Microscopes for edge inspection

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1315

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There was a past post on this somewhere, and many dismissed using visuals for inspecting the edge. I used a little $30 usb microscope. I learned a ton looking at my edge, especially when compared to Andrei's perfect Markin edge! Wow! The Markin gave me perspective, and some ideas for improvement when compared to my edge work.

Anyway, I'm glad I bought it. My mistake was only getting a 2 MegaPixel resolution. You can snap photos when looking at edges through the microscope. If you then open them, then maximize the screen size, then zoom, you lose clarity very fast with only 2 MP and it's kinda worthless. The unit I bought says 1000x, but it's nowhere near that. I think it's more like 40x if zoomed, and if expanded on screen maybe goes to 50-60x but again, gets fuzzy before that point.

Attached is a photo from my first microscope effort so may not be totally efficient
Snap_008.jpg
Here is a link to my $30 USB microscope that links to my PC screen via usb cable, or to my android phone screen via wifi:
https://www.amazon.com/Microscope-S...&qid=1676004691&sprefix=usb+mi,aps,718&sr=8-5
My question: What microscopes do you have that you'd recommend, what power or features are important, what is the price, and from whom? Is it worthwhile to buy better resolution for knives than the $30 picture above?

Thanks for your opinions,
1315...out.
 
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1315 said:
There was a past post on this somewhere, and many dismissed using visuals for inspecting the edge. I used a little $30 usb microscope. I learned a ton looking at my edge, especially when compared to Andrei's perfect Markin edge! Wow! The Markin gave me perspective, and some ideas for improvement when compared to my edge work.

Anyway, I'm glad I bought it. My mistake was only getting a 2 MegaPixel resolution. You can snap photos when looking at edges through the microscope. If you then open them, then maximize the screen size, then zoom, you lose clarity very fast with only 2 MP and it's kinda worthless. The unit I bought says 1000x, but it's nowhere near that. I think it's more like 40x if zoomed, and if expanded on screen maybe goes to 50-60x but again, gets fuzzy before that point.

Attached is a photo from me scope, from my first microscope effort so may not be totally efficient
View attachment 224868https://www.amazon.com/Microscope-S...&qid=1676004691&sprefix=usb+mi,aps,718&sr=8-5
My question: What microscopes do you have that you'd recommend, what power or features are important, what is the price, and from whom? Is it worthwhile to buy better resolution for knives than the $30 picture above?

Thanks for your opinions,
1315...out.
Click to expand...
I’ve seen something like this on Andrew Ren’s instagram (@xtol.ren). It may be more suitable for kanna though. Here’s a post that shows some of the optics he uses.
 
1315 said:
There was a past post on this somewhere, and many dismissed using visuals for inspecting the edge. I used a little $30 usb microscope. I learned a ton looking at my edge, especially when compared to Andrei's perfect Markin edge! Wow! The Markin gave me perspective, and some ideas for improvement when compared to my edge work.
Click to expand...

What did you learn?
 
I have looked into the same thing a few months ago, I can see the allure in knowing exactly what one is doing to the edge, and if there is a easy, affordable option out there, I'd still be very interested.

I asked on dpreview (digital photography forum) about this. I got quite a bit of helpful suggestions ranging from digital camera and phone conversion over to microscopes. Maybe there's something in there for you @1315:

https://www.dpreview.com/forums/post/66470345
If you're interested in background info, you can find a great explanation with examples about the challenges of using optical microscopes for evaluating edges: Science of Sharp - Optical vs Electron Microscope

I'm not saying it can't be done, but after reading Larrin's article, I decided that even results he got with lab-quality optical microscopes were modestly helpful at best. The electron mic photos are absolutely perfect, but I just don't have the countertop space to place one of those here.

With optical microscopes, it's not so much a problem of magnification, but also one of tackling threedimensionality and reflections of light. If one were willing to pursue this, i'm sure that a solution can be found. But I personally decided it was not worth the effort, both in money to spend on equipment and in time to figure out how to get this to work.

And yeah - please let us know what your findings and conclusions are.
 
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Captainc,
I drop the lens as close as possible, so it touches the edge. Then the grey dial to focus.
Then snap a pic, open in photo manager, expand to full screen on my laptop, tgen click to enlarge picture size.
 
1315 said:
Captainc,
I drop the lens as close as possible, so it touches the edge. Then the grey dial to focus.
Then snap a pic, open in photo manager, expand to full screen on my laptop, tgen click to enlarge picture size.
Click to expand...
On mine the barrel adjuster was the zoom, and focus came from adjusting distance between the lens and blade. Maybe that will work for you?

It took me a few tries to figure it out.
 
mengwong said:
an optical microscope is valuable when used to reveal edge-on reflections from an imperfect apex.
Click to expand...


^ This was my first thought ^. I imagine it could be quite an interesting way of learning more about wire edges and deburring.

TBH I'm not sure I could ever be faffed with looking at an edge under a USB scope. Though of course I do enjoy whiling away an hour or three looking at the surfaces of whetstones with one. But then who doesn't eh!
 
fs 4k scratch mid 1.jpg

The last 2 photos are of the same edge.
1. From the first photo, I learned "maybe I should not have asked!" Seems there is a blem near the edge. Sabi wabi!
2. Both pics above are 4K finish. The bottom pic, I paid attention more to parallel strokes, consistency, and lightening/tapering the pressure as I finished the progression. Much better! Next, on to 8K...
 
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1315 said:
Those are photos of the same edge.
1. From the first photo, I learned "maybe I should not have asked!" Seems there is a blem near the edge.
2. Both pics above are 4K finish. The bottom pic, I paid attention more to parallel strokes, consistency, and lightening/tapering the pressure as I finished the progression. Much better! Next, on to 8K...
Click to expand...
Yes, this is exactly why I have gone way too overboard on magnification devices. It's like hiring a little devil who says into your ear: "You still suck at sharpening."

Not that pleasant, maybe, but a great cure for arrogance.
 
I recommend looking carefully at the flatness of the apex on this progression:

Pre-microscope 4k Shapton Glass. I'm a rookie sharpener, and didn't spend enough time (or lighten pressure) as I progressed on the finer grits. Haphazard scratch pattern:
sm5.jpg



Post-microscope inspection with Shapton Glass 4k, more consistency and better progression, tapering off on pressure:
sm 4k rt3.jpg


Post microscope 8k shapton glass:
sm4 8k.jpg



And what have I learned?:
That the three-finger edge inspection is a real thing.
 
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