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<p>[QUOTE=&quot;SuperDave, post: 2650411, member: 1892&quot;]OK, last visit with the 1910-S until I have it reslabbed.</p><p><br /></p><p>Here&#039;s an interesting conundrum: This new-style PCGS slab, which laughed at headlight polish and refused to lose its&#039; marks even under 2000 grit sandpaper, is <b>remarkably</b> sensitive to heat. Keep in mind, I&#039;ve polished both cars and 4x8 acrylic sign panels with a high-speed polisher; I&#039;m fairly well aware of what even cloth will do to paint or acrylic if you employ a heavy hand with a non-orbital machine. So, when I approached this thing with my Dremel, it was with the foreknowledge that it could probably burn pretty easily even with the soft felt drum I was about to hit it with. And I&#039;ve been cutting and polishing with a Dremel since, well, I wore the first one out and the second is fifteen years old now. Like that.</p><p><br /></p><p>And I still managed to burn the slab.</p><p><br /></p><p>The polishing initially went well; I used the second of the six available speeds on my tool and a brand-new felt polishing cylinder. Not just a near-flat disc, a cylinder of felt as tall as it was wide because I wanted to use the side to polish rather than the edge. That&#039;s one of the ways you avoid burning the subject. I practiced for a moment on another PCGS slab to ensure the amount of pressure I planned to use was appropriate, and it was. And it worked <i>wonderfully</i>. Took off the tiny scratches from the wetsanding in seconds, over the face of the coin. Then - after checking my work - I moved outward to the periphery where I hadn&#039;t expended any real effort with the headlight polish to remove the sanding scratches. I added the <i>slightest</i> bit of extra pressure, knowing the problem was worse, and it gouged the plastic <b>instantly </b>where I was a teeny bit heavy on one end of the felt.</p><p><br /></p><p>(insert extended period of profanity here)</p><p><br /></p><p>So now the slab has a 2mm x 15mm gouge up and left of the coin. It&#039;s shallow enough - I&#039;m pretty fast when the equivalent of saving my numismatic life is at stake, and I think I got the tool away in maybe two-tenths of a second - to probably be removable without trashing the slab, but, you know, I think I&#039;m tired of playing with it.....</p><p><br /></p><p>The gouge is not visible in appropriately-cropped images of the coin; it&#039;s a few mm above the top. For this last pair of images in the old slab, I tried something new. I X-Acto&#039;d a Nickel-sized hole in a piece of heavy matte black poster paper, and used it to eliminate any chance of the slab reflecting light into the lens from areas beyond the perimeter of the coin. I lit it with a <i>single</i> 45w R20 Incandescent flood at 10:00 and about 15 degrees from vertical, set white balance to Tungsten and shot it RAW. In RAW postprocessing, I finished correcting the color - it wasn&#039;t perfect - by manually manipulating the color temperature in Kelvin numbers until the poster board returned to black. The final setting was 3200k, just about right for an incandescent but telling for my camera, because &quot;Tungsten&quot; should be just about that number and it apparently wasn&#039;t. Down the road I&#039;m going to have to see what &quot;Auto&quot; does with that. I then circle-cropped the coin and filled the background with black, because some of the texture of the poster paper was interfering; it wasn&#039;t far enough out of the plane of focus to disappear.</p><p><br /></p><p>The final result is a teeny bit underexposed, because I like it, and therefore just a touch darker than in-hand viewing. However, the color is just about exactly - on my monitor - what I see with the calibrated Mk. I Eyeball under the loupe using my usual light. That was the goal.</p><p><br /></p><p>[ATTACH=full]586254[/ATTACH]</p><p><br /></p><p>[ATTACH=full]586255[/ATTACH]</p><p><br /></p><p>Oh, for the record, I shot these with the inexpensive El-Nikkor 75mm rather than my preferred Componon-S, because I needed greater working distance for the incandescent lamp. Total magnification was about 0.75x, well within the working capability of the lens.[/QUOTE]</p><p><br /></p>

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