[Raytrace] Dall Null

[John D. Upton]

Tom,

At 09:33 AM 9/6/2002 -0700, Tom Wicker wrote:
>I have noticed something else I don't understand. When
>you right click the surface data spreadsheet and scale
>to convert from mm to inch or vice versa, the P-V OPD
>in the wavefront graphics window scales by the same
>factor.  For example, if you convert from mm to inch

     Did you remember to go into the General Operating Conditions dialog 
and change the Units?  What OSLO is doing is using the new values to 
calculate the OPD but continuing to use the old units for the wavelength of 
light.  You are probably seeing the results for a 559" mirror.  This is why 
I mentioned before:

At 07:22 AM 9/6/2002 -0500, John D. Upton wrote:
>dialog box.  (Remember to set the correct units in General Operating 
>Conditions box before running a wavefront analysis.)  Of course, there are 
>other ways to convert

     I have seen no other strange results in using the Scale function as 
long I keep the units set correctly when doing wavefront analysis.

At 09:33 AM 9/6/2002 -0700, Tom Wicker wrote:
>the text window the P-V OPD and RMS OPD are slightly
>different (larger) than what is shown in the graphics window.

     I have wondered about this myself for a long time.  I don't know why 
this happens.  The differences are usually small enough that it hasn't 
prompted me to dig into the cause of the difference.  Any list members out 
there know (or suspect) a reason why this might be?

Sincerely,

John D. Upton
Georgetown, TX
<http://www.atm-workshop.com/>     "The ATM's Workshop"
<http://hometown.aol.com/RonWin20/> "Ronchi For Windows Home Page"