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Old 24-10-2016, 08:53 AM
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Merlin66 (Ken)
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Merlin66 is offline
 
Join Date: Oct 2005
Location: Junortoun Vic
Posts: 8,927
Guys,
I have no problems with the offset of the secondary mirrors....
The point I'm trying to make is that the shape of the ellipse cut from a conic is not the same shape as the ellipse cut from a cylinder.... they may "look" similar but in fact are not....

I think many secondary mirrors may be cast in a mould and some cut with cylindrical cutters from sheet glass.
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