From: Alan Friedman <alan@greatarrow.com>

Date: February 12, 2010 10:11:45 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Sun & Mars


Hi Jim,


There has been some conspicuous dust seen over the polar cap - I think much of what you've captured here is real - nice work!


The softness of detail in a 14 arc second disk at this magnification is a real challenge for image processing. Often it is possible to shoot at a shorter EFL and enlarge the processed image to achieve a very similar (and sometimes better) result. Is the presented image at 100% of capture size? It is just about identical to the size my 10" yields at f45. In a night of good seeing, that is about optimum for me.


best,

Alan




On Feb 12, 2010, at 11:23 AM, Jim Chung wrote:

Alan,

Thanks for giving it that master's touch, I can see new detail in the
polar cap!

I found that I had to go through about 200 sharpest frames and throw
out all the ones I felt were blurry. Some frames were so blurry that
I don't know what features on it were confusing the software. I guess
I never encountered this problem in the past because I wasn't shooting
at such extreme focal lengths.

Jim

Quoting Alan Friedman <alan@greatarrow.com>:

> Hi Jim,
>
> That is a fine mars image! I was going to comment that f62 is
> probably extreme... but you've pulled it off exceptionally well and
> with only 100 frames, the noise/detail quotient is very reasonable.
> The contrast of the albedo features is great and allows the
> atmospheric quality to come through. My eyes are a bit fried from
> staring at my own mars frames from last weekend, but I've tweaked
> your image just a bit to remove some noise and add a little
> brightness. The image is in the planetary folder in files just
> underneath your original:
> http://groups.yahoo.com/group/Astro_IIDC/files/Planetary/MarsFeb11_tweaked.jpg
>
> The sun images are a nice rendition as well - thanks for posting them.
>
> best,
> Alan
>
>
>
> On Feb 12, 2010, at 3:12 AM, jimchung2338 wrote:
>
>> After some helpful insight from Alan & Milton, I reprocessed the
>> solar images from the past weekend and they can be found here:
>>
>> http://tech.groups.yahoo.com/group/Astro_IIDC/files/Solar/SolarImages80mmPST
>> copyb.jpg
>>
>> Last night the seeing was somewhat better than average and I seized
>> this as my last imaging attempt with Mars this year. I used an
>> Antares 3x barlow and a barrel extension to yield a true f/62 or 12
>> m focal length image with my C8.
>>
>> http://tech.groups.yahoo.com/group/Astro_IIDC/files/Planetary/MarsFeb11.jpg
>>
>> Jim
>>
>>
>
>