When R is attached to the edge of a workpiece, it may not be seen clearly.
You can see clearly by devising magnification, lighting, background.
| I tried to observe the edge of dry cell |  |
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1. Difference in depth of focus (compare at 80 times) |
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| Open the aperture | Close the aperture |
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| If you open the aperture, the depth of focus will become shallow and the edge may become blurred. | |
| 2.Difference in background color (compare at 80 times) | |
| When the background color is black | When the background color is white |
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| The edge may be blurred due to reflection of the background, reflection of the edge part due to lighting, shadows. | |
| 3. Difference in magnification | |
| The depth of focus also varies depending on the magnification. (open the aperture and compare) | |
| at 30 times | at 80 times |
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| Even with the same object, the edge may become unclear if the magnification increases. | |
