Re: [ATM] [atm_free] Detecting Astig in Ronchi images

[Dale Eason <atmpob@yahoo.com>]

Yes I forgot to say the grating was 100lpi

I am posting a movie next.

Mel, you truly must be a master ronchi reader.  You
are the first to quantify it and orient it.  Your wave
rating is in agreement with my interferometer for
wavefront.  Your orientation is an exact match.

Everyone go back and look at
http://home.comcast.net/~doeason/Analysis_of_Davis.htm

The first 3d solid model shows it well.  I had not
discussed the orientation of that image.  The lower
right is the bottom of the mirror.  You can also see
it in the rotation series of blue images that Steve
Koehler did. That's how we know it is on the mirror.  

Congrats Mel.  Now you need to teach David how to see
it in when he gets the mirror back.  That is unless
there is something special about Oregon compared to
Minnesota.  Here the women are good looking and the
children are above average.  Perhaps there astig
vanishes.  If so I want to move there.

Dale Eason


--- Mel Bartels <mbartels@bbastrodesigns.com> wrote:

> > I'm trying to help David Davis identify astig in
> > ronchi images.  Can any of you see signs of astig
> in
> > these images?   They were taken every .05 inches
> > starting about .2 inside ROC.
> 
> 
> Yes, bad 'stig in the 30-70% zones, and some 'stig
> in the other zones.
> 
> 
> > If you can identify what it is that tells you. 
> Can
> > you also estimate the major axis and/or the
> magnitude?
> 
> 
> You didn't state the grating frequency, so it
> becomes even more of a ball
> park guess, but I'd say in the neighborhood of 1
> wave of 'stig.
> 
> As to the major axis, that's hard to say without
> rotating the mirror and
> comparing, but I'll guess an upper left to lower
> right major axis.
> 
> 
> 
> Mel Bartels
>  
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
_______________________________________________
ATM mailing list http://www.atmlist.net/