Re: [ATM] 8" F/4.2 progress

[Mike Lockwood <melockwo@uiuc.edu>]

Hi,

Richard wrote:
> Hi Mike,
> Thursday, October 27, 2005, 4:32:16 PM, you wrote:
> ML> Foucault probably gives the best balance of info of all three
> ML> qualities for a beginning mirror maker - at least that's what I think.
> 
> Others would argue that a simple mask and a digital camera or
> webcam, and Jim Burrows excellent Hartmann program is both easier
> and more accurate...

Hmmmm.... got the zip file, but I can't find a description of how to 
make the mask or what the software is actually doing, or what the 
light source is, etc.

My claim (see the quote above) was that Foucault gives the best 
balance of information with respect to surface roughness, overall 
shape, and edge condition.

Does the Hartmann test/program reveal surface roughness/dog biscuit or 
the edge condition?  A test for beginning mirror makers should show 
these conditions (in my opinion), or they will not know they exist!

Remember, I was talking about tests for BEGINNING mirror makers, not 
advanced ATMs.  Foucault requires less $$, equipment, and no computer 
- a calculator will do the trick.

Are we to the point where beginning mirror makers will be encouraged 
to use a completely automated test system?  Hell, we already have 
telescopes that find objects for you.  Let's just take all of the fun 
out of the hobby.... (OK, those who have built their own goto system 
and programmed their own control computer are exempted from my sarcasm) ;)

	Mike Lockwood




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