200x pics of edges

H

HoB

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May 12, 2004
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I was promted to take these pictures by the recent scalpell thread. The pictures are not too good. The problem is that the camera has a limited contrast range and a limited depth of field. You get to see a lot more through the eyepieces than on the image. Anyway I though they might be interesting to some. They were taken on a Meiji Polarizing microscope with a trinocular head on a pixel link live feed firewire camera through a 10x objective lens and a 0.7x reducer, which amounts to roughly 200x Mag.

The first two pics are of a scalpell (Swann-Morton). One of each side. You can clearly see that while one side is finished with a polished microbevel the other one is not.

http://img197.exs.cx/my.php?loc=img197&image=scalpell8gl.png
http://img197.exs.cx/my.php?loc=img197&image=scalpell25si.png

The next two pics are of a razor blade (again both sides) (scalpell and razor blade both brand new). You can see that the razor blade is NOT polished (so I have to eat my words: I was wrong in the scalpell tread: There is a difference between a razor and a scalpell). But while the razor blade edge is resonably clean, the edge of the scalpell is rather ragged.
http://img197.exs.cx/my.php?loc=img197&image=razor7li.png
http://img197.exs.cx/my.php?loc=img197&image=razor23el.png

The next two pics are of a BRKT Mini-Canadian which comes factory wise with a convexed edge. The edge was polished on a nonparaille blue stone (2500 grit) and then on a Naniwa 10000 grit stone. It doesn't come out as nicely on the pics as thru the eye pieces, but the edge is MUCH more refined and the scratch pattern is much, much finer. This is probably my sharpest knife.
http://img197.exs.cx/my.php?loc=img197&image=minican6xj.png
http://img197.exs.cx/my.php?loc=img197&image=minican22ha.png

The next pic are of a Manix taken from factory to a Bester 700, King 1000, Blue 2500 and Naniwa 10000 stone. The edge looks even better than on the mini Canadian, but the edge profile is a little more obtuse so it is not quite as sharp as the Mini
http://img197.exs.cx/my.php?loc=img197&image=manixpol3xi.png


This pic is of a scratch pattern left by the Spyderco UF stones I made ten very light passes on the UF stones on top of the 10000 grit finish to see how they compare (they are not on the edge because I put a 17 deg edge bevel on the Manix and used the 15 deg setting on the sharpmaker), and you can see how the scratches of even the UF stones stand out against the 10000 grit finish.
http://img197.exs.cx/my.php?loc=img197&image=manixpol27ev.png

The last pic is of the factory edge of the Manix. You can see how the edge is very clean (in comparison to the razor and the scalpell) on a microscopic scale, but how wavy the edge is on a larger scale. I don't know if that is by accident or intentional. I was very surprised to see this under the microscope. These "dents" are invisible to the naked eye. Even knowing that they were there, I could NOT detect them even with a 10x lupe. So even though they appear really large here they are actually VERY small.
http://img197.exs.cx/my.php?loc=img197&image=manixnew9po.png
 
Nope. I can't see the pictures either. Please check the links.
 
may be because I wasn't finish typing? Damn two responses before I even finished :).

I just tried the links and they work fine. Will try on a second computer.
 
The links work fine for me (Mozilla). The "wavy" edge on the Spyderco is intentional. They explain it on their website. Even their non-serrated edges are still serrated.
 
just tried them on a different computer and they seem to work fine? Lemme know!
 
very cool... maybe that old junk microscope i've got lying around actually has a use now :D
 
Now I know how it looks like at micro level. You are a real dedicated knivesman my friend. Thanks for the pictures.
 
That was really interesting! Thanks for posting those.

Now where did I leave the keys to the electron microscope... :D
 
Cool Pix HoB! I've got a 10-30/20-60 binocular inspection scope that is fun to look at edges with. Too bad the trinocular version with ccd camera was so expensive or I could have a lot of fun posting micro pics. Someone did post some electron microscope pics once... can't remember where I saw them... maybe in the archives?
 
Really cool pics. Thanks for posting. Now you've got me wanting something higher than 3000x grit for my Edge Pro. :D
 
wonderful pics.....got any more for comparison?


would be nice to see the same knife at coarse, med, fine, polished.....
 
I gave you a rep point for the pix Hob.:cool:
Wish I could've given you more! Great pix and very educational.:D
If you ever get a chance try taking a picture of the chipped edge on a piece of obsidian. It chips sharper naturally than a highly polished edge on steel.:eek: :cool:
 
Thank you for all the nice responses! What I had planned was to take a few carpet knife blades and sharpen them to differnent grits. Might take me a few weeks to get around doing this though.
These carpet knife blades (essentially thick razor blades) are a lot easier to image since they are flat and I can easily fix them to the specimen holder. The images turn out to be a lot more comparable because the lighting never changes (which is a big issue since scratches appear a lot more pronounced when the light is perpendicular to them. They throw essentially shadows). In these pictures I tried hard to maintain uniform lighting perpendicular to the edge (along the scratches essentially), which I found to give the clearest image. The lighting was done with a fiberopic "snake light" and a little bit "background" light through the condensor.

Unfortunately, I don't have any obsedian...wouldn't really know were to get some aside from buying one of those stone knives which are a little bit out of my league price wise.
 
just for curiosity's sake, I'd like to see the edge of a disposable (shaving) razor blade new and when it gets dull enough to throw away.
 
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