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Stargazing Network
George is looking at the surface of the mirror.  At this point, we have started the first stage (#120 grit) of fine grinding.
In this stage of the grinding, the material is being removed by the grit 'rolling' over the surface of the mirror. This results in the grit fracturing the glass and causing pits in the glass. To help document this process, John Mahony used an "eyepiece projection minus telescope" set-up as a photomicroscope and took a close-up of the surface of the mirror.  The dark spot in the center of the image is a pit left from the previous grade of grit.  The rest of the image shows the finer surface texture resulting from the newer finer grit.
His setup...
Of course, we all have to document the documenters....
Once the fine grinding was done, a pre-polish step was taken...