Re: ATM Central zone for Couder mask

["James W. Burrows" <burrjaw@halcyon.com>]

At 13:36 1999-07-06 +0700, Bob Prabowo wrote:

>Last night I read Tex book,2d edition (I bring the book to the office
>today:-) and on page 99 he says:

>"...By adding another suitable constant we can distribute the error more
>evenly, that is, ...For example by adding 0.015 we obtain..." (2)

>3.Could you tell me where Tex got the constant (in the second quote)
>from? Where did this number (0.015) come from?

Do exactly what Tex sez, "make the maximum [and minimum] departures...equal
[and opposite]":

knife           1.103   1.163   1.227   1.255
Hm^2/R  .005    .042    .090    .139
departure       1.098   1.121   1.137   1.116   (max + min)/2 = 1.118
-1.118          -.020   .003    .019    -.002

Then you can make the sketch that Tex does on p. 99.  I ran the "knife"
data through sixtests and it says it's a 1/5.1 wavefront mirror with Strehl
.945, tiny bit overcorrected with b = -1.07.  I'd either say it's good
enough or give it 30 s of 1/3 CoverC.

        -- Jim Burrows          phone 206.244.2933, fax .0294
        --                      mailto:burrjaw@halcyon.com
        --                      http://www.halcyon.com/burrjaw/
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