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Posted by Ian McKernan on November 17, 2002 15:10:33 UTC

Hi all! Im figuring a 10 inch, 19mm thick, plate glass mirror, and discovering that i hate parabolising!! I'm a bit puzzled by the last set of results ive worked through. I started out using Tex for data reduction, and have been using Sixtests as well the last few rounds.

Anyhow, when i bung the numbers in, Tex tells me i have a 0.22 wavefront error at zone 4.

I bung the same numbers into Sixtests however and it tells me i have surface error of about 32nm. Call this a wavefront error of 64/560 and i get 0.11.

This is half what Tex tells me and makes me think there is something im missing here. If Sixtests is right then i really want to leave the beast alone as its giving me a Strehl ratio of 0.979 and RMS of 6.3 which i think are pretty good and the mirror also looks reasonably smooth. On the other hand if Tex is right then a little more polishing is required.

Im using a slitless tester and have selected moving source on both programs.

Any ideas / advice would be appreciated.

Seeyahs!

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