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Re: [APML] Comet Bradfield Revisited
Hi Gary,
Those shots look fine! Perhaps you could try to increase contrast somewhat.
I would darken the sky and enhance the midtones.
As for DBE's tolerance, actually it isn't so critical. Just try to get a
high percentage of white pixels on the graphic plotted on the DBE window for
each sample, but ensure that small stars are well rejected. Pixels plotted
as white squares are being considered as background.
Use some samples on selected areas over the image, under different
vignetting/gradient conditions, to check that the tolerance value is working
reasonably well for all of them. For example, under normal vignetting, you
may use four or five samples over a diagonal of the image, from the center
to one corner, to test your tolerance value. Enough background pixels should
be sampled, but small bright objects must appear neatly black. Just a bit of
experience is required, but I see that you're doing it very well.
Juan
__________________________________________________________________
Juan Conejero, Pleiades Astrophoto Team
PixInsight Home Page: http://pleiades-astrophoto.com/pixinsight/
__________________________________________________________________
----- Original Message -----
From: "GARY HATFIELD" <Starmangmh@msn.com>
To: "APML" <astro-photo@seds.org>
Sent: Sunday, March 20, 2005 6:38 PM
Subject: [APML] Comet Bradfield Revisited
Hello All,
While going through some old slides I came across my only 2 shots of
Comet Bradfield from last April. They weren't very good as it was my first
comet. Between some morning clouds, being overexposed, and the glow of the
impending sunrise, I hadn't been able to do much with them last year. I put
them in PixInsight's DBE and was able to salvage them somewhat. I'm still
trying to figure out the tolerance levels for DBE. Anyway, it was
interesting to see the difference in the tail of Bradfield vs Machholz.
Taken between 4:30-5:00 a.m. est on 4/29/04...
http://www.starryestateobservatory.com/My_Homepage_Files/Page1.html<http://www.starryestateobservatory.com/My_Homepage_Files/Page1.html>
Gary
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