From: Ray Byrne <ray@in4media.co.uk>
Date: August 11, 2009 10:42:24 AM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Serenitatis notes
Hi Milton,
I think your comments here are extremely useful. I'm going to take a look at my settings to see if I've made some poor choices in preferences I've chosen. I know it's all there in your manual but reading a load of stuff can give one's brain a bit of overload sometimes so some hints from the guru are always welcome ;O]
On 11 Aug 2009, at 17:32, Milton Aupperle wrote:
Hi Willie;
A few suggestions from your capture and stacking logs.
From your Movie Log:
There's no need to do "Dark Frames" for lunar or probably planetary
either. The only time I do darks is if I'm shooting over 1 second
exposures or if I have a camera that has a lot of fixed pattern or
isochronous noise (i.e Unibrain, iRez etc.).
I likely would not use Sharpness Limiting at all. It was a an
"conceptual" idea when I developed it back 3 or 4 years ago, but I
don't think it's all that useful anymore. It can be fooled under high
turbulence conditions too and may accept blurry frames (well
actually, you have multiple ghosts of features present). Just shoot a
burst of say 300 to 2,000 frames and let the Stacking part determine
what is good or bad.
From your stacking log:
I think your frame sharpening is much too high, even with noise
reduction. Try turning the sharpening off or "slight" and definitely
turn off "Noise Reduction".
Turn off "Remove Hot & Cold Pixels" as it's unlikely to be of any use
for Lunar or planetary imaging anyhow, and just chews through CPU
cycles.
Your matching tolerance seems a little low to me at 4.0, however you
are getting about 50% of the frames in the stack, so likely you don't
need to change it. I normally run it at 6 to 10 here, but my
turbulence may be higher than what you had.
I'm not sure if scaling lunar images (3x in your log) really helps
much. It does chew through a lot of CPU cycles and I'm not sure you
wind up with a better image, except if you have really low turbulence
(GIGO principle). I do use 2x when doing Star / DSO LRGB images, but
that's only so that I can get a better match up of the color channels
when importing the L R G B images for combining and processing. I
sometime use 3x for Planetary images and then scale them back down to
1.5x after stacking, but only if the seeing won't permit me to go any
longer focal length. I did that for my Saturn image here:
http://www.outcastsoft.com/AstroImages/Saturn20090502MJA.jpg
Hope some of this helps..
Milton Aupperle
On 11-Aug-09, at 3:58 AM, Willie Strickland wrote:
> http://groups.yahoo.com/group/Astro_IIDC/attachments/folder/
> 1425995762/item/649358263/view
>
> 20090810_100552_U.mov_54LH-s.jpg -- Another shot of Mare Serenitatis
>
> =================== File:20090810_100552_U.mov #frames 75
> Monochrome Camera = Model:'DMx 21AF04.AS' SerialNumber: 0xFED2BB
> CCD Image Left: 0
> CCD Image Top: 0
> CCD Image Width: 640
> CCD Image: Height 480
> Gamma: 1.00
> Brightness: 180
> Black Point: 0
> Exposure: 16.67 ms
> Sharpness Limiting On: 1
> Dark Frame Subtraction On: 1
> Flat Frame Correction On: 0
> Invert Image On: 0
> Flip Horizontal On: 0
> Flip Vertical On: 0
> Histogram Expand On: 0
> Binning Off Monochrome
> Note: Moon, BG40 filter, .5FR, .6m scope
>
>
> ----Processing Movie: 20090810_100552_U.mov 1 of 1
> Stacking : 8 Bit Movie
> CI Cutoff: 54
> Aligned Using: Luma Channel
> Gross Alignment: Lunar - Solar
> Pixel Alignment: Horizontal and Vertical Separate
> Pixel Alignment Block Size: 96 x 96 pixels
> Pixel Matching Tolerance : 4.00
> Scale Frames by: 3 x
> Frame Sharpening: High with Noise Reduction
> Gaussian Blur sharpness and alignment frames: Off
> Sharpen alignment frames: On
> Auto Histogram Expand alignment frames: Off
> HighQuality Bayer:Off
> Auto Clip Area: On
> Adjust Pixel Comparison Area Brightness: Off
> Remove Hot & Cold Pixels: On
> Averaging Images
> Subtracting Background: Off
> Sharpness Statistics: Min 1.278378 , Max 1.353908 , STD0.014474 , Mean
> 1.329115 , Median 1.329420 , Mode 1.311422, CutOff Value 1.332331
> Pixel Matching Value: 4.00
>
> Main Image Centroid X:1369.3, Y:774.1
> Pixel Area One X:1343.3, Y:70.1
> Pixel Area Two X:1353.3, Y:54.1
> Stacked 30 out of 75 frames
>
>
ATB
Ray Byrne
in4media | graphic and website DESIGN
T: 01793 435704
