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

Date: July 23, 2006 1:54:04 PM MDT

To: <Astro_IIDC@yahoogroups.com>

Subject: Re: [Astro_IIDC] stacking and histogram questions

Reply-To: <alan@greatarrow.com>

Hi Eric - 

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

During my laborious processing of various streams, I notice that IIDC sometimes 

doesn't stack all of the frames I originally picked.  This has happened for both 

lunar and planetary sessions.  I noticed with Jupiter that I had to prealign in KIS 

first before IIDC would accept all of my hand picked frames.  With the moon, if I try 

prealigning first, in IIDC it doesn't align them well at all presumably because KIS 

allows the black edges to remain if it realigns a frame.  Is there anything I can do 

in IIDC to get all hand picked frames stacked?  I've had confidence at 0 (because 

they are hand picked) and I have tried various matching, but still a certain number 

of frames are excluded.  

Milton advice would be best here, but I think the setting to adjust is the pixel 

matching tolerance - set it to a lower value. This seems to occur in my stacks 

where the detail is very low in contrast (ie Jupiter at high magnifications) or when 

the image changes dramatically from frame to frame (solar images in poor seeing). 

If the confidence level is set to 0 I would expect a large number of frames to be 

dropped from the stack as you are including all the mush frames with the sharp 

ones and the pixel matching routine is going to fail with the mushy ones. 

Experiment with the selection region - try to find an area with contrasty features 

and it should help with the exclusion of frames.

I will look for a section of the alpine mosaic at full size. I think I posted the Plato 

section to the Astromart forum a month or two before assembling the complete 

mosaic.

Alan