Using the Loupe

[Jakebullet]

I’ve been using straights a couple of years now, I Hone my own razors. I have a loupe about 30x magnification I think. My question is what exactly are you looking for when you’re assessing your work with the loupe?
For example, I’ve heard it said The loupe can be used to observe the scratch pattern on the bevel but try as I might
the bevel always looks pretty mirror to me save for the odd deeper scratch. Also is it just me who finds it difficult as hell to line up the bevel and loupe with a source of light that doesn’t blind me or I sn’t obscured by my own shadow?
I’ve heard it said to check with the loupe to make sure the scratches go all the way to the edge but again it’s just mostly mirror to me.
I’ve read that if you look edge on from above the razor that areas in need of work will appear as bright spots but I can’t see such a fine thing as that edge head on and the closer I get peering over the invisible edge the more my heart rate increases.
So what do you look for when using the loupe? What clues are you using to assess your progress?

 

[Gamma]

A 100 people will have 400 different answers to this.
For me, it depends. I feel first, look second.
One thing that is constant, is looking for 'what doesn't belong'. Like that kids game.
For starters, tiny distractions like burrs that reflect light differently than the rest of the bevel/apex.
Other stuff - alignment of striations, consistency in striations. Even-ness of 'polish' - or continuity in reflectivity from toe-to-heel.
I might feel 'something' near the toe - so I might focus on that area to see if there is an anomaly; pitting, micro-pitting, weird stria termination, failure at the apex, and so on.
Some will say they look to see if all the striations from the last stone are gone. I don't believe that is a solid indication to move forward 100% of the time. Edge development is not as linear as some would think it is or would like it to be.
I look, I feel, I listen, then I feel some more. When the feedback from all senses line up, then I go forward.

 

[KW Driver]

I can't disagree with any point Gamma made. I didn't like using cheap hand loupes for generally the same reasons mentioned plus wearing glasses (or not) was an additional complication. I picked up a $40 USB lit microscope that I can use to look at the image on a computer screen. it's just easier. and I tend to use it to verify my work, and generally use it to look at the apex of the edges. it's a lot easier to use than a hand loupe.

 

[Tomo]

I mainly just examine the edge for any chips and check the evenness of the polish and any missed sections. You can monitor how scratches are being removed during a progress at higher grits. I have seen a trick where people hone one stone with the blade at an angle and the next one with the blade perpendicular. This lets you see which scratches are from which stone.

I have three loupes. A Zeiss D40 10x, Belomo 20x and a cheap eBay claiming to be 30x. The Zeiss is the best all arounder. 10x is easy to focus and easy to catch the light. The 20x is a PITA. You need to be so close to the object that you block all the light. The focus point is so sensitive that you always loose focus. The cheap eBay is ok but the image is warped at the edges. There’s no way it’s 30x probably 10x.

10x is the standard jewlers loupe for examining gems and diamonds. Anything higher than this is difficult to use hand held. After 10-12x you are better off using a microscope IMO.

I sometimes have an issue with fogging the lense if the loupe is cold. If you warm the loupe you in your pocket it doesn’t fog up.

 

[stone and strop]

I’ve been using straights a couple of years now, I Hone my own razors. I have a loupe about 30x magnification I think. My question is what exactly are you looking for when you’re assessing your work with the loupe?
For example, I’ve heard it said The loupe can be used to observe the scratch pattern on the bevel but try as I might
the bevel always looks pretty mirror to me save for the odd deeper scratch. Also is it just me who finds it difficult as hell to line up the bevel and loupe with a source of light that doesn’t blind me or I sn’t obscured by my own shadow?
I’ve heard it said to check with the loupe to make sure the scratches go all the way to the edge but again it’s just mostly mirror to me.
I’ve read that if you look edge on from above the razor that areas in need of work will appear as bright spots but I can’t see such a fine thing as that edge head on and the closer I get peering over the invisible edge the more my heart rate increases.
So what do you look for when using the loupe? What clues are you using to assess your progress?

If all you can see is a mirror finish then I would suggest you turn the loupe so the light is coming from a different direction.
Quality of loupe is important. Given the angle of approach, with my loupe, I can easily see the change in striations, the mirror polish and very small chips and irregularities.
I can see them so well that if I can't see it with the loupe it is not an issue.
I have used a microscope for years now but still employ a loupe when not at the station.

 

[rbscebu]

Once you start getting down to about 50k grit or finer, you will not be able to see the striations optically, either with loupé or microscope. This is due to the wavelength of light being about 0.3um. To then see the striations, you will need to use a SEM.

 

[Tomo]

Once you start getting down to about 50k grit or finer, you will not be able to see the striations optically, either with loupé or microscope. This is due to the wavelength of light being about 0.3um. To then see the striations, you will need to use a SEM.

All I see after 0.1u paste is a mirror polish on the bevel under 10x magnification. At higher film grits you can monitor your progress. I also find the loupe useful for checking that the bevel is fully developed. The loupe will clearly show if there are any Sharpie marks remaining near the apex.

 

[Slash McCoy]

I like my 10x Belomo Triplet. A good balance between power and ease of use. No, you can't really see a fine scratch pattern but I look at reflections more than scratch patterns. For scratch patterns, a 100x or stronger USB microscope is great, but it can be very fidgety. I have a regular lab type optical microscome with a USB eyepiece, and I can go up to 2k with it but it is extremely hard to get a usable pic with it. I have posted a few on the forum in the past. Mostly it is just gathering dust these days. I hone with my loupe or my 4k magnifying glass. The light source is just as important as the optics, BTW. I will look on my website and see if I have a pic or two to post here, as example.

Okay, the first two bevel setting pics are pics of the same edge, just different lighting angle. As you can see, the bevel is not there at all yet. The third one is a little closer to a bevel, but I have zeroed in on a spot where it still isn't there all the way. The fourth and final pic is looking out from teel toward the toe, and you can clearly see a well developed burr.

Guess how I took those pics. HAH. I used one of my old Note 3 phones, no other optics, just zoomed in hard and held close, using my finger on the screen to make the autofocus zero in on a desired area. The light is more important than the optics. Now like Gamma said, feel is important, too, and in this last pic, the burr is very easy to feel. This is an extreme burr raised specifically for the purpose of the pic. Notice my finger and my fingerprint ridges clearly visible even though they are out of focus in the foreground. You can see the pivot pin of the razor, a Gold Dollar P81. In the first pic you can clearly see 600 grit scratches, and also in #3.

Rolling the razor just a degree or two completely changes the view, revealing or obscuring honed facets or raw grind facets. You are looking for differences, and you are looking for when they appear and disappear in relation to one another. What looks out of place probably doesn't belong. In the incomplete bevel pics, as you develop the bevel, the honed facet grows wider and the unhoned part narrower. The edge trash shows with the light just right. In fact, the first two pics are of particular interest. Not only is the bevel incomplete on the viewed side, but you can also see a burr from honing the other side and deliberately raising the burr as part of setting the bevel. Continuing to hone the viewed side will eventually cause the bevel to totally swallow up the uncontacted area right at the edge, and push that burr over to the other side, at which point both sides have had a burr, each in its turn, and simply honing away the burr leaves a proven bevel.

Now these pics were taken with an old celphone. Almost antique, in cell phone years. Imagine what you can do with a 100x USB scope and a bright light. But you got to turn it in the light, and watch the reflections move around and change. Where is it bright? Where is it dull? When you roll it a little THIS way, what happens? Imagine that your razor is 5 feet long. What will you see, when there is a ding or chip and it is almost gone? What will you see when a raw razor with a factory edge has been given 50 circle strokes on a 320? 1k? Even on out through the progression, when you can't see the scratch pattern, you can still see changes in brilliance. Look at the whole picture, not just the scratches. Manipulate the razor and camera to make different angles of incidence.

So you see why a 10x loupe is such a powerful tool, even though you can get one up to 30x, or a microscope up to the actual limits of useful optical magnification. It's not just the lens. The light and the hand and the mind that tells the hand what to do, are every bit as important.

Bottom line is just play around with it and observe. It will all come to you.

 

[Tomo]

I used one of my old Note 3 phones, no other optics, just zoomed in hard and held close, using my finger on the screen to make the autofocus zero in on a desired area.

Don’t laugh but I actually use this set up a quote a bit to take zoomed in photos. It actually works really well when you lock the autofocus. The iPhone camera has very good optics. 10x optical plus 10x digital zoom takes a pretty good photo if you hold the camera still and have good light. Putting the ‘devise’ on a book or similar ‘tripod’ works well.

 

[Slash McCoy]

Nothing to laugh at. They make all sorts of clamp-on microscopes for phone cams and they work pretty good. Yours is just the economy version.

 

[stone and strop]

I have no problem seeing scratches on a .5 um. edge with my loupe.

 

[Njguy1977]

Don’t laugh but I actually use this set up a quote a bit to take zoomed in photos. It actually works really well when you lock the autofocus. The iPhone camera has very good optics. 10x optical plus 10x digital zoom takes a pretty good photo if you hold the camera still and have good light. Putting the ‘devise’ on a book or similar ‘tripod’ works well. View attachment 1172898

Greatest idea EVER! I am blind in one eye and my non dominate eye is the one that works and makes things so difficult to look through a loupe. This idea takes the use of 1 eye out if the equation for me. BRAVO sir, BRAVO

Larry

 

[Steve56]

Bevel is set on the left (green circle), not set on the right (blue circle). Also taken with a loupe rubber banded to an iPhone.

 

[kohalajohn]

Wow, that image is actually better than what I get on my fifty dollar usb microscope

 

[Eastcoast30]

I find the 30x hard to work with - you need to get very close and that makes it hard to get light in there. I find the Belomo 10x to be perfect.

 

[Frank Shaves]

I recently switched to using a Belomo 10x Triplet based on @Slash McCoy's recommendation. Over the weekend I experimented with different light sources and found natural light to be the best followed by old-school long fluorescent tubes. My LEDs are OK, as well as incandescent. Compact fluorescent is the pits.

I like the loupe on phone with rubber band - that is cool!