Re: [APML] IC1396 CCD with Schmidt-like FOV

["Mike Cook, AF9Y" <mwcook@concentric.net>]

Loke,

      Thanks for the insightful comparison.  I would like to further understand
your comments about the chromatic aberration of Nikon ED lens.  I have the
Nikon 180 F/2.8 ED lens and have not seen this problem.  Michael Covington
has also commented about the excellent chromatic aberration performance of
the Nikon ED lens here:

http://www.mir.com.my/rb/photography/hardwares/speciallenses/180nikkor.htm

      Besides, why should chromatic aberration of a lens be much a problem
anyway?  If you refocus for each of the RGB filters and register the images
with a program like RegiStar, it would appear to be a non issue.  What am
I missing?

Mike Cook
AF9Y


>From:           	lkt <tan@cox.net>

>............ The Nikon ED lens has noticeable blue haloing on the bright blue
> stars. Imagine how much nicer your image could have been w/o chromatic
> abberation. The blue custom scientific filter allows light into the CCD
> detector almost all the way down to 400nm. .................

Mike Cook, AF9Y
http://www.af9y.com
mwcook@cris.com




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