From: Willie Strickland <cwskas@earthlink.net>

Date: August 20, 2009 5:58:51 AM MDT

To: “A-IIDC“ <Astro_IIDC@yahoogroups.com>

Subject: confidence intervals & frame selection

I had some fairly good seeing last night and therefore most of the frames that I took ended up on the right half of the graph.  See the screen shot below for an example.  Using that example, a CI of 55% provides 501 frames, CI of 68% selects 194 frames, 80% selects 87 frames and 90% selects 41 frames.  I captured 1241 frames.  Here are excerpts from the logs.

At this stage of my experience, it is often hard for me to tell which provides the best results.  Would any of you care to comment on your reasoning?

=================== File:20090820_045333_U.mov #frames 1241

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: 1.60

Brightness: 608

Black Point: 0

Exposure: 16.67 ms

----Processing Movie: 20090820_045333_U.mov 1 of 1

Stacking : 8 Bit Movie

CI Cutoff: 90

Aligned Using: Luma Channel

Gross Alignment: Planetary

Pixel Alignment: Horizontal and Vertical Separate

Pixel Alignment Block Size: 96 x 96 pixels

Pixel Matching Tolerance :  6.00

Scale Frames by: 2 x

Frame Sharpening: Light

Gaussian Blur sharpness and alignment frames: Off

Sharpen alignment frames: Off

Auto Histogram Expand alignment frames: Off

HighQuality Bayer:Off

Auto Clip Area: Off

Adjust Pixel Comparison Area Brightness: Off

Remove Hot & Cold Pixels: Off

Binning Frames 2x2: Off

Averaging Images

Subtracting Background: Off

Sharpness Statistics: Min 4.862712 , Max 5.163545 , STD0.046297 , Mean 5.027537 , Median 5.027230 , Mode 5.042507, CutOff  Value 5.110049

Pixel Matching Value:  6.00

Main Image Centroid   X:641.5, Y:973.7

Pixel Area Two   X:624.5, Y:433.7

Stacked 42 out of 1241 frames