Re: [ATM] Dobson mirrors and mirror test methods

["Nils Olof Carlin" <nilsolof.carlin@telia.com>]

Vladimir,

> Just to be sure.
> If inside-of-focus image has bright ring at 60% of its radius
> does that means that mirror has low  60% zone ?
> Is there really 1 to 1 correspondence over the whole mirror?

I haven't penetrated this much, but it would seem to me that it would mean a 
zone with a shorter radius of curvature than the rest, focusing a little 
closer than the average. I suppose this would correspond to a low zone...

This reminds me of the old Millies-Lacroix "trumpet" - a high spot on the 
curve didn't correspond to a high zone, but to a "tilting down" of the zone 
in question - you had to integrate the curve to get the profile.

Nils Olof 


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