is needed!
>
> cheers,
> Alan