From: "James Lerch" 
To: 
Cc: "ATM List" 
Reply-To: "James Lerch" 


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Dan, =20

I'll take you up on your offer!  If your could independently confirm my =
following observations, perhaps we can come to understand the optical =
theory that must exist to explain WHY were seeing these results:

#1 Increasing Image Source brightness results in LESS total knife edge =
readings (Also test for the converse as well, all the while keeping a =
constant "shade of gray" null value)

#2 Lowest possible values for the "Shade of Gray" (keeping a constant =
image source brightness) results in LESS total knife edge readings. =20

Thanks,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and = coating site)
  ----- Original Message -----=20
  From: dan otto=20
  To: James Lerch ; atm_free{at}yahoogroups.com=20
  Cc: ATM List=20
  Sent: Monday, May 05, 2003 7:17 PM
  Subject: Re: ATM Robo-Foucault, Image intensity, and Changing knife =
edge readings


  James, I had similar results with my version of an automated tester.  =
I was testing a f7 8" mirror.  I found that that it was not as bad if
I = made a narrow slit but I was still not satisfied that the test results
= were valid.  They varied with the brightness of the led or the manual =
camera settings just like you described.  I put the mirror back in the =
scope and let the project rest so now I don't remember all my = conclusions
and what I was going to try next. =20

  I could resurect the project to help if you need me to try other ideas =
for you.  The test stand, camera, and platform are still setup.

  James Lerch  wrote:

    Can anyone help me explain WHY this is happening, or independently =
confirm
    my results on a mirror of similar size and F-Ratio??





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Dan,  
 
I'll take you up on your
offer!  =
If your could=20
independently confirm my following observations, perhaps we can come to=20
understand the optical theory that must exist to explain WHY were seeing =
these=20
results:
 
#1 Increasing Image Source brightness =
results in=20
LESS total knife edge readings (Also test for the converse as well, all=20
the while keeping a constant "shade of gray" null =
value)
 
#2 Lowest possible values for the =
"Shade of Gray"=20
(keeping a constant image source brightness) results in LESS total knife = edge=20
readings.  
 
Thanks,
James Lerchhttp://lerch.no-ip.com/atm;">http://lerch.no-ip.com/atmhttp://lerch.no-ip.com/atm">http://lerch.no-ip.com/atm;
(My = telescope=20
construction,testing, and coating site)

  ----- Original Message
----- 
  From:=20
  dan =
otto 
  To: James">mailto:jlerch1{at}tampabay.rr.com">James
Lerch ; atm_free{at}yahoogroups.com">mailto:atm_free{at}yahoogroups.com">atm_free{at}yahoogroups.com
=

  Cc:
ATM">mailto:ATM{at}shore.net">ATM List 
  Sent:
Monday, May 05, 2003 7:17 =
PM
  
Subject: Re: ATM Robo-Foucault, =
Image=20
  intensity, and Changing knife edge readings
  
  James, I had similar results with my version of an automated=20
  tester.  I was testing a f7 8" mirror.  I found
that that it =
was not=20
  as bad if I made a narrow slit but I was still not satisfied that the =
test=20
  results were valid.  They varied with the brightness of the led =
or the=20
  manual camera settings just like you described.  I put the mirror =
back in=20
  the scope and let the project rest so now I don't remember all my =
conclusions=20
  and what I was going to try next.  
   
  I could resurect the project to help if you need me to try other =
ideas=20
  for you.  The test stand, camera, and platform are still=20
  setup.James Lerch =
<jlerch1{at}tampabay.rr.com>=20
  wrote:
  
    Can anyone help me explain WHY this is happening, or =
independently=20
    confirmmy results on a mirror of similar size and=20
  F-Ratio??
  
  
  Do you Yahoo!?T=">http://us.rd.yahoo.com/search/mailsig/*http://search.yahoo.com">T=
he New=20
  Yahoo! Search - Faster. Easier.
Bingo.

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