Re: [APML] Well corrected Newtonian

[Aplanatic@aol.com]

Hi Tom:

> I presume this is a flat field design?

Yes, it has a flat field.

> This sounds somewhat similar to a Sky & Telescope article from about
> 1996...that was for an 8 inch hyperbolic newt with two element corrector.

Yes, that article by Paul was the begining, for me, in my long, slow --but enjoyable-- decline into the seedy depths of telescope design and fabrication.  <g>

My corrector designs are quite different from the ones that he used, but the basic idea is the same.  Has it really been 5 years?  Ouch, where does the time go, eh?

> I presume the color correction is also good for the near IR sensitivity of
> CCD's?

No, the design works well over the 400 nm to 700 nm band, and does not yield acceptable images beyond about 750 nm, in my opinion.  For CCD work, an IR blocking filter should be used.

Dave Rowe

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