From: Milton Aupperle <milton@outcastsoft.com>

Date: August 11, 2009 10:32:38 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Serenitatis notes

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