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Re: [ATM] RE;1/8,1/16-1/20th debate.



----- Original Message ----- 
From: "Richard F.L.R. Snashall" <rflrs@rcn.com>

> Michael Peck wrote:

>> By the way the P-V error for the off axis field position above is high by 
>> about a factor of 2. How much did you pay for that copy of Zemax?
>>
>> Mike Peck
>>
>>
> Actually, take your pick:-)
>
>              on-axis P-V  on-axis RMS  off-axis P-V  off-axis RMS
>              -----------  -----------  ------------  ------------
>     ZEMAX     0.2511        0.0740      1.1877        0.2202
>     ATMOS     0.2469        0.0739      0.7201        0.1427
>     OSLO      0.2857        0.08224     0.5765        0.1099

Well, I did a little experiment, and I think I found something.

In Zemax, I have yet to learn how to tell it to just add 1/4 wave of pure 
spherical aberration.  Instead I just keep changing the Conic Constant, then 
refocus, and display the wave front map.

If I stick with the example 6" F/8 with a CC of -0.05 @ 550nm I can get two wave 
front results depending on how I tell the software to re-focus.

A) Focus for the least wave front error (which give a PVWF of 0.25)
B) Focus for the smallest spot size (which give a PVWF of 0.44)

So, I need to learn how to enter Zernike polynomials, or the equivalent, into 
Zemax.


Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
                                                           Calvin Coolidge 

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