From: "James Lerch" 
To: "Galogaza" , "ATM
List" 
Reply-To: "James Lerch" 


----- Original Message -----
From: "Galogaza" 


>
> At the beginning there was dilemma whether Carl's Couder
> or James Robo is OK. After really impressive set of tests
> ( I do not understand where from James has the energy he is displaying,
> perhaps he is  robot himself),
> the controversy was not solved.
> In James words "To hopefully solve this dilemma",  Bob Royce
was called
in.
> There are three possible outcomes.
> His measurements will ether confirm Carl's, James or none of them.
> If James "wins", " ATM optical testing using Couder
mask (which has ten's
of
> decades of history supporting it's results)" is in serious trouble ( And
> Richard will blow fanfare instead of oboe).
>
> If Carl wins, we are at the beginning in searching WHY robo
> Foucault is so (consistently) faulty.

Hi Vladimir,

First off, I'd like to push this discussion off Carl's shoulders and onto
Couder's, for one very simple reason.  Everything about Carl's optic
SCREAMS attention to detail!  I like lists, so let me list a few of the
reasons I say what I say.

#1 The packaging of the optic is impressive
    A) A nifty little hand made hard board 'Hat' lined with tissue paper
fits snugly over the face of the mirror, and extends down its side.

    B) This protective 'hat' is held in place with masking tape along the
edge of the optic.  Carl even goes so far as to clearly mark the end of the
masking tape, making removal of the tape damn simple!

    C) The optic and its protective 'hat' are sandwiched between 3 sheets of
closed cell white polystyrene.  In another bit of 'attention to detail'
Carl cuts one corner of the top layer of polystyrene so you can get your
finger between it and the box, with out damaging the box or your finger!

#2 Once you have the optic out of its shipping container, its obvious Carl
put a lot of thought into the selection of his blanks!  Simply put, its a
thing of beauty, not only that, its pristinely clean with NO crusty CEO
around the edges (something I've seen many times on most amateur and a few
commercial products)

#3 The Bevel is another item showing 'attention to detail!'  Its perfectly
flat, at 45 degree angle, with an incredible satin finish.  You might be
thinking "So what, its just a bevel", well its my opinion that
the quality of the bevel is often a pretty good indication as to the
quality put into the entire optical process, but I could be wrong :)

#4 The Optical Polish.  Many of you will not believe what I am about to
write, nor would I had I not seen it for myself.  When you aim a laser
pointer at the surface of Carl's mirror "You can not SEE the surface
reflection of the laser spot!"  You may see some dust on the surface,
but you can't SEE the surface, in all honesty my first reaction was
"this is not physically possible!"  After you scan the laser
around for a while, and you start to realize that "Yes, this is indeed
a level of polish I didn't think possible!" you start to think back on
all the mirrors you've tested similarly in the past.  Its at this moment
that I realized every optic I ever made, and every optic I've seen prior to
Carl's, were deserving of a sticker from Clausing that says
"Insufficient polish".   As testimony to
Carl's character, when I told him what an impression his polishing
technique made on our ATM class, his first words were "I can teach you
how to do that."

#5 Carl's mirror under the knife.  I'll be very honest here, the first thing
I looked for was his "Balanced diffraction edge", and plain as
day, there it was!  The surface of the optic was 'buttery' smooth, with
picture perfect ronchi lines. Carl's attention to detail continues with his
Couder testing methods, and I can say this as we were able to reproduce his
results over here in our lab, using the same methods he did.

It is for the above reasons (and more) that I say this is not "Carl
vs. Robo" but more precisely "Couder vs. Robo"!

Before I depart from this topic, let me offer one last item for everyone to
consider.  Carl Zambuto, a master optician with an incredible reputation,
has allowed myself (A mere amateur with limited experience) to examine and
discuss, in an open and public forum, the characteristics of one of his
sample optics!  Stop and think about this for a moment, as this is a
profound statement!  Regardless of the results of this experience, I am
humbled and honored to have had such a privilege!


> If neither Carl nor James are right, discussion will inevitably include
>  " Double Pass Auto Collimation Ronchi Test" credibility. (
I personally
> would appreciate greatly
> short explanation about this method or reference on relevant reading, is
> this method comparable to
> interferometric in accuracy.

For a primer on the test, I refer everyone to Mr. Royce's web page
detailing the test here:

http://www.rfroyce.com/testmethod.htm

As I understand the test it goes like this:

A light source is placed at the focal plane of the test optic.  As the
light leaves the source it is reflected off the mirror surface.  If the
surface of the mirror is parabolic, the light leaving the mirror will be in
the form of parallel rays (or flat wave front, depending on your point of
view).  This outgoing wave front will be reflected off a 'FLAT' optical
surface and returned to the optic under test.  If the optic is parabolic,
the now incoming parallel rays (or flat wave front) will be reflected back
to the focal plane, passing thru a Ronchi grating.  If the resulting Ronchi
lines are straight, then the optic is indeed a parabolic surface.  If the
lines are curved, the optic is not parabolic.

> I am ready to put more than my two cents in
> financing
> state of the art testing of the Zambuto mirror in order to have at least
one
> undisputable
> and rock solid result on this mirror for further reference).

Your not alone on this thinking!  ;)

Regards,
James

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