This image shows the project pane,
where you can specify the parameters of your mirror and describe
the project. At bottom left is the list of all the measurements
you make as the polishing and figuring progresses.
This pane shows the details
of a single measurement. You can specify the date when you made
the measurement and describe what was done to the mirror prior to it. This
information is indispensable when learning the effect of various
figuring strokes. At bottom left is the list of all images that
comprise this measurement, along with knife offsets at which they
were taken and details of where exactly in the image the mirror
This pane is for setting
image parameters. The buttons along the top are used to align
the circular outline with the mirror in the image, and to
specify the orientation of knife edge. At right is
an entry for knife offset (in millimeters) and a checkbox for
excluding the image from the analysis.
This pane displays the results of analysis, in both numeric
and graphical formats.
- Numeric results
include common measures of mirror quality: Strehl ratio, RMS
and P-V deviation from parabola. They are calculated for
the entire mirror and the visible portion separately.
- Surface deviation
graph shows the deviation of the surface from the nearest
parabola in nanometers. This graph tells which regions
need to be polished away.
- Zone ROC
graph is the input into calculating the surface deviation.
This is what is measured in the traditional Foucault test
with a Couder mask, i.e. the distance between knife and
mirror where a zone darkens equally on opposite
graph shows the relative difference in illumination of the two
halves of the mirror as a function of knife offset. This graph
shows the results for a single zone, which is selected by
double-clicking on the
- Axis alignment
graph shows any systematic drift in asymmetry,
which indicates that the knife is not moving exactly along the
axis of the mirror. Misalignment results in systematic error on
the measurement of surface shape.
- Image contrast
helps adjust camera exposure and filter for the best
possible dynamic range. Knife alignment should be tweaked
to push the downward "kink" (around 30mm in the image) as low
as possible; measurements for zones inside of the kink are
Maintained by Dejan Vucinic <dvucinic (at) users.sourceforge.net>
Last updated on May 26th, 2002.
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