Re: [ATM] Malacara, Flats etc...

["Scott Milligan" <starzkey@charter.net>]

Bill:

As I approach the middling age of 50, I find myself reflecting every now and
then on those who have gone before and are no longer with us.  Tom Waineo
was my first mentor in optics, and your posting brought back some fine
memories of Tom answering the same greenhorn questions (mine) twice.  His
willingness to give freely of his energy and knowledge in support of others
is what I remember most about Tom, a colleague and a good friend.

Scott Milligan
 
 
-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
William Marriott
Sent: Wednesday, February 21, 2007 12:58 PM
To: atm@atmlist.net
Subject: Re: [ATM] Malacara, Flats etc...

Hello folks.

So if I am not mistaken, Ken may of been describing
the Ritchey Common test. If one does a search of our
archives, it will bring up several threads on the RC
test, including a copy of a long description of making
flats by Tom Waineo with both the ABC method and the
RC test.

http://astro.umsystem.edu/atm/ARCHIVES/FEB01/msg00617.html
When I had the prividge of spending a couple of weeks
working with Bob Goff (I always try to slip in his
name, gone, but never forgotten) and saw the RC test
put to the extreme.  Bob would rotate the flat even
more (I think it was +, would have to dig deep for my
notes from those sessions) which amplified the effect.

Bob swore he could test things to lamda/100, using a
tiny fizeau interferometer at the light source, but
traditionally one uses a knife edge tester. 

Bill Marriott
VA Optical labs




--- Chris Dalla Piazza <dalchri@hotmail.com> wrote:

> To avoid the need for a flat, I measure the
> difference between my tool and
> mirror using my spherometer and divide by 2.
> 
> I've been figuring that any inaccuracy due to
> imperfect contact such as an
> gap in the center or an gap at the edge would be
> small enough to ignore.
> 
> I'm interested to know, how does that sound to
> everyone?
> 
> -----Original Message-----
> From: atm-bounces@atmlist.net
> [mailto:atm-bounces@atmlist.net] On Behalf Of
> Francis J. O'Reilly
> Sent: Wednesday, February 21, 2007 11:11 AM
> To: Ken Hunter; Gregg Swanson; atm@atmlist.net
> Cc: deena@bestweb.net
> Subject: Re: [ATM] Malacara, Flats etc... topic was
> "They come through for
> me,again"
> 
> Ken,
> 
> Thank you for your thoughts. I have received
> considerable correspondence
> from various members of the list advising me that I
> don't need three blanks
> to make a flat. Indeed, one friend has basically
> advised me that using three
> blanks to make a flat is the old way to do it and
> tedious. 
> 
> I am now reconsidering the use of three blanks, but
> I still like the idea of
> having several flats for different purposes. I want
> one for a reference for
> a spherometer, although I am told that a flat is not
> necessary for that
> purpose, just a piece of float glass will do. I also
> want one for an
> autocollimator, which does require a flat. 
> 
> Regards,
> 
> Francis J. O'Reilly
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

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