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Re: [APML] PWPro 3.1 alignment methods
Hey Geoff,
--- astropix@att.net wrote:
> Any guiding/tracking errors
> in your original exposures cause problems for 'Refine'. Different
> exposure
> times and seeing conditions during individual exposures throw the
> 'Refine'
> function a curve as well.
There are always guide errors of some magnitude. Plus, I'm working with
a 40 second exposure and a 50 minute exposure. There are HUGE
differences between the alignment stars.
> If 'Refine' improves registration at a 2
> pixel
> radius, I then select 1 pixel radius and run it again... if not, I
> place them
> manually and let it be. If you start in 4 point/multi alignment,
> adding
> additional points is straight forward... if you start in 3 point, you
> have to
> reset all points, i.e. you have to start over in 4 point. Check your
> work
> with 'Absolute Difference'... sometimes only a small area will
> require
> additional points to improve registration.
All very useful and helpful.
Thanks,
Alan
=====
Alan Voetsch
critter12952@yahoo.com
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