Re: ATM : Additional Secondary for guiding ( was offcenter secondary)

[Andy Saulietis <iss@pvtnetworks.net>]

I wrote:

>Another possibility, for small fov CCD imagers, is to
>have the center part of the secondary 100% reflective
>(the part used by the CCD), the rest transparent &
>going to the tertiary. The transparent part could
>be a separate optical glass 'diagonal' to which the
>CCD secondary is attached. The advantage would
>be more light for the guide image, with a 'blind'
>spot in the center.

After a minute of thought, the transparent diagonal
is not needed, just the oversize tertiary concentric with the
secondary.


Andy Saulietis
ISS Enterprises
39 Silver Fox Trail
Mayhill NM 88339
505-687-3067 voice
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e-mail: iss@pvtnetworks.net