From: Milton Aupperle <milton@outcastsoft.com>
Date: September 26, 2010 12:22:05 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Jupiter Image
On 26-Sep-10, at 5:01 AM, albe albo wrote:
Hello Milton,
nice for a color camera.
I am not able to get good result with my DFK, i don't know why.
The details are always so messed up while with the DMK and the filters it seems to go better.
Yes, that's always been the case and has been discussed on this list many times. Bayer cameras are lower resolution (by about 50%) over Mono cameras. You mix adjacent color pixels together with Bayer filters to create the images.
Perhaps it is due to the possibility to process 3 or 4 different channels so the averaged result is better.
Yes.
However you also need good seeing for all 3 / 4 LRGB imaging sessions, so under my normally mediocre skies (>4+ arc seconds of motion) you get worse images that way. Fine details never show up anyhow except for maybe 1 or 2 nights a year.
Also with Jupiter's fast rotation, you have to shoot very quickly (or only a few frames) or you get rotational offsets between images.
30° above the horizon?
It was 20° when I started taking images and Jupiter only gets to 35° above the horizon here maximum, so I'm shooting though nearly 2x as much Air turbulence as other people.
Wow...i didn't remember you live so much at north.
Yes I'm at 50.5° N latitude.
Only a question : why did you leave the image so uncorrected regarding the white balance?
In my opinion it is pretty cyanotic.
I color balanced using the moon to "gray", when it was about 15° above the horizon. Which means it was dominantly red getting though atmosphere at that Altitude. By the time Jupiter got to 29°, the Blue and Green channels brightness increased.
I played with an automatic white balance (no other corrections) and perhaps the result is overcorrected but more similar to the visible Jupiter.
http://dl.dropbox.com/u/1094920/ASTRO/Jupiter/Jupiter_20100922_MJA-AWB.jpg
I left it as it's what I shot it as. I'm not 100% sure the real colors of most Astro Objects are either.
http://en.wikipedia.org/wiki/File:PIA02873.jpg
http://pds.jpl.nasa.gov/planets/images/browse/jupiter/jupiter.jpg
http://b4tea.com/wp-content/uploads/2010/03/Jupiter.jpg
http://www.solarviews.com/raw/jup/jupwsmap.gif
The current crop of images have Jupiter more red than I see it visually.
Later..
Milton Aupperle
