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[ATM] Gimbaled Secondary mirror
Don't have any experience with Dall-Kirkham's but, perhaps they are
sensitive to LSA/TSA due the intrinsic nature of spherical mirrors.
I've run this through OSLO and CODEV and I don't see any appreciable change
in aberration for the various back foci. There's nothing new about a movable
secondary, most large telescope use this method of focus.
PI has already spec'd the actuators for this mass and frequency and has
eaten most of my budget.
I'm just more interested in the gimbal; it may not be worth it due the small
angles involved and yes that 12 arc minutes to move half the focal plane.
>Did you know that the spherical aberration of a Cassegrain telescope
>changes substantially with the primary to secondary spacing? With an f/3
>primary and a secondary magnification of ~2.5, the primary to secondary
>spacing in our 20" corrected Dall-Kirkham needs to be set within about +/-
>1.5 mm to achieve best possible performance.
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