Is 600x microscope sufficient?

[SHARPCO]

I want to see the tiny burr and LOW so I decided to order a digital microscope. 


https://ko.aliexpress.com/item/600X-digi...bdb71a419b

The above product is 600x and customer feedback is good. 

 Is 600x sufficient?

[grepper]

600X would be more than sufficient.   That scope may do an OK job of showing you small burrs and LOW.  

That said, I could be mistaken but I doubt that scope is 600X optical resolution.  At true 600X optical magnification the field of view would be very small, much less then 1 mm.

It's difficult to explain, but there is a difference between optical microscope magnification and magnification as displayed on a monitor.

What you want to look for, and what is rarely provided in digital microscope specs is "optical magnification.  Instead what is often given is something like 300X on a 16" monitor.  This way of looking at it means that if you have a 32" monitor the scope would be 600X because the 32" monitor is 2X larger than a 16" monitor. 

So, if you took the same image and displayed it on a highway billboard, you could say the magnification is 10,000X!

The important thing to understand is that the sensor of the scope is some number of pixels wide and tall.  That is the amount of data the optics of the scope provide.  The optics of the scope magnify the subject and focus that data onto the sensor.  That is optical magnification.  What the optics of the scope focus on the sensor.

You can blow that data up on a larger and larger display but the amount of actual image pixels remains the same.  Blow it up large enough and the image will start become grainy like looking at a newspaper under a magnifying glass.  You can see the print dots that make up the image.  Magnify it enough and all you will see is a bunch of dots.

Take any picture on your computer and start zooming into it with an image viewer.  Very quickly it becomes grainy because the image contains a limited amount of data.  If you have a 240x240 image you can't zoom in hardly at all, but if the image is 4,000x6000 there is enough image data to support more zooming.

Like I said, it is difficult to explain and will require you do considerable research to understand.  

My guess is that scope is maybe 150X - 200X optical, but 300X when displayed on the monitor.  But even that will more than likely show what you are looking for.

Another thing to consider is that 600X optical will have a very shallow depth of field, something like .2 um, so you will end up wanting to do focus stacking to show the whole burr and bevel.  Research depth of field (DOF) and optical microscopes.

Hope that helps.

[SHARPCO]

600X would be more than sufficient.   That scope may do an OK job of showing you small burrs and LOW.  

That said, I could be mistaken but I doubt that scope is 600X optical resolution.  At true 600X optical magnification the field of view would be very small, much less then 1 mm.

It's difficult to explain, but there is a difference between optical microscope magnification and magnification as displayed on a monitor.

What you want to look for, and what is rarely provided in digital microscope specs is "optical magnification.  Instead what is often given is something like 300X on a 16" monitor.  This way of looking at it means that if you have a 32" monitor the scope would be 600X because the 32" monitor is 2X larger than a 16" monitor. 

So, if you took the same image and displayed it on a highway billboard, you could say the magnification is 10,000X!

The important thing to understand is that the sensor of the scope is some number of pixels wide and tall.  That is the amount of data the optics of the scope provide.  The optics of the scope magnify the subject and focus that data onto the sensor.  That is optical magnification.  What the optics of the scope focus on the sensor.

You can blow that data up on a larger and larger display but the amount of actual image pixels remains the same.  Blow it up large enough and the image will start become grainy like looking at a newspaper under a magnifying glass.  You can see the print dots that make up the image.  Magnify it enough and all you will see is a bunch of dots.

Take any picture on your computer and start zooming into it with an image viewer.  Very quickly it becomes grainy because the image contains a limited amount of data.  If you have a 240x240 image you can't zoom in hardly at all, but if the image is 4,000x6000 there is enough image data to support more zooming.

Like I said, it is difficult to explain and will require you do considerable research to understand.  

My guess is that scope is maybe 150X - 200X optical, but 300X when displayed on the monitor.  But even that will more than likely show what you are looking for.

Another thing to consider is that 600X optical will have a very shallow depth of field, something like .2 um, so you will end up wanting to do focus stacking to show the whole burr and bevel.  Research depth of field (DOF) and optical microscopes.

Hope that helps.

You're right grepper. I'll find better one. 

The "real" microscope is very expensive, so I hope I will find a good product at a reasonable price.

[EOU]

Let us add our two-cents here SHARPCO. We calculate the magnification of our very inexpensive scope at 140X and that is more than sufficient to show LOW (LOW is EOUese for Line of Weld). LOW is a less than scientific term that we adopted as a means of describing the very difficult to remove portion of the burr formation. We termed it LOW because that's what it resembles - a tiny bead line of contiguous weld, very near the edge apex.

Grepper has put in the hours, research-wise, on scopes so you are both fortunate and smart to tap into that resource here. In addition, Grepper possesses  a practiced eye and feel for  things imaged based, much more so than our own. We can tell you this much - expenditure of a lot of money on a digital scope will not necessarily yield a good return on investment. We are aware of two digital scopes recently,$400.00 and $1,000+ respectively, that have gone back in the box  and been returned because they were judged to perform no better, or not as well, as  some $100.00 scopes. We don't bash individual products by brand name on the BESS Exchange but if someone has had a good experience with a particular brand and model of digital scope, no matter the price, please feel free to get specific and share.

[Ken S]

I recall reading that felt, or something similar, will fray with a rough edge. Would felt be a possible way to determine if any burr remained on an edge?

Ken

[Rupert Lucius]

I recall reading that felt, or something similar, will fray with a rough edge. Would felt be a possible way to determine if any burr remained on an edge?

Ken

May be a Q tip?

Rupert

[SHARPCO]

Let us add our two-cents here SHARPCO. We calculate the magnification of our very inexpensive scope at 140X and that is more than sufficient to show LOW (LOW is EOUese for Line of Weld). LOW is a less than scientific term that we adopted as a means of describing the very difficult to remove portion of the burr formation. We termed it LOW because that's what it resembles - a tiny bead line of contiguous weld, very near the edge apex.

Grepper has put in the hours, research-wise, on scopes so you are both fortunate and smart to tap into that resource here. In addition, Grepper possesses  a practiced eye and feel for  things imaged based, much more so than our own. We can tell you this much - expenditure of a lot of money on a digital scope will not necessarily yield a good return on investment. We are aware of two digital scopes recently,$400.00 and $1,000+ respectively, that have gone back in the box  and been returned because they were judged to perform no better, or not as well, as  some $100.00 scopes. We don't bash individual products by brand name on the BESS Exchange but if someone has had a good experience with a particular brand and model of digital scope, no matter the price, please feel free to get specific and share.

Thanks to you, I thought it was too early to exclude that digital microscope from the candidates. I don't know much about the microscope, so I need to find out more. 

I look forward to seeing LOW on the edge I sharpen. Of course, it would be better if I can see it

[EOU]

And thank you SHARPCO for your interesting posts. Don't know if you will see LOW in consideration of your individual grinding methodology. It certainly does appear on one side of the edge when grinding edge trailing and with relatively coarse belts i.e. 150-220 grit. You may find that other grinding techniques/grit progressions either don't produce the LOW in the first place or remove it at some point in the grinding process. 

One other consideration for you in the microscope selection process - the microscope stand. Almost any digital scope will expand your world and your knowledge base. The stand most less expensive scopes come with is a mess and greatly affects your ability to see and photograph, in-focus sections of the edge. Decent stands can be found for not much money. The one pictured below allows focusing by adjusting the stand elevation as opposed to twisting the focus ring on this very inexpensive scope.  That's huge because it seems that every time you touch the scope body, the area of interest shifts. A nice, solid and adjustable base is a big plus.

                                                                              

[SHARPCO]

And thank you SHARPCO for your interesting posts. Don't know if you will see LOW in consideration of your individual grinding methodology. It certainly does appear on one side of the edge when grinding edge trailing and with relatively coarse belts i.e. 150-220 grit. You may find that other grinding techniques/grit progressions either don't produce the LOW in the first place or remove it at some point in the grinding process. 

One other consideration for you in the microscope selection process - the microscope stand. Almost any digital scope will expand your world and your knowledge base. The stand most less expensive scopes come with is a mess and greatly affects your ability to see and photograph, in-focus sections of the edge. Decent stands can be found for not much money. The one pictured below allows focusing by adjusting the stand elevation as opposed to twisting the focus ring on this very inexpensive scope.  That's huge because it seems that every time you touch the scope body, the area of interest shifts. A nice, solid and adjustable base is a big plus.

                                                                          

Is it possible to grinding without producing LOW? That's interesting. My belt selection for knife sharpening is 60~120 -> 220 -> 400~600 -> 1000~1200 grit. Maybe LOW will be disappeared at some stage. 

And thank you for your explanation of the stand. Is the microscope in the picture good enough?

[Mark Reich]

OK... so, we need to make Grepper's post on 'scopes the beginning of a sticky topic if possible. Please. That's a Fabulous post my friend.

I have had a Veho 400 USB scope for years, but I gotta tell ya, it's seen virtually no use. I can see the LOW plainly and waaay quicker with my 80x toy microscope. If you make a pass and want to see exactly what happened on that pass, how long does it take to absolutely inspect the entire edge with a USB 'scope? What if you're inspecting every pass on a blade... like 10- 20 passes per side?

I may not understand, but is there an issue with the LOW? Do we know exactly what we're seeing?