RE: [APML] Sort of OT: New Meade Ritchey-Chretien

["Lane, Jason R" <jason.lane@navy.mil>]

Radu Corlan [rcorlan@pcnet.ro]

Hi Radu

>Field curvature is a first order effect in a cassergrainian (which means 
>that for a given secondary magnification, it will only loosely depend on 
>the configuration (SCT, classical cassergrain, RC etc). If the tube is the 
>same relative length as a SCT (which would imply f/2 primary and 4x 
>secondary magnification), it will have a little less curvature than a SCT, 
>but not a lot less). Besides, if it were a flat-field design, Meade's 
>marketing machine would let us know ;-).

>Nevertheless, the same affects a regular R-C, and this looks like a fine 
>telescope. Adding a field flattner is not that big of a deal.

>Radu

I agree completely, but it's the coma that makes the comparison spot diagrams look exactly like that of a typical Dall-Kirkham spot diagram with the effects of field curvature removed (ie spot diagrams are from points along the field of curvature).  Especially since they specifically called it a Cassegrain.

Cheers,
Jason
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