Thread: Economy digital scopes

Here is the first USB digital scope I purchased a few years ago. It ran on Win7 and depended on USB to power. That came unstuck for me when I upgraded to Win10. It supposedly zoomed (digitally) up to 600x mag. The specs say that was done with a 5x digital enhancement; so probably 120x optical magnification. Lowest mag was 25x. I think that all of the above images were done with it.

Old digital scope - 1-sm.jpg Old digital scope - 2-sm.jpg

Having been snookered with the Win7 driver that didn't work on Win10, I made sure that the next one I purchased could operate without having to be hooked up to whatever generation of Win'doze I'm using at the time, by having its own power supply, and independent storage of captured images on a MicroSD card that I could then transfer to wherever.

The CMOS on this one is 5MP and can produce still images up to 12M. The max digital zoom is up to 500x, but with 4x digital enhancement; so probably 125x optical magnification. It claims to have a high quality microscope lens. Magnification starts at a low 10x, which is useful, and I went with the LCD screen to make it easier for me to use, which it does a bit. The adjusting mechanism for the specimen table is a bit jerky for me at higher resolution, making it feel more like a consumable item than a serious piece of equipment, but that distinction has become increasingly blurred with anything you buy nowadays.

Newer digital scope -sm.jpg

With the incorporated LCD screen, the cost went over DW's suggested range up to A$100, but at the time the 5MP CMOS on this unit was good value for my purposes. It was at my price limit at the time, but 5MP CMOS units are more available now.

I have a couple of old lab microscopes (Zeiss and Olympus) and I have toyed with the idea of adding a CMOS to one of those to capture images, but as DW found, they are not a consumable product and move you up into a higher price bracket with their specialised C-mounts, etc. I expect that it won't be long before they will become available as ex-uni disposal equipment, which is where my two opticals came from.... Just had a look at digital eyepieces for optical microscopes and the consumer end is creeping up there too now, eg.

easy way to scale images of photos from systems, as at least as i understand it, more resolution with a good lens is a way to actually get more effective magnification whereas starting with a MP camera size and then zooming is going the other way (so if you have a 2000 pixel photo width at 200x optical, you should get about the same as 667 pixels at 600x optical, except the larger field of view makes context and acquisition of a spot easier.

One of the nice things about a metallurgical scope (not enabling!!) is the x/y table and then fine adjustment and coarse adjustment for those. IT's much easier to find a spot and then get clarity.

Better scopes than mine with better software, some approaching the cost of a car - can have better clarity, better color on the photos (I see blue all over the edge from the pen, but I probably don't have my camera software set right to pick it up, and the cheap scope is too little magnification to see it and too old and abused).

forgot the point - to scale what you're actually looking at, find a wire brush with the finest bristles you have (on hand), measure diameter with calipers (usually 4 to 7 thousandths or so) and take a picture. Then you have a good idea of photo scale and can start estimating things in microns (25 microns or a hair more in a thousandth). Can't really get exacts at reasonable magnification to the micron, but when you can take pictures you can start to see stark differences.

Three stones sold here as 12000 or 13000 grit (one bounces in ratings depending on who is selling it)

Kitayama (light green old tech waterstone) 12000:
kitayama.jpg

Shapton Cream (12000)- 1.12 micron rating - obviously not that closely graded, and the big particles do more work (this stone is actually very fast and practical, but it doesn't work like 1 micron grit):
shapton cream.jpg

And the sigma power 13,000 - 0.73 micron. Already an interesting spread just on the ratings:
sp13k.jpgk.jpg

It's obviously finer than the prior two by a lot, but it's proportionally slower than the shapton. The kitayama stone needs a slurry to work and is a pain without one. Not that it's a bad stone, it's just an inexpensive stone ($50 equivalent in japan) - the shapton cream is about the same price (despite a mark-up artist here in the states creating the idea that shapton stones should be really expensive, opening the door for shapton to create the overpriced glassstones - though they're good, their price makes no sense as I can buy enough graded alundum (that's closer than any of these stones) for $60 a pound retail. Enough to make a gaggle of stones finer than a shapton 30k as I can get that grit down to 0.1 micron if desired).


Anyway...



It's nice to have the extra resolution and magnification, but even with the bottom bar set by my oldest cigar scope, if you can get a picture where you see no scratches and no light reflecting on the edge, you're there.

Agree with Neil's assessment about knives, too - razors are similar - if you use a quick sharpening method and expect a very acute angle to be completely damage free, it's not going to happen unless you buff, and even then, a buffing wheel a bit stiff will damage the edge.

Another example of what you can learn here. I bought a lot of stones from japan. In them, I got many older synthetic stones that are unmarked, and a couple are real dandies (something has changed in the last 50 years or so in how much it costs to make really small alumina - it's far cheaper now).

Here's one of the stones that was functional but not that great. I'd say it's 4k-6k equivalent (I got these stones in groups of 15 for about $150 to get one or two stones in the group, so this is not really a loss to have something like this).

At any rate, the edge off of the stone:

white alundum soaked.jpg

This is probably better sharpness than most beginners get, because even though it's coarse, it does get all the way to the edge uniformly. Someone online may tell you "just strop with compound for 10 seconds"

white alundum improved 10 seconds of formax on pine.jpg

looks a lot prettier, but look at the actual edge. You can't really get top sharpness for stuff like carving tools and smoothing planes (that are finishing surfaces, not just any smoothing plane) with the edge still ragged like that. Translated, 10 seconds of heavy work on wood with the LV compound isn't enough to get through all of the damage left by the prior stone.

What about 4-0 seconds total?
white alundum - improved 40 seconds on pine.jpg

Now we're somewhere. Not only is the edge far more uniform, but this edge will probably last 25% longer (and be easier to push through wood). But, did you ever work something on a hard strop for 40 seconds? Nobody would do it, I wouldn't. So, it's not workable. You can't see any of the edge difference here with the naked eye or even a loupe, but the second picture would show a little bright stripe on even my cheap microscope. On a better hand held scope, you could get pictures closer to the metallurgical scope here (the fantastic white black contrast is part of the setup with a metallurgical scope, and that does make things easier).

What you learn from this is that trying to use this stone and then a fine buffing compound one after the other just isn't that great unless you're just removing the foil and leaving the damage. Fine for somethings, but you'll wish for better carving.

So, a different approach -
washita to work the back of the tool, and then a cotton buff on a wheel using linde A 0.3 micron compound. The buffing wheel is fast cutting compared to hand (90 feet per second or something of work, you just can't match it by hand, and the ability to conform to the apex and do more work just at the edge where the opposite happens by hand - when we sharpen by hand, the deepest scratches are at the edge where the abrasive makes an unsupported trip around the edge.

I'm sure the buffer ultimately would do this if used long enough to buff the whole surface, but we don't use it that long.

First the washita edwashita light pressure.jpgge -this is the light pressure picture from earlier - 10 seconds heavy to remove all wear from the back, 10 seconds light. It's touch sensitive (which is really nice once you know what to do with it) whereas alumina isn't quite so much.

Then, after the linde A buff (I had to make the buff bar of this stuff, but all it took was finding a throw away container , putting abrasive in it and then melting paraffin into the container and stirring. The abrasive is so small that it doesn't sink in the wax and remains uniform. In fact, all buff bars look like they're made this way as the bottom shows they're poured and the top is tapered narrower to let them out of the mould.
washita and linde A on buffer.jpg

(the lines that don't make it to the edge are washita scratches - the faint lines running the opposite direction are actually wax from the buffing wheel - in fact, you'll find it difficult with any tool that you've oiled, even if you wipe it with a shirt 6 times, to get all of the oil away from an edge - which has much to do with why oil stone users don't see much tool rust, even when they think there's no visible oil on a tool- even cleaned off on the flat side, one wipe from corner of a chisel where all of the oil wasn't removed, and that oil is rubbed on to the tool again).

This is one situation where my very cheap hand scope would fail, but winston chang (who guinea-pigged my unicorn method and took excellent pictures both back and bevel side with his phone setup) was able to get pictures that would've shown this.

Chisel tests

(This is in combination slightly less fine than my microscope pictures, but they color is nice and the setup will take pictures of things my scope won't, like rounded bevels. metallurgical scopes are intended to view flat surfaces and the light comes from one direct source, whatever is in line with it, that's what is reflected. softer lighting at various angles would help, but the depth of field if mine is too short and I won't be attempting that -as in, part of the bevel would be in focus and the rest wouldn't).

At any rate, this is a solution that I came up with in the search for laziness. $60 of linde A is enough for me to buff edges for a lifetime, the washita is a lifetime longer than our lifetime and the total cost of the two is about $110. The very edge that disappears into blackness is super fine and ever so slightly rounded, which ends up being an improvement - the apex doesn't break off early on as it will when tools are sharpened perfectly crisply.

The time to buff to get this edge finish is about five seconds - less than it would take to hand strop on bare leather.

But wait...there's more! (all learned and confirmed by microscope and experimentation)..

The buffer is gentler on the edge than hand honing, and this finish can be had on tools that are not as hard as we'd like - and suddenly by controlling the rounding, we can create things like $3 plane irons that will plane through silica without edge damage, and we can come back to the scope to confirm that there is none (such edge damage can easily be seen on the surface of a board, though).

This method can also work so little rounding that its' suitable on normal japanese planes (low angle with clearance issues). 8/10bu planes suffer a fight between clearance and edge strength in real life, and if you chip them and sharpen a normal sharpening cycle, you will be out 7 or 8 minutes minimum. It really stinks to sharpen a plane, chip it, plane again, chip it again and end up planing for 30 seconds and sharpening 15-20 minutes.

Gaming the setup like this, I can sharpen a 70mm japanese plane iron on an 8/10 bu plane in about 2-3 min minutes with a chip - a little less for normal wear. And the edge will be less likely to chip.

and one last bit learned -I didn't come up with the tip buffing routine with a microscope - I came up with it while using incannel gouges and only came back later to see what was going on. I thought it wouldn't be good for planing, but suddenly have now a bunch of softer irons that I had a distaste for that are wonderful to use. Their short life in the past was due to the fact that their apex didn't hold up - the softness itself only costs about 15% or so of edge life if you can avoid damage.

When I was testing my methods, I had a cocobolo board that I considered unplaneable in the past - you can see the silica in it - it winks at you.

The attached picture shows why it seems unplaneable - but the microscope allows seeing what's going on above and beyond just judging lines. The shaving at the top when the edge fails using a honing guide (just to gauge how well 32 degree edge will hold) was something like 70 feet planed - some small amount. The edge was failing for a while.

The bottom is at the same distance with a $3 plane iron buffed, but not even that sharp - the opposite side (bevel) was buffed, but the back left alone.

You can see the dents in the crisp apex iron, and you can see the light wear stripe and no damage in the rounded iron. This is nice visual confirmation. Now I have a way to plane the absolute worst of woods with the cheapest home depot iron I could find.

Unicorn Planing.jpg

I brought up the SEM images as they are the best examples that I can see in this day and time.
Leonard Lee was able to engage the co-operation of the National Research Council of Canada.
Now the National Science and Engineering Council of Canada.
As you all remember, LL was the grand old man of the Lee Valley enterprise and the pictures appear with many, many others
in his text on sharpening.

Originally Posted by Robson Valley

I brought up the SEM images as they are the best examples that I can see in this day and time.
Leonard Lee was able to engage the co-operation of the National Research Council of Canada.
Now the National Science and Engineering Council of Canada.
As you all remember, LL was the grand old man of the Lee Valley enterprise and the pictures appear with many, many others
in his text on sharpening.

I was thinking about this after my response - sorry to be direct about it. If I had access to an SEM, I'd use it, too - even if you don't need to see something, it's still interesting to see it.

I was hoping to be the cheap-man advocate for something useful to people to reduce level of work and cost, and I'm afraid even I'm making a case above for the ease of a metallurgical scope.

I don't think most of our spouses would agree with that!! but I found it necessary for being honest selling sharpening stones. I guess if someone was going to buy a shapton 30k, I would advise that they buy a metallurgical scope - that's what we refer to as a false dilemma, though (assuming someone can't be convinced out of buying one or another).

I made a video on youtube last year kind of heckling rob cosman without doing it directly, just because cosman touts buying sharpening stones and was saying "if you can stretch, the 30k is really worth happening".

It's 5mm thick and has abrasive in it that's very cheap to get by another means - one you can drop and not cry over. A literal $3 routine ($1 worth of PSA roll for grinding, a $1 flea market extra fine india stone and a $1 stick of clearance white alumina used on scrap wood - sandpaper used on flat wood planed flat, etc), results in this:

system edge.jpg

This doesn't look perfect when looking at scratches, but a closer look at the first thousandth or so that engages the wood, it's phenomenal - on the level of micron and submicron stones or loose abrasive used on a hard surface. It is a faster process than working through three shapton stones, and no flattening anything.

One place where an SEM is absolutely dominant is viewing bevel thickness - if someone was going to go down the rathole of covering bevel thickness and finish at the same time for some contest (or perhaps manufacturing and preparing manufactured razor blades, and examining failure), the SEM is the way to go.

I use a 10X geologist's loupe magnifier and improved my process with LED light.
It's been enough so far for me to judge a wood carving edge. What is the damage?
Should I begin with 600 or 800? Aging eyes have not been a help at all.

Holding a carving gouge up to the end of my nose then looking through the lens to see it has some risks to my beak.

The digital scopes would be a big step up for me.
I'd dearly love one day to repeat all that I do but with a DS.
If I saw a significant improvement in my judgement, I'd buy one in a flash.

I used research SEM and TEM for less than 10 years. Just a bit over the top here.
I wouldn't take a SEM if it was offered to me for free. The maintenance costs are substantial.

Originally Posted by Robson Valley

I wouldn't take a SEM if it was offered to me for free. The maintenance costs are substantial.

Thanks for confirmation of that. This is a steelmaking and engineering town (pittsburgh). It's not uncommon to see working SEMs offered for a reasonable price (but all of the ones I've seen are quite large in terms of space needs, especially compared to a compact metallurgical scope). I figured that the reason that they're not very expensive used is that there's potential high costs.

Here in the states, I hear farmers talking often about how cheap big trucks are, and they'll buy a semi tractor for something like $10k. Only to find out they can be through twice that the first year to fix things they weren't aware of. Their term is -"can't pass it up....cheap horsepower".

The older farmers who have their own fleet of trucks are pretty quick to point out the risks as they've experienced them and learned the hard way that using only the oldest and cheapest can sometimes be as bad as only buying the best brand new (and often the economy is somewhere between).

As far as a digital scope - I think I've taken hundreds (maybe thousands) of pictures of edges, but I never do it in day to day work. It's more like the case of listing stones and proving what they do (that's long in my past now), or refining methods. I don't check edges - that's the luxury of figuring out a method that's effort economy and easy to nail - so that the fiddling is while exploring things. Through my youtube channel, once in a while I get questions like "do you keep soft pine to test your edges on end grain" or "how do you test your edges after sharpening?" I don't, unless I'm bored or sharpening something questionable (like a soft knife), and then the issue is less about testing whether or not the sharpening was done well, and more about whether or not the tool or knife in question is worth bothering with.

Originally Posted by Robson Valley

I used research SEM and TEM for less than 10 years. Just a bit over the top here.
I wouldn't take a SEM if it was offered to me for free. The maintenance costs are substantial.

There are many small desktop SEMs available (that have lower maintenance costs than the fridge size machines of the past) that I would take in a heartbeat.
These are about the size of PC desktop and are commonly used for gunshot residue analysis.
BUT
Its unlikely they will fit a sample inside it bigger than about 100 x 100 x 40 mm
To fit something like a plane blade or chisel inside the sample chamber you will need to go up to a fridge size machine .

More great input there, thanks DW.

Love all those images of your sharp edges!

I went back to see if I could find a driver for my old cigar scope that would work in Win10 and found the following information.

USB Microscope Driver Downloads

The first two 'drivers' worked for me. I expect the inbuilt one Win10 would work with most scopes of that generation. It doesn't provide any control of the scope functions (eg snap and zoom), but you can see on the screen what is under the scope and chase up the images you have captured.

The other one I tried is the xploview driver and it has the advantage of providing a 'snap' button on the PC so you don't move the scope while taking an image capture.

I didn't try the other drivers. There are also where to find drivers for Mac, Linux, Chrome OS and Android. Running the scope off your mobile phone would be more convenient in the workshop.

My cigar scope came with a calibration ruler with the smallest size given as 0.076mm or 76μm. Here is an image of it (ie the width of the vertical line above the number) at the highest zoom magnification on that unit, supposedly at 600x.

WIN_20210221_09_32_05_Pro.jpg

At that resolution I don't think with my eyesight that I could see anything below 10 microns and definitely not below 5 microns. That's not good enough to see what is happening at the 1μm level that DW is recommending.

On max optical mag I'm not getting any better resolution of the 75μm line on my later scope.

Newer scope - Max optical mag - 75μm line.jpg

And the 4x digital zoom just gives a larger fuzzy image, which is no value at all.

Newer scope - Max optical mag - 4 x dig zoom - 75μm line.jpg

The limitations seem to come down to the optics of both scopes and the 5MP CMOS in my later scope is not giving me any extra detail over my earlier scope. Both are OK for what I use them for with turning tools as we are not grinding below about #300, as you will have seen from the earlier images I posted.

However, I'll do some more looking at what's on offer out there to see if better optics are on offer for a reasonable entry price.

Interested in knowing more about this but have no idea the scopes that you're referring to are what I was think about.
So I'll just include 2 different types of scopes from Amazon and seeking some opinions
1.Amazon.com
2. Amazon.com
Your evaluation would be most welcome.

Originally Posted by justonething

Interested in knowing more about this but have no idea the scopes that you're referring to are what I was think about.
So I'll just include 2 different types of scopes from Amazon and seeking some opinions
1.Amazon.com
2. Amazon.com
Your evaluation would be most welcome.

I'll leave DW to comment on those, other than to say you can pick up the 2nd (optical) type 2nd hand quite cheaply nowadays. The first one is more of what we have been talking about, but that one is closer to the upper end.

My next posting might be relevant to your decision, after DW has commented on my next post, if chooses to do so.

Originally Posted by NeilS

.....I'll do some more looking at what's on offer out there to see if better optics are on offer for a reasonable entry price.

What I have found is that it is only when you get up into the upper end CMOS units, which have larger MP ratings, that they start to quote micron sizes that can be seen through them listed in their specs. Here is a rough sampling.

MP	Down to	Pix resolution up to
5	2.2μm x 2.2μm	2592 x 1944
8	1.4μm x 1.4μm	3200 x 2400
12	1.55μm x 1.55μm	4032 x 2592
12	1.3μm x 1.3μm	4608 x 2592
16	2.85μm x 2.85μm	4608 x 3456
16	1.43μm x 1.43μm	4608 x 3456
21	1.3μm x 1.3μm

DW, what resolution do you get from your metallurgic scope?

Do we need to go up to those resolutions (anything above 5MP is getting very exy!) to be able to see what is happening at the 1μm level?

Sorry -slow to respond. I don't know what the max res is - it's either 3mp or 5mp - the scope doesn't say anything on it, but I use 1920x1080 as the default res. It's plenty big enough - as mentioned above, I kind of settled on it just based on what I can see and how much of the edge I can see. As in, it's nice to capture something like that picture iwth cocobolo above where you can see two distinct dings in the edge, but if the magnification is so close that you see all one ding and no good edge, it's hard to tell what you're looking at.

I'll respond to the question about the other two scopes on amazon separately.

Thanks for the heads up on the software - my newer scope (Which seems to look a lot like many) has much better led lighting on the front, and hooks up via USB (instead of having a permanent attached cord). I've never gotten it to work right, leaving me with the oldest one and another that's broken. They're so cheap that I figure maybe later I"ll figure one out - this gives that opportunity. The couple of free capture programs that I've found otherwise and expected to work with the new one strangely work only with the oldest one.

All that said, I think even the 75x or so that my first scope gives is worthwhile - most people will have bigger problems than the limits of the scope, and it's still true that once you see no scratches with it and no light from the edge, the resulting surface and sharpness are going to seem uncommon. Where it fails vs. my metallurgical scope (and a newer one probably wouldn't) is showing the difference, let's say, between 2 microns and 1 or something like that, but that's kind of insignificant. I still like it even though I can't get good pictures from it and have no great need for it. Since it's toplit, it's fun for the kids to to play with and look at things like tablet paper and labels (where you can see all of the dots instead of what looks to the naked eye like a solid line).

My comment about 1 micron is just basically that I was told that 3 microns will make a polished edge and nothing visible can be seen below them - that may have been a text book answer. Using graded diamond grit, that's clearly not the case. I have 1, 2.5, 0.5, 0.25, 0.1, then 5 and 10 micron grit all from the same company. The 1 seems to be just about where stray scratches go, and it's practically fast on cast iron (and super fine on wood where wood limits its ability to dig). So, what I can gather from that is that you can feel the difference between 3 microns and 1 in sharpness on a smoother - maybe only if you use one right after another, but you can feel it.

Then if you plane with both edges one right after another, you notice that the plane performs better smoothing and entering and staying in a cut at every footage measured, and then that a plane will stay in a cut in clean wood about 20% longer with the 1 micron edge than 3 alumina (the difference is actually greater with diamonds).

It turns out to be a handy bit of luck that where we stop noticing significant differences in effort is right around where the visible changes stop (but when you look through an SEM, it starts to become hard to tell what's significant, because you can still see scratches). I think the visible spectrum end is a good poor man's bar to aim for.

Steve Elliot tested abrasives all the way down to 0.25 micron diamonds and said that he continued to get improved longevity in high hardness irons (my words for the last part, not his - he was only using higher hardness irons at that point), but I don't know how much -it becomes impractical to me to add steps, and you can kiss the edge of a tool right off of a 1200 grit diamond with 1 micron diamond on cast and go right to work (removing back wear, too, of course). That's two steps, super fast, and with no visible scratches on the iron except for a few tiny bits where the diamonds have gone around the edge and left tiny scratches - there's nothing but super bright polish on the surface.

The surface is actually visibly brighter than a good oilstone (it wouldn't matter, but in an A/B comparison, it's bright - both are very bright surfaces if made uniform, though - mirror like without finish - one just more crisp than another), and the 1 micron diamond isn't sensitive to tool hardness like an oilstone.

Anyway - the same thing that I can't discern from SEMs is the case where the visible spectrum views things clearly. That is, if you have something like a 3 or 5 micron uniform aggressive scratch pattern, I can't really tell the difference between the two unless pictures are side by side, so in my view, the real value of the microscope is confirming no damages and figuring out how to get scratches to disappear at the edge (or at least leave a uniform edge). Same goes with medium stones. A fine india and a 1500 grit diamond hone can feel different in sharpness, but I can't see that much on the scope - they just look like rows of lines and the edge isn't perfect - you'd have to gain experience matching feel to picture to know what you're looking at.

kamisori: kamisori off of ohira.jpg
same after graded chrome ox on balsa (edge polished and rounded a little bit - less fragile and better starting point as hairs won't ding it - most of the lines are just a smear of oil, which I use on a balsa strop)
kamisori - chrome ox soft balsa.jpg

Everything that I needed the scope to do, like confirm kamisori edges (this is much like a knife - very thin edge, probably about 18 degrees, and fragile - to get them sharp, you first have to sharpen them like you would anything else, but then you have to do a lot of light pressure work to not damage an edge - this isn't a practical edge for a knife, because it stings you by being a fragile apex. When we use a razor for a while, this apex gets rubbed off and rounded over a little bit by linen and then the razor settles into being tougher and being a good shave for a very long time (perhaps 200 or 300 shaves with daily leather stropping and weekly linen). In a picture like this, the metallurgical scope becomes useful (an SEM would be good looking overhead, which the visible scope will not do), but again the danger of being able to see things that aren't that sigificant crops in. What punishes a razor user is failure of the edge (hairs doing the same dings you see in the plane edge picture in cocobolo on a smaller scale, but folding instead of breaking out), or failure of the edge to hold through sharpening and stropping. After that, if an edge can be established and survive linen, it's a good razor. There is a surprisingly large percentage of older razors that can't do that, and the confirms when you have a good edge but it then subsequently falls apart (because a bad temper, too soft or too hard, may not even survive the linen and you can't tell the feel difference between bad razor and bad sharpening - a view before hand saves wasting a lot of time resharpening a dud razor over and over only to have it fail. That can creep into being an hour or two of screwing around on something that really should just be sold as junk at a great loss or thrown away, or possibly saved to make a small marking knife later (they usually just need to be rehardened and tempered - but warping will negate their use as a razor after that). They can be broken off and ground into a useful knife.

So, yes, you can pretty much see down to 1 micron, but anything that can see no scratches in general (even if blurry) and no light coming back from the edge is good. Even a stropped razor edge reflects light (you can actually see that with a naked eye, and of course then with the scope).