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

Date: June 19, 2006 8:35:25 PM MDT

To: <Astro_IIDC@yahoogroups.com>

Subject: Re: [Astro_IIDC] Jupiter June 15

Reply-To: <alan@greatarrow.com>


Hi Phil -


By unfiltered I meant luminance through the clear or IR blocking filter, rather than 

through the RGB filters. Your seeing seems good enough for this to work well - it 

will provide more light for good signal/noise in your 6". Up my way the image is 

very turbulent using the full visible spectrum - I almost always get a steadier 

image by limiting the bandwidth. You can see the improvement easily observing 

the moon unfiltered compared to through the red or IR filter - the air is steadier 

down at these wavelengths.


best,

Alan


---------- Original Message ----------------------------------

From: Phil Houston <pkh111@knology.net>

Reply-To: Astro_IIDC@yahoogroups.com

Date:  Mon, 19 Jun 2006 17:34:01 -0400


---------- Original Message ----------------------------------


Alan,


Thanks.  I am using a  filter set from True Technology containing a  

clear, Ir block, R,G,and B filter.  I must use the Ir blocking filter  

in order to get a decent color balance so the Ir filter is used with  

all other filters.  So far it's been a convenience issue rather than  

a performance one. Removal would require disassembling the setup. I  

should try an unfiltered luminance, though.  What do you recommend?


I enjoyed your comparison between the 6" scope and 10" as it pertains  

to alignment and stacking.  Using a 2x Barlow increases the scale of  

my raw footage as does the 2x resampling before alignment so I feel  

that some of your and Milton's comments apply to me as well.  I have  

imaged Jupiter without the Barlow in place and produced good images  

but when upscaled they did not seem quite as detailed.  There are so  

many variables I get a little overwhelmed.  I do regret that I must  

over sharpen the images in order to pull out details.  It makes them  

look rather grainy and produces a nasty ring at the edge of the  

planet.  Any processing tricks to eliminate them??


Looking forward to seeing your latest.


Phil