From: Milton Aupperle <milton@outcastsoft.com>

Date: September 27, 2010 10:11:26 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Sunspot #1109

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