From: "Alan Friedman" <alan@greatarrow.com>

Date: April 24, 2005 1:32:01 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: jupiter with moons/ 4-19-05



Hi all - 


I posted an image to the files area of Jupiter taken last Monday night a couple of hours 

after my recent saturn image - also using an RGB filterwheel with my DMK21BF04 (the 

detail comes from the red and green filtered images only). It took just over 2 minutes to 

capture a set of three streams - but with seeing around 5/10 only about 380 frames from 

1300 were sharp enough to use for luminance. 


On the topic of alignment and stacking - this is a good example of why I prefer to select 

the alignment areas manually. This image is created from three sets of stacks aligned on 

the planet disk, ganymede and io. In two minutes there was little movement seen in 

Jupiter's features, but aligning on ganymede allowed some markings to be seen that were 

not visible in the images aligned using Jupiter's disk. Io shows considerable movement 

over two minutes and would have appeared as a short line if I hadn't processed a set of 

images centered on it's disk. 


I am really enjoying the filterwheel - with the fast response of the settings and prefs of 

Astro IIDC it works great even on Jupiter (it would have been hopeless to try this with my 

ToUcam running under BTV). I hope I'll get a shot at Jupiter in good seeing conditions.


best wishes and steady skies

Alan