FW: [ATM] make ronchi grating

[mikell at optonline.net (Michael Lindner)]

On Monday 26 January 2004 05:26 pm, Mark Graybill wrote:
> I made my own Ronchi grating from the postscript code, it worked great.

Are there any concerns with (or has anyone experienced) curling of the 
transparency material? I would think that if the ronchi grating curls even a 
few thousandths of an inch the results would be off.

For that matter, to throw out an idea...the Mobsby grating uses curved ronchi 
lines to perform a null test on a parabola (or other non-sphere). Anyone ever 
consider curving the substrate of a ronchi grating to achieve the same 
result?

(warning, I have not done the math on this - just throwing out an idea).

-- 
Michael Lindner
http://www.starastronomy.org *** http://home.att.net/~mikel
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