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Will this mirror focus light?

Started by tbennett, 08/09/2002 03:55AM
Posted 08/09/2002 03:55AM Opening Post
Hi All,

I've just acquired a grossly under-corrected commercial mirror that gives the Foucault test results below. Will be taking it to a star party this weekend to compare with a mirror from the same source that I refigured last year - and I thought that mirror was bad! - time to re-pitch the polishing tool.

Has anyone seen a commercial mirror worse than this one?

- Tom

TEXEREAU MIRROR TEST SHEET

Comments: Optical diameter: 16.2
Readings per zone: 1
Radius of curvature: 144
f/D: 4.44
Diffraction disc: 0.00011712

1 ZONE 1 2 3 4 5 6
2 h(x) 3.5800 4.8348 5.8253 6.6703 7.4197 8.1000
3 h(m) 2.5400 4.2074 5.3300 6.2478 7.0450 7.7598
4 hm**2/R 0.0448 0.1229 0.1973 0.2711 0.3447 0.4182
5 hm/4f 0.0088 0.0146 0.0185 0.0217 0.0245 0.0269
6 D1 0.2180 0.2360 0.2830 0.3270 0.4280 0.5000
7 D2 0.2180 0.2360 0.2830 0.3270 0.4280 0.5000
8 D12 0.2180 0.2360 0.2830 0.3270 0.4280 0.5000
9 D12 - 0.0898 0.1282 0.1462 0.1932 0.2372 0.3382 0.4102
10 Lamda c 0.0834 0.0232 -0.0041 -0.0339 -0.0065 -0.0080
11 Lamda f * 1e5 73.53 33.96 -7.60 -73.53 -15.86 -21.50
12 Lamda f / rho 6.278 2.900 -0.649 -6.278 -1.354 -1.836
13 u * 1E6 -10.21 -4.72 1.06 10.21 2.20 2.99
14 Wavefront -18.94 -22.56 -19.21 -8.28 -4.33 0.00
Reference parabola: y = -0.217853 * x**2 + 0.49017
passing through ( 1.50, 0.00) and ( 8.10, 0.00)

Maximum wavefront error = 1 / 1.0 wave at zone 2