Re: [ATM] 10 inch mirror Foucault image puzzle

["Arjan te Marvelde" <arjan.te.marvelde@hetnet.nl>]

Dale,

What occurs to me, seeing it again, is that the features seem to have a
contrast that does not vary much over the surface. This is something you
would expect toe see if the mirror were spherical, but it is not. The best
place to see features on a non spherical usually is close to where the
dark/bright edges are, i.e. at radius of curvature.
The conclusion you could draw from this, is that the surface deviations are
either larger than the parabolic correction, or that we're looking at
something entirely different.

The image with the ke blocking most light reveals the areas with lots of
scatter, e.g. fingerprints. This would typically be caused by surface
contamination, or roughness. Could be etching from years of contact with
...?

Do you want to crack the problem, or use the mirror: why don't you just give
it a polish?

Cheers,
   Arjan

> I have had several replies but none that have helped
> nail the cause down yet for sure.
>
> I have taken more images that may help.
>
> http://home.comcast.net/~doeason/bvmirror/bvmirror.pdf

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