re: Re[2]: ATM Airy disk frustrations

["Tony Dunlap" <tdunlap@odot.dot.ohio.gov>]

Hi Dwight

How can you have a focal ratio less than one? wouldn't F1 be basically, half
of a sphere? I think I'm missing a fundamental here.

Thanks

===

Dwight Elvey said:

 Now an infinite mirror, would have no edge. It would
produce an infinitely small disk or an impulse spot.
Well in reality, we should be able to measure the size
of the stars disk. Something like a f/.000000000001 mirror
would be interesting. Can you imaging the field curvature
at focus for this? I guess there really are practical limits.
Dwight