Re: [ATM] Lurie-Houghton telescope update

[Richard <cnc@cncservo.co.uk>]

Hi Ukyo,

Tuesday, November 8, 2005, 4:38:27 PM, you wrote:

UC> It is not easy for an ATMer to make and test convex surfaces

I have to disagree with that statement, especially with the LH
elements. The whole point of the LH principle is ease of
manufacture because for the two elements, each have a matching
convex/concave/ surface with the other. Plus, the surfaces are
spherical so no figuring and they refractive and so have
accuracy requirments probably a factor of 4 less than reflective
components. So, a hyperboloid convex reflecting surface -
difficult, but far from impossible for the amerture. A spherical
refracting convex surface?. Easy, anybody who has made a small
mirror could tackle it.

-- 

Best regards,
  Richard in the UK

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