Herbert Highstone said:
Hello to all the folks--
.... I believe that it was also repolished and refigured, but I can't find the details of this work. Can another forum member tell us more about the optical side of this ambitious restoration?
This classic refractor, whose name is Rachel, is routinely available for public viewing sessions every Friday and Saturday night. I'm sure that this venerable instrument has planted the amateur astronomy idea into the heads of thousands of kids who have looked through the giant lens.
Best wishes from Herbert Highstone
I seem to recall reading about the lens being thoroughly cleaned, but can't recall that is was actually re-ground or figured. My optical mentor Bob Schalk who used to work at Tinsley had the measurements made on the lense, and it tested very well. He would regularly inspect and clean the lense after the restoration every so many months. However Bob has moved to Oregon, and is no longer doing this work, not sure who will be taking over.
With the fog below the telescope level, the seeing can sometimes get very good there. The 20" gave some jaw dropping views of the Moon one time I there. It was loafing at 800X and the detail just kept on going.
The new Chabot Science Center is a real showpiece now. The Telescope area seems almost like hallowed ground with the giant silver domes perched on the hillside overlooking the foggy San Francisco Bay.
I think the restoration was about 6-7 years ago ?? I only recently started going there when I started a little mirror grinding project. Have you been there since the restoration ?
Here is a picture of Rachel inside the huge dome.