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Old 16-08-2017, 12:55 PM
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nobby2 (Neil)
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Join Date: Mar 2014
Location: Norah Head, Central Coast, NSW
Posts: 150
Figuring Stage progress

Getting closer to a Parabolic 8" Mirror with the following comparison of the Ronchi calculator 85 grates per inch and a picture taken just using my iPhone. The first two compares inside ROC at -0.2 and the second two at Outside of ROC at 4.0. Pictures low quality
Click image for larger version

Name:	Inside ROC at -0.3.PNG
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ID:	217121

Click image for larger version

Name:	Inside-ROC-at--0.3.gif
Views:	68
Size:	133.6 KB
ID:	217122
I set my offsets on the Ronchi calculator at -0.3, -0.2, -0.1, 0.0, 0.1, 0.2, 0.3, 0.4, 0.5. The minus offsets return results from zones closer to the centre of the mirror and the positive numbers results from the outside zones of the mirror.
Attached Thumbnails
Click for full-size image (Outside ROC at 0.4.PNG)
17.9 KB105 views
Click for full-size image (Outside-0.4-ver-1.gif)
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