Barmaley's Aggregated Questions Thread

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Barmaley

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Dec 31, 2016
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Hello,

I am new at knives sharpening and would like to see my results with my own eyes! What should I know about loupe selections. What is the right magnification? 20x? 100X? Can someone recommend a brand and model? Is it important to get a good one or I should focus on sharpening stone selection and grab the first one on Amazon?
 
For sharpening I use a 5x watch makers loupe. I also have a loupe used for photographic film negatives that feels like about 10x.
Anything more I think is overkill.
If you are going to use it for gems, then you need at least 10-20x or more.
I believe my loupes are Bausch and Lomb.
 
For many years I have gotten great performance from the "15-Power Lighted Loupe" from Lee Valley. It has just the right amount of magnification for my needs (too little isn't helpful and too much gets me "lost in the weeds"), and it's very clear. The lighting feature is great and it uses 3xAAA batteries instead of the annoying and harder to find little button cells. It's solidly built, has never given me a single problem, and I rely on it daily.

Andrew
 
I've tried handheld magnifiers (mostly good quality, with illumination) from about 10X to 120X and none worked well for me. Either they were not powerful enough or the magnified area was too small and too hard to focus and keep focused. But not everybody is looking for the same things regarding knife edges. Maybe I want more detail than most. Obviously many people like and use loupes and other types of magnifiers.

If I decide to go further with this I'll probably get a USB microscope.
 
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I have several loupes, but the one that works the best is an illuminated 10X by Grobet USA. It's a triplet 10X-21 mm. That 21 mm size of the lens is just about right.

I have a Zeiss 10X-12 mm with better glass, but the 12 mm lens is a little too small.
 
10x is a good power. The higher ones make viewing more difficult.

Lighted ones are preferred by some, but I always have lights on and I found that I did not like the one with a light in my preference.

The one that I use is a BelOmo triplet 10x. It is a good value and the lens is very clear. It is a very good loupe.

A lot of folks really like the USB microscopes to check edges. I have not used one, the photos look great!!
 
bucketstove said:
Hi, Please elaborate.
Click to expand...

IIRC I bought a couple of under-ten-dollar loupes from eBay or Amazon and the ranking of the rated powers did not match the perceived magnification. I sought an explanation and found that this is a common complaint. Perhaps someone has a (cheap) "15X" and gets a (cheap) "30X" and finds it is exactly the same, or they compare their cheap "20X" to someone's better 10X loupe and find that it magnifies less. I have since then bought a few more and given most away and the rated powers seemed pretty capricious. I became uncomfortable holding a knife that close to my face when I was tired so I usually use a USB magnifier now when I really need to see something.
 
thank you guys for sharing your experience. This morning I pulled all magnifying glass I have (about half a dozen) and tried them all. I was nor happy with the results. I looked on ebay for 30x loupe with LED light and they look too suspicious. I doubt that one glass can make 30x magnification. Internet search consistently sends me to theory of optics, not very practical option. Can somebody clear up the confusion with multiplication numbers. Intuitively I think I need about 10-15 times larger picture to see burr and the edge clear, however I think I need at least two glass system to get such result - am I wrong? Does multiplication related to focus of a glass? Can I improve old photo camera lens to make it a microscope?

At the mean time I already found a lot about why my knives are dull. Under a loupe I found that I did not cut enough of the edge to get to apex. I am sure good magnification can substantially help!
 
Barmaley said:
Can I improve old photo camera lens to make it a microscope?
Click to expand...

You surely can use a manual camera lens of an appropriate focal length as a magnifier. You look through it backward, and as I recall the shorter the focal length (the wider the field of view when used normally) the greater the magnification when used this way. Or perhaps you know this and want to improve it somehow, but in what way?
 
Hello everybody,

I am shopping for DMT double sided 300-400 one side and 1000-1200 other side (based on an advice from YouTube as an only stone to use). However, I got two conflicting opinions on the life span. Some people suggest that it will last lifetime, others say that they will wear out. I am planning to use them to sharpen my kitchen knives and I am not using anything harder than VG10. How many knived can I sharpen on a stone before diamonds will fall off? Will ceramic stone from Spyderco last longer? My pragmatic goal is to spend as little as possible in order to get life long quality solution. I am looking for very sharp knives for cooking but I don't have to shave with them - I have an electric shaver.
 
Mr.Wizard said:
Or perhaps you know this and want to improve it somehow, but in what way?
Click to expand...
I used Yashika 70-210 photo camera lens and it was great help to see the edge of the knife I was working on. However, I would like to get about 5 times higher magnification. Can I pry the lens and make changes (add another glass, move glasses farther apart etc) to see larger picture?
 
We seem to have changed topics now? If you are seeking magnification in that range with good optical quality (actual resolving power) I think you need a research grade optical microscope. However even the best optical microscope cannot reveal the finest details of an edge the way an electron microscope can, therefore it could still be misleading. Example below.

ToddS said:
Shapton Glass 16k on a S30V knife (edge leading strokes):

Same area imaged by optical microscope and SEM....


s30vsh16k.jpg
s30v_sh16k_03.jpg
s30v_sh16k_08.jpg
Click to expand...
 
The Spyderco ceramic should outlive us all if it is not dropped or misused.

Joe Calton of Calton Cutlery says this regarding the DMT 325:

Joe Calton said:
I think for the majority of folks one of these would probably last you a decade or more unless you were a butcher or a tradesman or somebody that you were sharpening your knife on a daily or weekly basis. For me I go through a couple of these a year but I sharpen a ton of knives.
Click to expand...

 
A ceramic stone will last several lifetimes but it's not coarse enough to reprofile a blade. Neither is a 300 grit diamond. Something like a Norton
IB8 is. Then finish it off on a 400 grit India stone. This will give you a nice kitchen working edge. Taking it real fine is not needed unless you just
prefer it that way. DM
 
I used the same DMT 6" bench hones for more than two decades --they worked just as well as when new -- and then gave them to my BIL when I got the 8" double-sided one. I clean them with BreakFree CLP when they get loaded with swarf.
 
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