WebThis is the slope criteria, Milles-Lacroix tornado or Danjon-Couder's first condition. Meeting these conditions calls for the mirror's surface to be accurate to about two-millionths of an inch, or one-twentieth of a micron (0.05 microns or 50 nanometers). The mirror's surface is carefully polished to achieve the required accuracy. WebThis is "Couder" mask I made to test the slope of each zone of the mirror. A smart man named Leon Foucault figured out how to use areas of a mirror and a Knife edge with some fairly complex math to determine the exact curvature of the mirror surface. I used a program thats a free download called FigureXP to enter my Foucault readings.

DAFT - Diffraction Assisted Figure Testing. - Astronomy

WebJul 7, 2014 · The Couder mask is a technical tool of cardboard, or other stiff and Matt material, that prepended to the parabolic mirror in construction to perform on it the … WebCouder Masks are the traditional method for zonal testing. They are quick and simple to make. edges of the openings show diffraction fringes while testing, and the mask hides a … They are used to create devices to mark mirror test zones: Couder Masks or … chili for 200

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WebDec 12, 2012 · Couder Mask with Instructions. Pinbout. 1.12K subscribers. Subscribe. 29. Share. 2.8K views 10 years ago. I'm making a couder mask to test a mirror Show more. WebThey are used to create devices to mark mirror test zones: Couder Masksor Everest Pin Sticks. How Many Zones? How many zones should you use? There is no set answer. parabolic mirror in the middle zone, and not split between two adjacent zones when an even number of zones is used. http://www.mirrorgrindingmachine.com/CouderPrn/ gps in a cessna 172