From: "Russell Jocoy" 
To: greg.emery{at}mohawkcollege.ca, bader{at}hydroblendinc.com
Cc: atm{at}shore.net
Reply-To: "Russell Jocoy" 


>From: Emery Greg 
>Reply-To: Emery Greg 
>To: Byron Ader 
>CC: atm{at}shore.net
>Subject: Re: ATM Figuring problems
>Date: Mon, 21 Jul 2003 19:56:51 -0400
>
>
>Hi Byron:
>
>I had a look at the sketches.  I'm not very experienced with looking at the
>doughnut shadows.  I have no experience with an f/4.
>
>  My initial guess ( and that may unfortunately be the accuracy of it all )
>is that there is a central hill ( you said the knife was from the left,
>correct?).  The outside shadows at least look to be in the right areas.
>You really should make a Coude Mask (4 zones or so) and collect the data
>that way.  You can then analyze the data and have a more reliable estimate
>of the mirror surface.
>
>Personally, I would do the Coude mask and analyze the data before I touched
>the mirror again.  You can read about zonal testing in ATM 1, ATM 2 and
>Texereau.
>
>Anyone shed more light on this than I can (sorry for the bad pun)?
>
>ttfn
>greg
>
>----- Original Message -----
>From: Byron Ader 
>Date: Monday, July 21, 2003 5:53 pm
>Subject: ATM Figuring problems
>
> >
> > I just wanted to confirm my test results, I would hate to move
> > forward an
> > increase my problems.  Has anyone had a chance to review the
> > results of my
> > Focault test at www.astrothuse.com ?  If you had any feedback, I would
> > appreciate it.
> >
> > Thanks,
> > Byron
> >
> >
>



("atm{at}shore.net")

    I had  the same image in my Ronchi tests very close to ROC. I think you
need to polish more  and
test after  sessions to see changes. Don't think that you are in the
figuring stage when you are going
towards a sphere. If you have a raised or depressed center you have not
completed your task of creating
a sphereical surface. There is information on the net and in books on how
to get there from where you
are but most say , get the sphere and then figure... I would suggest to
polish more on your regular
stroke and rotate as before until the surface changes, if it doesn't than I
would check your lap for
closed gaps or irregular contact to the mirror's surface. Ain"t no big
deal the images you see through
your tester are just telling you the micro surface images, These can be
fixed and harmony of reflection
restored!! Keep polishing and look at the mirrors surface to see changes,
because it will.... Check your lap
give it some micro-fauceting (sp)...
      Russ Jocoy
("atm{at}shore.net")
>

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