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corrector design for RC

Started by aloha, 08/14/2005 11:00AM
Posted 08/14/2005 11:00AM Opening Post
Hi,

I'm interested in knowing design details about field flattener/corrector for RC, such as Takahashi's 250mm/F5 Baker RC. Can any one direct me to some sources?

Thank you very much.

Wei-Hao

Wei-Hao Wang
http://www.aoc.nrao.edu/~whwang
Posted 08/14/2005 09:09PM #1
Hello:
I couldn't find anything about a Baker RC on the web, so it appears to be a name Takahashi concocted on thier own. I read that the Pan-STARRS telescope is a modified Paul-Baker or Mersenne-Schmidt design. The Paul-Baker uses three mirrors, whereas the Pan-STARRS telescope uses two mirrors and a corrector lens assembly. I don't know if the Pan-STARRS telescopes start with a RC design or not, but it does make sense. Email Klaus, since I think he has done a lot of the Zemax analysis of the Pan-STARRS optical design. I did some reading in the IfA library about field flatteners and correctors, since I was interested (for a little while) in helping Nick with the optical design. This was several years ago, so I don't remember the references, but a search on the ADS should bring them up.
I have found some info on flat field RCs. Apparently, if the primary and secondary have the same radius of curvature, the focal plane will be flat. This has the disadvantage that the secondary mirror will be very large, typically near 50%. The Sloan telescope is of this design. In this case, the dominant residual aberration is astigmatism, which may be small enough to be ignored.

Cheers
Mike

P.S. I am not sure there will be room in my office for a 10" BRC! The 12.5" cassegrain is taking a lot of space. First light should be soon....