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Re: [APML] 1805 Redo with Mike's technique



Roland Christen wrote:
 
<my snip>

<What you have there is classic lateral chromatic aberration (i.e. the blue image is slightly smaller than the red image). This means that the 3 colors don't quite register accross the frame. This may be fixable if you can extract the blue channel in Photoshop, increase its dimensions ever so slightly, and re-paste it back as a blue channel of the proper dimensions to fit the red channel. I notice that the red is also slightly different than the green. For a more perfect result, you might need to match the size of red to green and blue to green. >
 
 
 

For those of us using RegiStar, an easier way to do this is described at:
 
This technique has worked best for me with E200. Recently I've tried it with more blue sensitive films such as Fuji Provia 400F and hypered Kodak RG200, and it's somewhat less successful, but still worth the effort. 
 
John Boudreau
jeboud@mediaone.net
http://people.ne.mediaone.net/jeboud/astro.htm
----- Original Message -----
Sent: Monday, October 15, 2001 7:23 PM
Subject: Re: [APML] 1805 Redo with Mike's technique

In a message dated 10/15/2001 4:02:25 PM Pacific Daylight Time, philip@astrocruise.com writes:


blue
flaring on some stars cause by the lack of chromatic perfect-ness across
the spectrum.  


Flare is the used to describe extraneous light from poor baffling, shiny lens mount surfaces and internal reflections/ghost images caused by poor coatings. What you have there is classic lateral chromatic aberration (i.e. the blue image is slightly smaller than the red image). This means that the 3 colors don't quite register accross the frame. This may be fixable if you can extract the blue channel in Photoshop, increase its dimensions ever so slightly, and re-paste it back as a blue channel of the proper dimensions to fit the red channel. I notice that the red is also slightly different than the green. For a more perfect result, you might need to match the size of red to green and blue to green.

Roland Christen