[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

RE: [APML] Registar Question



Title: Message
Hi Jim,
 
I've tried both Average and Median settings, but personally I prefer to only register and crop the images in RegiStar, then combine them in Picture Window.  RegiStar is absolutely great for registration and cropping, but the amount of control available in PW is far superior for the actual composite.  After registration, all you have to do is crop one image to match the other, and then you can open both in PW and use the Composite transformation without doing any alignment.
 
One advantage of doing the composite in PW is that you can use masks to avoid blowing out stars, bright objects, etc.  It's helpful for stacking meteor shots, for instance, since you can mask the meteors, and then do an Add composite in PW that only adds what's in the mask (the meteors) by manipulating the slider controls.  The core of M42 might be an example of doing a Blend in PW where you combine everthing but the masked core area to avoid blowing it out.  Sometimes I mask off the bright stars in one of the stack images to avoid blowing them up.  You can also try masking just the faint stuff and doing an Add or a Blend in PW.   Building masks is an acquired skill, but after you get the hang of it, you'll use them all the time for many operations.
 
BTW, thanks so much for the MI-250 manual!!
 
Sincerely,
Jon Kolb
Adventures in Astrophotography
http://home.datawest.net/jkolb/
jkolb@datawest.net

-----Original Message-----
From: owner-astro-photo@seds.org [mailto:owner-astro-photo@seds.org] On Behalf Of Jim Ives
Sent: Thursday, September 19, 2002 1:18 PM
To: APML
Subject: [APML] Registar Question

    I just purchased Registar.  Which of the settings is recommended for stacking scans to reduce grain?
Average
Median
Median/Mean
Overlay.....
Thanks for the help!
Jim Ives