Thread: Economy digital scopes

I can give my assessment of four cigar scopes - and a warning about one type. All of mine have been the fatter barrel type and not the ones that are thin like a pencil (though some of those may be OK).

The average cost of my three (this is over probably a 12 year period now, and the reason I have three instead of one is the first was broken by my kids and the second was for an old windows version and it wasn't worth the trouble to spend hours trying freeware software to see if it could be made to work with win 7 or 10 or whatever it didn't work on)...

...anyway, the average cost in US dollars with shipping was probably $15 each. They work great. They probably all had different magnification claims, but have two focal ranges - one is about 50 or 75x optical (don't know, never use it - it's more like an inspection scope level of resolution) and the other is about 100x. All said they were at least 500x, but the claims are based on a zoom in function from their software. The reality for anything other than viewing a spec of sand is that the photo resolution isn't high enough to allow that digital magnification.

I didn't get a good idea about where they were optically (pixel for pixel on a photo) until getting an indian metallurgical scope ($425 wth shipping, including a camera). The latter is absolutely not necessary for anyone and would only be useful to someone making tools or grading something (I was grading scratch patterns from japanese stones and reselling them).

So, when I mention a cigar scope - think fat cigars, like old cartoons, not cigarette or small slim size scopes.


The hand held scopes are pretty easy to use.

The other option is a dissection scope if you just want something easier to use than a high power loupe - they're usually around 25x and they will show you any scratches that you can't see with the naked eye - just not quite as well as a true microscope.

I've got a bunch of other uses for the metallurgical scope (like determining if an iron is folding or taking damage from wood and why, or if it's just low quality - this is only important if you're making tools or fixing tools for people). I'd stick with the fat cigar type if I was learning to sharpen. You can see so much more than a loupe and they barely cost more, and as mentioned in the sharpening thread, you can game sharpening methods to find a minute method that makes an edge last like the most cosmetically perfect 10 minute method you know of, or if you use a method like david charlesworths and are afraid to leave the guide behind, but want to, again, a 3-4 minute method can be replaced by a one minute method, and then you'll sharpen more often and get annoyed much less when you damage an edge, and then damage it again right after sharpening before realizing that the wood itself has something bad in it (silica, etc). Damage from silica will still probably show up with a 100x cigar scope just fine.

What does dullness due to wear look like?
https://i.imgur.com/J2OMH4M.jpg

What about silica? from a mineral inclusion in hard maple. These pits are about 3 thousandths of an inch, but when there are a few of them along an appreciable amount of the blade, the chipping and deflection itself creates enough bluntness to keep the plane from entering a cut, even if the rest of the iron is still sharp and undamaged.
https://i.imgur.com/HAMAR3Y.jpg (yuck!!)

You can actually use your hand scope to figure out a method that won't result in edge folding - I did, almost by accident, but without the scope, wouldn't have figured it out. I can plane cocobolo almost endlessly now with the cheapest softest irons I can find. perhaps 6 times longer in footage and three times that in volume planed vs. a high cost high speed steel iron just sharpened the same way you'd sharpen anything else.

I never had much luck with a loupe because my sharpening problems were smaller than the loupes could see and my eyesight at least up to this point (it's going now) was better than 20/20 - visual defects were fairly easy to see.

I snagged this picture off of an ebay.au auction - this type.

$18 AUD with shipping.

I'd try to find one that comes with software rather than saying you can download it, and make sure it has a normal USB connection for computer. Some of these will also work with a phone. They all will just show the visuals real time, or allow you to take pictures or small movies if you want to look across the edges.

The pictures are useful for you to compare edge quality and bust myths.

Japanese natural stones are much finer than anything synthetic, right? That's the myth.
Wrong - here's the picture of an edge from a $700 natural stone, few are this fine and the ones that are finer are only just finer. The only way to make this edge finer is to let the stone dry and burnish the tool on it. Not very practical, and I've never seen anyone in japan doing that.

Finest razor stone - jnat - slurry.jpg

What about learning the value of pressure and touch on certain stones? How about a washita stone using heavy pressure on the back of a tool:

washita heavy pressure.jpg

Not a very fine stone, huh?

But what about 10 seconds following using light pressure on the same stone to finish the edge (ghee, that's better than the slurried japanese stone above - the same japanese stone on clear water only slightly finer but a fifth of the speed and unusable):
washita light pressure.jpg

What about the effect of these sharpening media on various hardness steels - suddenly it's easy to see these things (and take pictures to compare). What you end up doing is experimenting intermittently, but running away when done with a highly effective sharpening method, usually involving nothing expensive.

Certainly, there must be some reward for spending all of that money on a shapton 30k, right? No, there isn't, and it may actually be slower, plus how will you feel if you drop it? (i've used the shapton 30k and had the gokumyo 20k, but graded at 0.5 micron).

How about an economy method to get in the ballpark of their sharpness, and no stone flattening?

$10 smiths "hard" (which is really just a soft arkansas stone) followed by autosol or dursol paste (can't remember - same manufacturer, same abrasive in it).

smiths 10 seconds dursol.jpg

by picture name, this is dursol. Because the soft stone is kind of coarse, it's fast. This combination of stones actually takes less time to use than a very fine stone, and if you focus on the very edge of the tool, this is a way to sharpen a chisel in about 30 seconds - one cheap medium stone and then a piece of wood with dursol on it- autosol would look the same - I have microscope pictures to prove it.

You can use the scope a time or two to confirm how little it takes to get the finished result at the edge and then not waste a bunch of time doing more work than you need to. If you sharpen a lot, this becomes a time savings, and not a time sink faffing looking at things.

I can get the same result as above with a $1 flea market india stone and a white stick of buffing compound that I found at sears on the clearance rack for a dollar, and again, it's more pleasant to use than expensive stones because the early work is done quickly, and I don't have to be precious with the later parts. If the wood gets contaminated, I throw it away and get another offcut. The microscope will prevent me from getting lost in myths about needing expensive something or other or thinking that this whole picture needs to look like a pure shine from corner to corner.

How good can autosol or dursol be? It depends on how you use it:
dursol on cast? - kind of rough - now you can see that it's made of approximately 3 micron sized alumina - but this can be gamed.
dursol on cast.jpg

Used on wood, the cutting action is almost as fast, but none of the individual particles can dig deep, and the substrate of wood won't be hard enough to damage the edge as long as the wood doesn't have foreign dirt in it.

Same abrasive, on wood:
dursol on pine.jpg

Even though I have dealt and have expensive stones (I dealt at break even so I could keep the ones I like, but also to give people in the open market an honest graded stone at about 1/3rd of the scam sellers who just get newly mind common stuff and mark way up), I can pretty easily prove why they're not necessary, and why the people selling them to you if they provide anything other than a collector's aspect or sort of a luxury viewpoint, they're taking advantage if you. At best, they have a lack of experience and are just passing along something a distributor has told them because it's favorable to them.

Abbe's Equation dictates the depth of field and the resolution of the optical system. You work with reflected light, not even transmitted light and the limitations are severe.
You ought to compare what you can see with your system with the National Research Council of Canada scanning electron microscope images in Leonard Lee's book. The wavelength of an electron beam reduces the resolution by a factor of 100X or more for vastly improved images that cannot be matched with simple light microscope devices.

Rig your own LED light for inspections. I use a silly little button light with one multiple LED device in it. Bench lights are off.
I get very hard and sharp shadows over scratches that way. That little light will out live me.

When you want to examine anisotropic materials such as crystals, you need to switch optical systems for polarized light.
This will require a pair of polarizing filters (busted sunglasses will do in a pinch.)

Originally Posted by Robson Valley

The wavelength of an electron beam reduces the resolution by a factor of 100X or more for vastly improved images that cannot be matched with simple light microscope devices.

I know what you mean, however just a clarification, resolution is the number of distinct lines/objects etc per unit length so technically an EM increases rather than reduces the resolution. One commonly used analogy is firing basket balls versus marbles at an object to map out its edges.

Thanks DW for all of your input; great value-add in those posts.

Am I right in thinking that those images you have posted are at approximately 150x optical magnification from your metallurgic scope?

What lighting have you used for capturing those images?

Do you have any examples of images from your 100x cigar scopes for comparison?

I'll try to find and post a few images from my digital scopes, which are nowhere as good as yours!

not sure why anyone would correlate practical experience and the need for SEM to look at edges.

I actually looked at used units while I was selling stones (not that expensive, but lots of space and what do you do if they break?).

Perceived differences in edges pretty much end when they can't be seen with a visible spectrum scope. as I recall, even a metallurgical 600x scope without a camera was only about $275, and it always works.

People think there's something about their sharpening that needs to be seen below visible wavelength or peddle rumors like "no abrasive below 3 microns can leave a visible scratch", but the reality is that if they're coming up short, it's because of something you can see. If a straight razor edge comes up short, it's due to a fault that you can see (or due to scratches left by a toxic stone where the scratches are too small for the naked eye, but very clear under a scope).

There was a big cheer for a guy who was showing edges being folded back and forth by a strop with an SEM (the "science" of sharp), but I can't think of any problem that i've had that the 100x digital hand scope wouldn't find. The metallurgical scope that I have now just makes it easier to get pictures. Getting pictures above 150x (at the 300 and 600 settings) actually makes the images harder to use for any practical purpose - the field of view is too small.

Originally Posted by NeilS

Thanks DW for all of your input; great value-add in those posts.

Am I right in thinking that those images you have posted are at approximately 150x optical magnification from your metallurgic scope?

What lighting have you used for capturing those images?

Do you have any examples of images from your 100x cigar scopes for comparison?

I'll try to find and post a few images from my digital scopes, which are nowhere as good as yours!

I'll see if I can find a 0.3mp image from the scope that I have working, but beware that it's the bottom of the barrel scope from a decade ago. The reason I don't have them at hand is because the software worked with another PC and my metallurgical scope is hooked up via printer type USB to this PC all the time. It's on the floor behind my desk for easy access.

As far as lighting, the metallurgical scopes are toplit - there is a separate halogen bulb (a common bulb) and a potentiometer on the light source, plus another shutter in line between the light source and the top tube (they both sort of do the same thing, but you can use one or the other to adjust light - for example if you're viewing something with deep scratches and something with a bright polish - the same light level will make a super bright picture with the polished surface (even that can be manipulated with gain in the included software).

I've seen hand scopes now that are more like 2 or 3mp and that's plenty.

Rather than just fishing out a random image, i have an idea. I'll take a picture of the same edge with both scopes (hand held old USB cigar scope, and one with metallurgical).

Yes on the magnification - 150x optical. The 300 and 600 are usable, but they show visible things too large with not enough other area, and it becomes tough then to see if you've really done a good job on the an edge. What we really want to see (scratches or edge damage in use) is best viewed around 150x.

(the black econo scope that I found on ebay earlier looks like it's 2.1mp image size. While even 0.3 shows you what you need to know, that's a welcome increase in image size (1920x1080). )

I believe my metallurgical scope is only 3 or 5mp, but it's the second camera as the first one isn't compatible with win 10 power management and won't connect on the USB.

Even a cheap top tube camera for a metallurgical scope is $185, so that was a bitter pill - that kind of stuff happens when you're buying something that's not consumer goods.

so, the only scope that works with win 10 (aside from metallurgical) is my oldest freehand scope - which I would guess now at more like 75x, but it's also 0.3MP and with a filthy and probably scratched lens

The color photo is the small cam (the hand held cam). The anomaly on the edge is from scratching the edge with a ball point pen - yes - just that will do that much damage.

The ridge on the edge of this iron is wear from planing with the cap iron set (cap pushes the shaving down, it bears on the edge of the iron. The length of the wear from the edge is probably about 3 thousandths of an inch for scale with the photo.

150x on the metallurgical scope. It's a joy for someone really wanting to sort little things out but with visible light.

All that said, even with the horrid older scope, your objective if you're really working fine is to see no scratches and no glint of light from the edge. This edge has "glint" because it's worn and rounded, so you can see that. There are definitely cases where you will not see that light with the naked eye, but it will be very reflective. I scaled down the metallurgical image in an editor to make it approximately the same size and remove the illusion that the difference in optical magnification is more than it is - part of it is the much larger image that the metallurgical scope will take.

The latter obviously will get clearer images (clearer than this, also) because it has a two way table and is sitting firmly on the ground.

ink pen 2.jpg

S20210219_0002.jpg

I believe the cheap scope with double the image size would functionally look like it could work twice as close, and a new one with a fresh lens and some kind of device holding it still instead of freehanding it would be worth tons, too.

don't discount holders for a good cell phone camera, either, at full resolution with good lighting. Some of these phones taking 20mp photos will probably see as much as some of the cheap scopes. The cost of specialty holders to use them can be $50 or $100, though.

To see what I use for a metallurgical scope, ebay 143148709317

Straight from india - that may seem like a risk (and it could be), but mine came "econo" free shipping and showed up from india in three days in perfect shape. I was shocked.

I have replaced the original camera on mine with - I think - 3MP (as i mentioned, the metallurgical top tube cameras are threated for a tube as shown, and they're ridiculously expensive for what they are - a USB camera that threads to a tube. really high resolution makes them go up in price fast - they're priced like digital cameras from 2002.

Originally Posted by Robson Valley

Rig your own LED light for inspections. I use a silly little button light with one multiple LED device in it. Bench lights are off.
I get very hard and sharp shadows over scratches that way.

I've done similar RV. Found a flexible arm desk lamp at IKEA that I can move about then set to get the best angle.

As you have observed, the image you are capturing is from the reflected light off the surface of the blade edge. An oblique angle light source helps to pick up the size of the scratch tracks, like looking at a freshly plowed paddock in the late afternoon sun light.

plowed-field.jpg
"Tractor Plowed Field And Arable Land"
by architectphd from FreeDigitalPhotos.net

LED light sources are a godsend for carving. At low oblique angles, the ridges appear which need to be kissed off with fine knife strokes.
Much in the manner of cutting a wood surface to finish it with a cabinet scraper. I use the kinds with no diffuser screen.
The big LED lights have some 44 devices and are rated at 45W. It's like noon in there!

From Abbe's Equation, resolution is a value 'd' which is the distance between two objects (lines or particles) such that they can be seen
as separate and distinct objects. A good clean transmission electron microscope runs with d = 0.4nm on a good day.

For optical systems, best rule-of-thumb is d = wavelength/2. Blue light is better than yellow light.

Here are some of my scope images that I have dug out. Where I have a 10x, 60x and supposed 200x mag of the same item I have put them together to show the additional benefits of having the 60x and 200x images.

This series was done during an investigating into the preparation of edges on woodturning scrapers with and without a burr.

Scraper - 200 X - before polishing.jpg
Scraper - 200x mag
- before polishing

Scraper - 200 X - polished to #12000 - before burr.jpg
Scraper - 200x mag
- polished to #12000
- before burr

Scraper - 200 X - burr honed off - edge view - arrow.JPG
Scraper - 200 X mag
- burr honed off
- edge on view - at arrow

Scraper - 10 X - #120 burr.jpg
Scraper - 10x mag
- with #120 burr


Scraper - 60 X - #120 burr.jpg
Scraper -60x mag
- with #120 burr

Scraper - 200 X - #120 burr.jpg
Scraper - 200x mag
- with #120 burr

The 200x image provided more information on the surface finish on the face of the polished scraper and also on the nature of the burr raised on a #120 diamond wheel. The 10x image provided minimal information on the burr and the 60x less than the 200x image.

Getting the straight on view of the edge was a challenge.

Another series, again to do with woodturning tools.

PnN Skew - X10.jpg
PnN Skew
- 10x mag

PnN Skew - X60.jpg
PnN Skew
- 60x mag

PnN Skew - X200.jpg
PnN Skew
- 200x mag

The 10x images provided almost no useful information over and above what my thumb could have told me. The 60x images had some useful information that could have been had with a 60x loupe. I found the (supposed) 200x images were more informative. My thumb would have told me that I had raised a burr, the 60x would have told me that the edge was dubbed before the burr, but the 200x showed the nature of the burr raised.

As you can see from the images, the lighting angles on the target area is important in yielding useful information.

And one more series...Crown Pro-PM 1in bowl gouge

Crown Pro-PM 1in bowl gouge - 10X.jpg
10x

Crown Pro-PM 1in bowl gouge - 60X.jpg
60x

Crown Pro-PM 1in bowl gouge - 200X.jpg
200x

I have a few of my kitchen knives off waterstones somewhere, but can't immediately lay my hands on them. I will add if and when I can find them.