From: Mark Gaffney <markgaffney@mac.com>
Date: May 8, 2009 4:32:36 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] definition of images..MAP & otherwise...
Thanks Milton, I`ll take all of that on board & try again. I am (& was) using version 4.04.00 & have now turned off "Adjust pixel area brightness if frame brightness changes". That particular movie was only 28 seconds long (63.2 Mb). It was done with a Vixen 2.4x extender barlow & I was getting lots of turbulence although earlier with the f 6.3 FR this was hardly noticeable. I`m often lazy when imaging the moon & only use Solar System Align on the CG-5 (no 3 star alignment, although PA was done at this stage I think) so I usually keep my movies to 1- 1 1/2 minutes long. For that movie & processing attempt I thought I selected 7 of the sharpest frames. My previous method was to not select any frames (I thought in that case it must use all available ones) & click "Done". My reading of the Manual is patchy & lots of things are forgotten, I`m sorry! Referring back to it whilst in the middle of an imaging session for particular selections isn`t ideal! If I can get my settings right for the moon with the Flea 2 I can save them I gather? Mark.
On 09/05/2009, at 7:46 AM, Milton Aupperle wrote:
Mark;
Your using an earlier version of Astro IIDC 4.x too (likely 4.02?),
and 4.04.00 is the current version I'd recommend.
The stacking log tells most of the story:
Why do you have
"Adjust pixel area brightness if frame brightness changes."
turned on? See page 33 of the manual for a complete explanation of
when to use it, as it primarily for DSO's. If your tracking is poor,
that will cause all sorts of issues with Lunar images for this
setting (it's explained why in the manual).
Thirdly, did your movie only have 108 frames? All your stacking it is
12 frames (in the first case), which frankly is very very few. I
shoot usually 800 to 2500 frames and then have it stack 70 to 300
(depending on the target, seeing conditions and gain levels).
Your selection areas are not really good and you tend to pick just
big white areas, which have no information to lock onto (white is
white). High contrast edges (shadows ) where there are black / white
areas with multiple features are much better choices. Always try and
pick areas with multiple things going on, as I'll illustrate below.
Using the same image, here are selection Areas I could have chosen
(assuming turbulence isn't too bad). Note that I avoided in most
cases just picking white blobby areas or black areas as neither black
nor white contain any information:
http://groups.yahoo.com/group/Astro_IIDC/files/Other/
MJA_Image_Selection_Area_Picks.jpg
I won't explain each one, but several have good common features:
Area 1 has a good dark edge and there are small craters with white
edges in the shadows to make it unique.
Area 2 has a white and black crater edge, but also is on a gray ridge
line too.
Area 4 has a very good hard diagonal white / gray edge, and the 4
dark craters make it unique along that edge. Usually I avoid long
straight edges unless I am selection one of the end points of it or
have other unique features with it too.
Areas 5, 7, 12, 16 and 17 has multiple Black and White crater edges.
Area 9 has multiple white, black and gray tonal features that are
unique.
Area 10 is at junction of two craters termini (looks like a anchor),
which gives us a good unique feature to lock onto.
Area 11 has a gray "notch" through the big white crater rim and also
has those small craters on the gray area. Note that I kept the amount
of pure white to minimum.
Area 21 is what I would pick if I was desperate, but it has the white
edge and then some white patches surrounded by gray. As long as
turbulence is not too excessive, it should be able to match that up
fairly well.
HTH..
Milton Aupperle
On 8-May-09, at 10:56 AM, Mark Gaffney wrote:
Hi Milton, I`m getting this for the snapshotted image preview window
after stacking & aligning;
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