Re: [ATM] over&under correction.

["Mel Bartels" <mbartels@bbastrodesigns.com>]

> The under-corrected mirror would be easier to correct as you are
> mainly remving a little from the middle, rather than a little
> from everywhere but the middle. An over simplification, but


I've had good luck removing overcorrection by concentrating on the 70% zone 
with a little nod to the mirror center.  This can be controlled very nicely. 
If too overcorrected, then the 90+% zone becomes troublesome as its 
curvature is relatively steep, with resulting turned edge.  So that's why 
the generic caution to avoid overcorrection as the return to paraboloid 
often results in turning the edge.  However, as I say, for modest amounts of 
overcorrection, this generic caution can be ignored.

Mel Bartels 

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