Where's the scratches? 640k finish

K

ksskss

Joined
May 25, 2006
Messages
262
Where's the scratches? This is a new use for my compounds - gem polishing! The brown stone is Topaz 0.5 carats, and the green stone is Cristinite 9.45 carats. The individual facets have been polished with a combination of 0.1 micron CBN (160,000 grit) followed by 0.025 micron Polycrystalline diamond (624,000) grit. No evidence of scratches! Closeup pictures taken with a Canon 1-5x macro lens of individual facets inside a light tent. Some of the matte finish is the reflection of the light tent on individual facets.

These are the same exact formulations that I use for ultra fine finishes of knives and razors.

1394087083-topazhalfcarat2.jpg



1394087099-topazhalfcarat5.jpg


1394087200-cristinite2.jpg


1394087280-cristinite10.jpg


1394087293-cristinite12.jpg


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Ken
 
Primarily for edges although you could do the whole knife if you wished. Here's a 640k knife edge using polycrystalline diamond on Kangaroo leather.

1401228_639010156149385_251602996_o.jpg


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Ken
 
...at first glance I didn't see the edge till I noticed the pattern on the card was wrong and the shadow. That is one nice mirror finish. How do you bring yourself to using such a nicely finished knife? I know it would pain me a bit to see it go away from using it.
 
Um, is this a trick question I hope? You won't see scratches from such high grit with 5x magnification.
 
I didn't think it was a trick question, but I guess it is. A 5x Macro lens is not the same as a 5x magnifier. Not even close. At 5x magnification, you wouldn't see scratches. Using a 5x loupe, the entire Large stone can be seen at one time. Using a 15x loupe the smaller half carat stone fills the screen. At the 4x setting of this Macro lens, cropping the 18MP image to the size in the photo at the highest magnification shown, you are looking at an image easily in the 500x range. A bit beyond the 'scope' of this discussion. Please review what a macro lens is. Most Marco lenses don't go beyond 1x. My lens is a Canon MP-E 65mm 1-5X Macro Lens.

Here's a picture of it with a couple of extension tubes:

1281061409-c4.jpg


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Ken
 
Here's a photo uncropped using this lens with a single extension tube of an insect eye for reference. Obviously not the same as a 5x loupe.

img_7645_1080x720_enh.jpg


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Ken
 
Here's a photo uncropped at 1k x 720 pixels using this lens with a single extension tube of an insect eye for reference. Obviously not the same as a 5x loupe. My pictures were shot at full resolution (5k on the long axis) and then cropped from that image.

img_7645_1080x720_enh.jpg


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Ken
 
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