Re[8]: [ATM] Chromatic effects visibility

[Richard <cnc@cncservo.co.uk>]

Hi vladimir,

Thursday, February 3, 2005, 1:41:23 PM, you wrote:

vs> That really looks impressive. I assume it is flat-field performance
vs> (Petzvals are similar to both, telescope and corrector, and astigmatism
vs> seems to be effectively cancelled). Being so effective and easy to make,
vs> these correctors should be accompanying every RC telescope.

Petzval radius is -2523.4498mm (-99.35") so not too far from
flat. The lenses shouldn't be too expensive, but they do need to
be 60mm or more diameter if they are to be far enough away from
the focuser/diagonal. AR coating is also essential I would have
thought, with 2 plane surfaces in the corrector.

-- 
Best regards,
 Richard                            mailto:cnc@cncservo.co.uk

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