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Not very spectacular but very important progress over the last week:
I dug up the old test plate for the 16" Dall-Kirkham secondary mirror, with the associated tools, and reground it into a test plate for the CDK250 secondary.
I had to change the RC from 950 to 1110, which didn't take long. After the manual grinding I did about 4hrs of machine polishing followed by manual figuring. When the Ronchi lines were looking quite good, I set up the Bath interferometer to find a Strehl of about .8 Further figuring/testing got the Strehl ratio to .939 at which point I called it done.
Also I sent off a bunch of corrector lenses to Longman Optical to have them broad band AR coated. Fingers crossed.
The second picture is for Logan.
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