Re: Airy disc & contrast

[T3D John Bercovitz <bercov@xxxxxxxxxxx>]

> RE: John B. says he thought contrast was a function of aperture,

More precisely what I intended to indicate is that out of focus
images can be improved by stopping down and that this is a factor
in their contrast.  At least their edge contrast.  So maybe I
should have said acutance??  Some other word?

> I.e. slightly defocused enlargers center but "blurs" flare rings.

How are you using the word "center" here?

> I am sure by spot diagrams (which are representations of the 
> airy disc.) computers can jiggle curvatures and indices of glass  
> to get different Airy disc look!

Do you know what's juggled?  I have a simple program but it will
do spot diagrams.  (It's so simple you just say, "Run Spot, run!"
and it does it.  8-)

> I can see how Feynman was revereed as a great teacher and explainer
> as well as discoverer. He was most famous for 'stirring things up'!

I like his books too.  In person he was humorous and a bit loud and
I would say from personal experience that you didn't want to get in 
the way of his ego!

John B


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