From: "mommoteandcoyote" 
To: "Richard F.L.R. Snashall" 
Cc: 
Reply-To: "mommoteandcoyote" 


Rick,

The only real problem I found with the system , was the increased  coma due
to the extreme shifting of the corrector from its optically pure position
at the radius of curvature of the primary mirror.


Coyot‚


----- Original Message -----
From: "Richard F.L.R. Snashall" 
To: 
Sent: Wednesday, January 22, 2003 8:32 PM Subject: Re: ATM An Old TMs Simple Query


>
>
>
> Matt Considine wrote:
>  > The back can be curved - it doesn't need to be flat.  In fact, if
> half the required curvature is
>  > put on both sides of the plate, you avoid having the back of the
> plate act as a flat reflector
>  > for ghost images.
>  >
>  > If I understand that design correctly, shouldn't the figure of the
> "secondary" spot have the
>  > same polynomial coefficients as the corrector surface it sits upon?
>  >
>  > Or are you putting two different curves onto the plate?  Wouldn't
> that be tough to make?
>  >
>
> The secondary side of the corrector in the example is spherical.  The
> Schmidt correction is on the front surface.  It is the primary that
> is also figured in the example.  If the separation between the primary
> and secondary is increased (to about 401.25 mm), the primary can also
> be made spherical.  This makes the EFL over 3 m.
>
> Rick S.
>
>  > Matt
>  > (who hasn't made a plate yet)
>  >
>  >
>  >
>
>
>
>

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