Microscope Images Thread

[eKretz]

Ok fellas, let's try a thread specifically for microscope stuff for us magnification nerds. Anyone who doesn't see the point that's fine, but we (you know who you are ) enjoy this stuff. I'm hoping that @SliceOfLife and @alx gilmore and all you other microscope-loving guys will have some cool stuff to add too!

To get things started here are a few recent images. I posted a photo of the hair under polarized light, here's a comparison of a plain brightfield image of that same hair and the polarized one.

Brightfield, 500x optical

Polarized brightfield, 200x optical

Crystallized table sugar under polarized brightfield, 50x optical

Brightfield vs Darkfield series, same region of blade; first image 500x optical

~1200x optical, Brightfield

~1200x optical, Darkfield

Calibration slide at the last two images' scale, 10μ (.0004") graduations; take note the field will be wider than most, as this scope has super widefield eyepieces (Field number 26.5)

 

[stone and strop]

Love photos of edges, wish I could take and post them.
I'll be watching!

 

[timwcic]

Sitting with a bowl of popcorn waiting for the picture parade to come along

 

[JPO]

Does anyone have photos of edges were synthetic slurry have been used on higher grit stones?
I have used my 0.45 m shapton gs as a slurry stone on a hard jnat. This really increased the cutting speed, but the edge was terrible. Sharp, but rough. It seems like the edge is torn up, but it looks grate under poor magnification.
After using a natural nagura stone the edge looks worse, but shaves much better.
Do you need a SEM to capture carbide tear out, is this is actually what is happening?

 

[Herrenberg]

Does anyone have photos of edges were synthetic slurry have been used on higher grit stones?
I have used my 0.45 m shapton gs as a slurry stone on a hard jnat. This really increased the cutting speed, but the edge was terrible. Sharp, but rough. It seems like the edge is torn up, but it looks grate under poor magnification.
After using a natural nagura stone the edge looks worse, but shaves much better.
Do you need a SEM to capture carbide tear out, is this is actually what is happening?

What kind of steel is it? I ask because I may be confronting a similar dilemma.

I have a Titan (Taiwan) stainless steel razor that claims 70 HRC. After taking it through a sequence, I got a really good, comfortable, close shave out of it.

Recently I decided to thin it down to reduce the angle, and took it through a pure synthetic sequence, ending with the SG 30K. The bevel looks great to my eyes.

But the shave, while effective, is very uncomfortable. It's a hard thing to figure out. I've shaved directly off of the 30K before, and got an excellent, comfortable shave, but that was a Japanese Swedish Steel razor.

Reading your comment reminded me that when I honed this 70HRC razor before, I used a sequence consisting of synthetics, diamond/cbn, and, at the end, a couple of JNats, which really cleaned up the edge raggedness from the diamonds. Much more comfortable, night and day.

Maybe something similar going on? Some steels just not getting a comfortable edge from synthetics?

 

[eKretz]

There shouldn't be too many carbides in a good razor steel. Generally a plain carbon steel is best for razors. I haven't had much success with a synth slurry for finishing either. I have run into a lot of carbides in Pakistan steels and some Chinese steels too. I will see if I can get some images up of edges honed with synthetic slurry.

 

[Toro Blanco]

Daaaaaaaamn it! My nephew got a scholarship to SJSU and I was so impressed that I lent him my Leica for the next two years(I was not going to give it to him as it cost me over 2500$ and I love it! Lol), and then you start this thread!

The only other person doing it that I know is Alex G.

It is very time consuming but the knowledge you get is priceless. Peoples opinions matter but seeing is believing. Who care what that person "thinks".

Like my teacher used to say "Show me the data!"

Nice pictures ekretz!

 

[alex1921]

Keep them coming. I use a metallurgical scope and spend plenty of time staring at edges.

 

[eKretz]

Daaaaaaaamn it! My nephew got a scholarship to SJSU and I was so impressed that I lent him my Leica for the next two years(I was not going to give it to him as it cost me over 2500$ and I love it! Lol), and then you start this thread!

The only other person doing it that I know is Alex G.

It is very time consuming but the knowledge you get is priceless. Peoples opinions matter but seeing is believing. Who care what that person "thinks".

Like my teacher used to say "Show me the data!"

Nice pictures ekretz!

I wouldn't have any regrets there... Kudos for helping out your nephew! He must be a good kid if you trust him with that level of scope. And thanks!

 

[JPO]

What kind of steel is it? I ask because I may be confronting a similar dilemma.

I have a Titan (Taiwan) stainless steel razor that claims 70 HRC. After taking it through a sequence, I got a really good, comfortable, close shave out of it.

Recently I decided to thin it down to reduce the angle, and took it through a pure synthetic sequence, ending with the SG 30K. The bevel looks great to my eyes.
View attachment 1311170

But the shave, while effective, is very uncomfortable. It's a hard thing to figure out. I've shaved directly off of the 30K before, and got an excellent, comfortable shave, but that was a Japanese Swedish Steel razor.

Reading your comment reminded me that when I honed this 70HRC razor before, I used a sequence consisting of synthetics, diamond/cbn, and, at the end, a couple of JNats, which really cleaned up the edge raggedness from the diamonds. Much more comfortable, night and day.

Maybe something similar going on? Some steels just not getting a comfortable edge from synthetics?

The test i did was with an Hart Steel razor, but i think it applies to most razors, but more so with razor in the upper 60hr range. 70 hr, that seems way to much. You give up allot of fracture toughness, which leads to a brittle edge at that grit level.
I do not like to use slurry on anything above 1-3k. It just seems to eat up the edge. Jnat slurry on the other hand seems to work grate, even on synts.
I can take this razor up to 30k, but the stone needs to be clean.
I think this should be visible with a better scope. I know, i can just stick to what works, but i like to see what happens at the apex.
I got the same issue when i used an Venev OCB approx 5-6k in an progression. The edge looks good under magnification, but the fingerprint of that thing stays, and leads to an fragile uncomfortable edge. This is probably because of how deep the diamond cut. You get strain hardening effects deep into the steel, which catches up to you at the finishing stage. Again, grate looking edge, bad shave.
I also used some fine cbn in a jnat slurry. Again, the edge looked grate, but did not shave good.

 

[thp001]

Does anyone have photos of edges were synthetic slurry have been used on higher grit stones?
I have used my 0.45 m shapton gs as a slurry stone on a hard jnat. This really increased the cutting speed, but the edge was terrible. Sharp, but rough. It seems like the edge is torn up, but it looks grate under poor magnification.
After using a natural nagura stone the edge looks worse, but shaves much better.
Do you need a SEM to capture carbide tear out, is this is actually what is happening?

As a foreword none of what follows applies to plain carbon steels. If you're having issues and your razor isn't stainless might be something else at work.

I think the academic information on carbide "tearout" is very limited; but as far as what data is out there, it isn't something that happens during cutting at least. I can imagine though that as the surrounding matrix is abraded during sharpening carbides will eventually break away at the apex as sufficient surrounding material is removed but you're also exposing fresh carbides at the same time. It's the size of the carbides that is always going to limit keenness, even if you use an abrasive that can cut the carbides in any given steel, the softer matrix will always be eroded away at a faster rate so the edge will always have a microscopic "tooth" to it. For this reason carbon steel is still king for straight razors at least but there are stainless steels suitable for razors (AEB-L, Nitro-V come to mind) although none of these are used at a commercial level since straight shaving is so niche. Dovo and the other Solingen makers that have stainless models use an equivalent of 420HC series stainless (DIN 1.4116?).

 

[rbscebu]

What kind of steel is it? I ask because I may be confronting a similar dilemma.

I have a Titan (Taiwan) stainless steel razor that claims 70 HRC. After taking it through a sequence, I got a really good, comfortable, close shave out of it.

Recently I decided to thin it down to reduce the angle, and took it through a pure synthetic sequence, ending with the SG 30K. The bevel looks great to my eyes.
View attachment 1311170

But the shave, while effective, is very uncomfortable. It's a hard thing to figure out. I've shaved directly off of the 30K before, and got an excellent, comfortable shave, but that was a Japanese Swedish Steel razor.

Reading your comment reminded me that when I honed this 70HRC razor before, I used a sequence consisting of synthetics, diamond/cbn, and, at the end, a couple of JNats, which really cleaned up the edge raggedness from the diamonds. Much more comfortable, night and day.

Maybe something similar going on? Some steels just not getting a comfortable edge from synthetics?

As I stated before, my ACRO T.H-70 are all at about their factory bevel angle of the mid 18°. I have not yet tried to reduce the bevel angle on any of them.

I have no experience as to whether the T.H-70's will successfully hold an edge at a much more acute bevel angle.

@Herrenberg, give this a go. With my T.H-70's I would set the bevel on a 1k synthetic and finish the bevel on 4k synthetic, all without slurry, running water only. From there I would refine the bevel on lapping film up to 1μm and then finish on 0.5μm, 0.25μm and 0.1μm diamond pasted balsa strops. Don't forget the short X strokes. That's what makes the edge smooth and comfortable over the skin. After a bit of work (laps, not pressure, they're hard) I get an edge/bevel that gives my a close, comfortable, smooth shave, equivalent to what I get from my HCS German and English blades with bevel angles of around 16° (all honed in a similar fashion to the T.H-70's).

I feel that until a blade with a more acute bevel angle than my current T.H-70 can give me a noticeably superior shave, I'll keep my T.H-70's pretty much as is.

 

[eKretz]

Personally I don't worry too much about the bevel angle...I believe that obtaining a narrow apex width and making sure that there's no wire/foil edge to quickly fail are way more important. I've had plenty of comfortable shaves with a 30° pocket knife! Narrowing the bevel angle to any less than needed is only going to hurt durability in my opinion. I tried going under 15° once on a HSS razor and it did not hold up well. Lots of chipping. I found 16°-18° about ideal.

And have a look at a Feather AC Pro blade - the apex angle is pretty obtuse compared to most straight razors - 19° as measured by Todd Simpson with his FIB electron microscope. I doubt anyone here who has used one would say they don't cut well indeed.

 

[eKretz]

Here's a quick project I did tonight. I started with the "project-to-be" razor that I will use for a bunch of different tests/stones/techniques. This already had a decent edge on it but I wanted to start with a fresh clean slate. So I decided to put it on the DMT EEF (8K or 3μ) for a quick bevel set. Then I finished it on the same hone just to see what it looked like and to see what it would shave like. Then decided to strop it and see if there were any noticeable changes. There were, but only until about 200ish laps, then it seemed to stabilize, probably after the foil edge was all gone. So here is the series of images, (forgive the first one, I forgot to flip in the color filter).

You can recognize a few features that give a telltale that we are looking at the same exact portion of the edge. I am about to shave with it now and will report back afterward. I think it will probably be about like an 8k shave usually is...I can see by the focusing at the apex that it isn't as narrow as I'd like.

 

[eKretz]

Post shave shot:

So anyway, as expected, about par for the 8k course. There may have still been a little weak false edge there, it got worse as I went. You can see some new damage where either chipping or broken away false edge occurred. Made it through the WTG pass with no issues though. Didn't bother with an ATG, no point.

Not super fond of the amount of false edge there so I think I will try something else for the baseline.

I think I've mentioned to some of you guys before that I've done a LOT of testing and experimenting over the years. So this isn't the first time I've slurried an SG20k, by far... I even cut a couple rub stones from mine, must have been almost 10 years ago now. Here is a refresh using the SG20k with water, then a hone with some circles and then x-strokes on slurry generated with one of the rub stones. Both are pre-strop. I will go at it a little further later, but I'm beat for now.

 

[JPO]

Post shave shot:
View attachment 1311447

So anyway, as expected, about par for the 8k course. There may have still been a little weak false edge there, it got worse as I went. You can see some new damage where either chipping or broken away false edge occurred. Made it through the WTG pass with no issues though. Didn't bother with an ATG, no point.

Not super fond of the amount of false edge there so I think I will try something else for the baseline.

I think I've mentioned to some of you guys before that I've done a LOT of testing and experimenting over the years. So this isn't the first time I've slurried an SG20k, by far... I even cut a couple rub stones from mine, must have been almost 10 years ago now. Here is a refresh using the SG20k with water, then a hone with some circles and then x-strokes on slurry generated with one of the rub stones. Both are pre-strop. I will go at it a little further later, but I'm beat for now.

View attachment 1311455

View attachment 1311457

View attachment 1311456

This is really informative to me. It seems like the edge erodes from the fine synthetic slurry.
I have also tried the dmt EEF for bevel setting with similar results as you. I am wondering if you follow it with a so called conversion stone (8k), then a finisher, would that make a difference?
It would be a really simple setup to just to use the dmt EEF for bevel setting and follow it by two more stones.
How did you brake in the dmt EEF?
I guess the sub surface damage from the diamond is not possible to capture. I have seen some SEM photos where the sub surface damage from diamond is shown. The damage extends much further below the scratch then if a conventional water stone is used.

 

[eKretz]

This is really informative to me. It seems like the edge erodes from the fine synthetic slurry.
I have also tried the dmt EEF for bevel setting with similar results as you. I am wondering if you follow it with a so called conversion stone (8k), then a finisher, would that make a difference?
It would be a really simple setup to just to use the dmt EEF for bevel setting and follow it by two more stones.
How did you brake in the dmt EEF?
I guess the sub surface damage from the diamond is not possible to capture. I have seen some SEM photos where the sub surface damage from diamond is shown. The damage extends much further below the scratch then if a conventional water stone is used.

I'm going to try a few more courses of SG20k slurry on that razor and see if it goes backwards or forwards in refinement as I go. I have actually had pretty decent shaves from a slurry on that hone but not stellar. Having tried other synths with slurry I've found it to be detrimental to the edge in general. It gets worse with coarser grits in my experience.

My DMT EEF is very well worn in from probably a decade of use. As far as following it with a couple synths, that should be fine. The above image annotated "SG20k reset" was just basically taking the EEF edge to the SG20k until it cleaned up and straightened out. (Every one of the images is from the exact same section of the blade).

Subsurface damage I'm not sure about. As far as whether it could be viewed with an optical scope I mean. It's a lot of work anyway, the blade would need to be cross sectioned, so it's better to do on a sample piece instead of a razor. Probably a lot easier on the SEM. Anyway, that damage is actually not a lot below the scratch, for finer synthetic hones it's only like tenths of a micron IIRC.

I think a lot of the problem from using diamond plates is pretty evident in the stropping series - they are prone to create a wire edge/burr/false edge/whatever you want to call it. This is weak and ends up breaking away - depending on how much you've stropped, either immediately or after a ahort while, leaving you with a ragged edge and a harsh shave. That could probably be overcome with a lot (a lot) of stropping, but probably easier to just use a better finisher.

 

[eKretz]

Ok here is the rest of the SG20k slurry stuff. I did a couple more slurries, each with circles and x-strokes. Probably 10 minutes worth all told. Then took some pre-strop images, then stropped and took some more images. It does seem that the edge is degrading a bit with the slurry, but not terribly so. You can see that some false edge still broke away during stropping.

 

[Toro Blanco]

Those 1200 shots are some of the best I have ever seen! Great job ekretz!

Your light manipulation skills are on point!

Thanks for sharing.

 

[eKretz]

They are tricky, especially with all the controls and light-altering stuff, but all that stuff comes together to make for some nice images when it's set just right. 90% of those images is the scope, it's a pretty bad dude. I just cleaned it, haha.

I do need to get myself a nice fixture set up though. I can see that my reference points are wandering around just a little - I had been setting the razor in position by optical means (setting a certain point on the hollow part of the razor right in the middle of the photo crosshair at 50x, then increasing the magnification and moving down to the edge) but I bumped the stage once or twice with my hand and that little bit of vibration is enough to move things in the frame of the photo when magnified that much.

The "official" easy way to go about getting things square and flat to the lens is to put a little modelling clay or similar under the specimen and then use a device that presses down on top with a plate that is held rigidly planar to the surface it's pressing against. This gets everything in one plane. If I make a fixture that registers everything in the x and y axis, then use the press type device that should produce some very nice images. I will probably try some focus stacking too. So stay tuned, it will only get better...