From: Alan Friedman <alan@greatarrow.com>

Date: September 27, 2010 8:55:34 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Sunspot #1109

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

On Sep 27, 2010, at 6:15 AM, Jim Chung wrote:

Alan,

Very nice detail. Do you put the four frames into layers in PS and
then put them at 25% opacity to get an average effect before
flattening them? And I see you have a 6" AP refractor as well!

Jim

Quoting Alan Friedman <alan@greatarrow.com>:

> Hi Jim,
>
> I thought I was the only one crazy enough to be shooting the sun
> through the clouds... but at least I had enough sense to pass on Ha!
> 8^)
>
> I made this picture of solar archipelago 1109 by averaging four
> frames from one video in Photoshop. Sometimes that works better than
> stacking.
>
> http://www.avertedimagination.com/img_pages/solar_archipelago.html
>
> cheers,
> Alan
>
>
>
> On Sep 26, 2010, at 4:09 PM, jimchung2338 wrote:
>
>> Well, not the most exciting solar image but I did have to dodge
>> several hours of clouds this Sunday morning to get it. This was
>> taken with the improved 80mm PST mod scope that I had put together
>> this past winter. My AP Traveler is otherwise occupied so I sprang
>> for a cheap used $60 Celestron 90mm f/11 achromat, cut off 13cm of
>> it and installed an even cheaper all plastic Meade 2" focuser.
>> Despite humble origins, it works quite well. The addition of the
>> BF10 (BF5 is stock with the PST) I get a much larger fov and less
>> of the troublesome internal reflections. So I get the resolution of
>> an 80mm solar scope with the internals of a PST etalon.
>>
>> http://dl.dropbox.com/u/4852049/Sunspot1109.jpg
>>
>> Jim
>>
>>
>
>