P3D Re: One-sided anti-newton glass (was Re: PHOTO-3D digest 3151)

[michaelk@xxxxxxxxxxx (Michael Kersenbrock)]

> Michael Kersenbrock wrote:
> 
> > The anti-Newton
> > glass has surface irregularities (small to you and me, but large on a
> > light-wavelength scale). That keeps the two surfaces apart.  So if the
> > glass is anti-newton'ed on only one side, it'll only work one way
> > (RBT's glass is this way I recall).
> 
> Yes, and what does one do to determine *which* side is anti-newton-ed
> after dropping a piece of the glass on the carpet?  It probably
> doesn't work like buttered toast where you can count on it landing
> a particular way.  ;-)  The two sides seem indistinguishable to
> the naked eye.

I certainly know one way.  While reviewing some slides this
evening to take to the CSC club meeting tommorrow, one of them 
I had mounted in an RBT mount with glass.  And it's 
newton-ringing up near the top edge.

So I guess the way is to mount and look for rings, and if one 
sees them, then "it's the other way".

:-)

Mike K.


> 
> Paul Talbot
> 
> 


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