Etalon spacers thickness.

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Re: Etalon spacers thickness.

Post by swisswalter » Fri Apr 24, 2015 6:18 pm

Hi Antonello

thank you very much
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

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Re: Etalon spacers thickness.

Post by antonello » Mon Apr 27, 2015 10:27 am

Hello swisswalter

Thank you.
I read this your work: ... repair.pdf

Congratulations for your patience. Obviously you get more easily success sending all to Oliver Smie or buying a silica wafer with parallelism less of 10 nm. Here are two other suppliers with prices

You can try a microscope slide of 0.2 mm thickness, cutting many small pieces (2x2 mm).
To reduce the error of parallelism, you can put many pieces in circumference between the two glass (also 20 pieces) in order to average the error (not only 3-6 pieces) ...
I tried to play with this program ... -designer/

(that I have already mentioned) and I have verified that the correction of lambda / 100 of the optical surfaces is required. Unfortunately, the correction lambda / 10 is NOT sufficient.
The attached charts demonstrate this: NOT is possible, unfortunately , to achieve in own house a Etalon… :cry:
lambda-100.JPG (99.42 KiB) Viewed 1505 times
lambda-10.JPG (95.52 KiB) Viewed 1505 times


Re: Etalon spacers thickness.

Post by etatsolarchat » Sun May 03, 2015 1:59 am

In Bob's post I see they check etalons by looking at a light, anyone know exactly what light that is and what do they see by looking at it?? Thanks!


Re: Etalon spacers thickness.

Post by etatsolarchat » Sun May 03, 2015 3:35 am

Nevermind, it's just a hydrogen light, will have to get one..

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