I think it's about time you made a video, so we can see the light reflections and see how good/bad your work is.I’ve been thinking how to do this so that I can provide a visual. My stones are not perfectly flat, I decided to place a flat metal ruler on top of the blade against the back light instead. The light will come through between the blade & the ruler, revealing holes/low spots.
The first picture, ruler not in contact with the knife, lots of light coming through:
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Ruler on Shig., revealing low spots, very minor.
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Ruler on Shig. #2, contact moved closer to the edge:
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Ruler on Shig. #3:
Very close to the edge. The front is not a low spot, the ruler is off the edge at that spot due to the curve of the blade.
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As a control, here is my Shi.han against ruler:
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