Re: [ATM] Another flat-field anastigmatic aplant

["Richard F.L.R. Snashall" <rflrs@rcn.com>]

vladimir wrote:

>
>The arrangement is quite similar to Willstrop's variant of Paul-Baker in mirror placement. 
>The mirrors are somewhat easier to make, baffling is inherently easier due to configuration, 
>but it also puts limit of somewhat over 1 degree diameter to the field w/acceptable edge vignetting
>and up to ~50% c.obstruction.
>
Before it gets to one-fifth of that, the unvignetted diameter at
the hole in the primary is larger than the secondary size.  Just
curious: what would you suggest as the final size for that hole?

>An example is this 400mm aperture f/4.56 system:
>R1=-2400mm
>K1=-0.742
>to secondary:-1017.5mm
>R2=-550mm
>K2=0
>to tertiary:1600mm
>R3=-713.5mm
>K3=-0.373
>
>  
>
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