Some ‘microscopy’ questions.

[Robin GrahamParticipant @robingraham42208]

I know next to nothing about microscopes or cameras etc, so I'm in that confused state of not even knowing what questions to ask, still less how to frame them.

So I'll start with what I would like to do and why, then go on to research so far.

On another (woodworking) forum I saw some pics of plane irons sharpened by different methods which he had taken with one of those cheap ($19 in his case) USB 'microscopes'. I thought I would like to do something similar as I sometimes make knives and my sharpening process is a bit hit-and-miss. I also wondered if having something like that might help with diagnosis of polishing problems – I do a lot of polishing.

I had a look on Amazon and there are many offerings. Most advertise 'magnifications' up to 1000x, which seems crazy to me for a device like this. On eBay there are claims of 1600x, which seems even madder. Amazon reviews are patchy – some, who seem to know what they're talking about, say that these things are no better than a 10x loupe.

I looked at an offering from AmScope which claims 10x – 200x and even gives the sensor size – 0.3Mpx – so they're perhaps being more realistic and honest. Only £35, so maybe worth a punt.

Further research makes me wonder if these things are more akin to macro cameras than microscopes, but I don't really know what I'm talking about.

I'd be OK going up to maybe £200 for a trad microscope, and worry about getting an eyepiece camera later. Would that be better for what I want to do? Can it be done on that sort of budget?

Apologies for nebulous nature of this question, but I have to start somewhere!

Robin.

 

Edited By Robin Graham on 13/09/2022 23:05:06

[Robin GrahamParticipant @robingraham42208]

[Michael GilliganParticipant @michaelgilligan61133]

High magnifications quoted like that are generally inclusive of the assumed screen size … so the sky’s the limit.

It sounds highly dubious, but even Leica has done it.

The best I can suggest tonight, Robin, is that you trawl the net for honest examples of the pictures that these things produce. There are many variables, and it would take forever to make your selection from first principles … just find something that demonstrably produces the sort of pictures you want, of the sort of things you are interested in.

More tomorrow if I think of anything useful

MichaelG.

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Found that Leica page quicker than I thought I would:

https://www.leica-microsystems.com/science-lab/what-does-300001-magnification-really-mean/

Read, inwardly digest, and probably buy something much cheaper !!

Edited By Michael Gilligan on 13/09/2022 23:20:56

[Michael GilliganParticipant @michaelgilligan61133]

Dino-Lite is at the upper end of the ‘USB microscope’ category … and deservedly so

and Pepler Optics is a good firm to deal with

So you might start here for your ‘window shopping’ **LINK**

https://www.pepleroptics.com/digital-microscopes/universal-usb

You can work your way down from there 

MichaelG.

Edited By Michael Gilligan on 13/09/2022 23:34:12

[Max ToleranceParticipant @maxtolerance69251]

Be very careful about claimed magnification in any optical device. The real test of an instrument is its resolution. The ability to show details and resolve minute differences in size, shape, colour etc. There is in microscope circles something called empty magnification where the view may be bigger but no more detail is revealed. There is a definite limit to the resolving power of even the finest optical microscopes. This is one of the reasons why different techniques such as dark field,oil immersion, polarization etc. are used.

However, for the purpose you intend it for you would not need such high magnification. And in all probability a cheap electronic device may well serve your needs. As always with these devices the sensor, and the screen will decide the quality of the image. A large magnification with a very poor screen will not show anything worth having. A lower magnification but with a high definition screen will reveal much more.

As the previous poster says, look at real world images taken with the camera, microscope , whatever and decide if the quality is sufficient from that.

[Robin GrahamParticipant @robingraham42208]

Posted by Michael Gilligan on 13/09/2022 23:18:03:

High magnifications quoted like that are generally inclusive of the assumed screen size … so the sky’s the limit.

It sounds highly dubious, but even Leica has done it.

The best I can suggest tonight, Robin, is that you trawl the net for honest examples of the pictures that these things produce. There are many variables, and it would take forever to make your selection from first principles … just find something that demonstrably produces the sort of pictures you want, of the sort of things you are interested in.

More tomorrow if I think of anything useful

MichaelG.

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Found that Leica page quicker than I thought I would:

**LINK**

Read, inwardly digest, and probably buy something much cheaper !!

Edited By Michael Gilligan on 13/09/2022 23:20:56

Thanks Michael – not yet read, but encouraged by the title of the article because when trying to think about it all I realised that I didn't know what magnification meant and began to think that resolution was a much more useful concept. So I might be on the right track!

Robin.

[PeroParticipant @pero]

Hi Robin

A few comments on the basics.

For your work you will be needing illumination from above not below as would be used in the typical light microscope ( i.e. of the type using glass slides ). For this purpose either a basic binocular dissecting microscope or a usb type digital microscope would suffice. If you want to take photographs the the digital type would be preferable. Trinocular dissecting microscopes, which use a third tube for a camera, are available but are expensive, even if ex China.

The other issue to consider is what is the field of view required. If you are wanting to look at knife or tool edges then you will want a reasonably wide field of view. Similarly for polishing unless you want to get down to very fine ( i.e. micron ) levels of investigation. Again, the dissecting or one of the usb digitals would be preferable for this purpose.

My personal preference would be for a binocular dissecting microscope over the digital but perhaps that just reflects the type of equipment I was trained on. Admittedly all of my current microscopes have high definition digital cameras fitted so I can have the best of both worlds.

I haven't checked the UK situation but I expect that most tertiary institutions are now disposing of older equipment so some bargains may be available. Just check to see that they haven't been dropped too often! A camera adapter tube can be used with one of these to minimise additional cost.

Hope this helps

Pero

[not done it yetParticipant @notdoneityet]

These claims of high magnifications are rife amongst the cheap items – just the usual marketing hype to befuddle the unknowing. What it actually means, for the claimed x1000, is x30 (the square root of 1000)

0ne needs a reasonably good laboratory microscope for x400 (‘A’ level biology?), and the electronic ones can range from good to rubbish. Any more and proper laboratory microscopes would be into oil immersion lenses, I would think (they were when I was at school, but no doubt have progressed ince then 🙂 ).

My wife regularly uses a £10 magnifier on her mobile phone to enhance the view of fine lace. Very small lenses can give a x20 pic with a tiny field of view. It just depends on what you actually want and need. Any knife edge may well look like a damaged woodworking saw blade, if magnified enough, but still function very well.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 14/09/2022 05:54:14:

These claims of high magnifications are rife amongst the cheap items – just the usual marketing hype to befuddle the unknowing. […]

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True as that might be … You might like to know that there is a published Standard available

This is referenced at [10] in the Leica document that I linked.

[ of course the rogues and scoundrels might just ignore it ]

MichaelG.

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The unknowing might be befuddled by marketing hype

… The knowing stand a better chance.

Edited By Michael Gilligan on 14/09/2022 08:52:18

[jaCK HobsonParticipant @jackhobson50760]

I have often used stuff to inspect blade edges. You don't need to spend much to see a lot.

search amazon for 'pocket microscope'. Less than £20. Something like https://www.inglesport.com/product/carson-microbrite-plus-60x-120x-pocket-microscope/. (more handy as you don't need a computer, and I don't have a computer where I tend to do my sharpening)

Macro on a good mobile phone and zoom in.

10x loupe.

Cheapest USB microscope. I think you will be limited by contrast/colour depth rather than magnification with the cheap ones.

The magnification they quote must depend on the screen size viewing Or area as suggested above.

The actual optics are nothing like x1600 in proper microscope terms. You probably need to replace the air between the lens and subject with oil at that power…

Conclusion : Anything will help with your sharpening. You certainly don't need to spend much.

 

Edited By jaCK Hobson on 14/09/2022 09:43:34

[HOWARDTParticipant @howardt]

High magnifications are not optical, they are created by software rendering of the pixels captured by the sensor. You only have to compare older digital cameras to modern ones to see how software has moved on. My son has worked with creating imaging software for microscopy for quite a few years and is amazing how it has moved on.

[Raymond GriffinParticipant @raymondgriffin40985]

Hi Robin,

I attach some photos that I took this morning. I was using a cheap USB digital microscope from Celestron. The magnification range is 10X to 150X and the photos are of lowly resolution. I attach it to my computer and use the basic windows camera app. The microscope came with software that was more sophisticated and I believe that there is good software on the internet. The windows version is good for my purposes.

The pictures are low and higher power images. One is a new Swan Morton scalpel blade and the other the cutting edge of a microtome knife used to cut thin slices of tissue embedded in paraffin wax for microscopy. It is clear that the polishing of the cutting facet of the microtome knife is superior to the scalpel blade. I do not know if you require this level of “sharpness”.

In general terms the Celestron suites my purposes in the workshop. I would be wary of cheap devices offering enormous magnifications. High magnifications and good resolution cost a lot of money. I do have “proper” microscopes and use them often, but when it comes to a quick look at the finish on something from my lathe or milling machine the Celestron comes out. It is sufficient, quick to set up and use. With all microscopy, and photography, lighting is the key to good images and needs to be done properly. If I do have a gripe with the Celestron it is the ring of LSD’s around the lens. OK for most purposes but need supplementary side lighting on shiny metal.

Now and again, I think about replacing it with something giving higher resolution, but it needs a lot of research.

Ray Griffin

[Michael GilliganParticipant @michaelgilligan61133]

It’s good to see blades being a favoured subject for microscopy.

One of Robert Hooke’s famous illustrations in Micrographia was the edge of his razor

The man’s observation and drawing skills continue to astonish me !!

MichaelG.

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**LINK**

Microscopic views of the point of a needle; printed full-stop; edge of razor

[Iain DownsParticipant @iaindowns78295]

I have a cheap USB microscope which has variable magnification, but it's built to a price. It's hard to change the zoom and focus without seriously moving the image.

I've also got a trinocular microscope from AliExpress which cost a little over £200 (£220 if I have it right).

For reference it's here but there are many more there with similar

I got this for use with watches and I have been happy with it so far. I picked a *.5 bowler lens which increased the objective distance from 4 inches to 8 inches to allow me to get my hands and tools into the watch. It also reduce the top magnification from 100 to 50. YOu can go the other way and put A 2X bowler on taking it up to 200x peak magnification.

Being cheap, I built my own sliding stand (all of the metal was in my stock box or it would most likely cost more than buying from china).

I also bought a cheap web cam, removed the case, added a new one and an appropriate reduction lens (0.3 in this case) and got the camera port working for MUCH less than the price of a camera from China.

I am very pleased with the whole set up ( and someday soon may start to use it in anger!). Perhaps the image quality of the camera would be better of the field of view wider with a special camera, but it works well enough.

One thing – microscopes and especially cameras are complicated things. It is very easy to buy bits that don't really work together. You Tube a lot.

Iain

[Robin GrahamParticipant @robingraham42208]

Thanks for replies, which have all been helpful. I'm now thinking that I should probably just get a cheap USB device as a way of dipping my toe into what is evidently deep water.

Raymond – thanks for the pics. Can you tell me which model of Celestron camera you used? They seem to have quite a range.

Michael – thanks for the link to the Micrographia illustrations. I have ordered a pack of greeting cards – if the recipients don't like them, well that's their problem.

Robin.

[Alan CharlestonParticipant @alancharleston78882]

Hi Robin,

I've got over a dozen microscopes of various types including ones with incident illumination (from above) and a few dissecting microscopes. It I want to check the sharpness of ground lathe tools however, I use a cheap plastic jewellers loupe (the kind you screw into your eye). It provides enough magnification to see whether there is a flat on the cutting edge and is cheap enough to try before splashing out on something more expensive. It also has the advantage of pretty much zero setup time – out of your pocket and into your eye in only a few seconds.

Regards,

Alan C.

[not done it yetParticipant @notdoneityet]

I have two higher magnification microscopes. A USB thingy that my wife prefers and a proper optical microscope which is typically used for most biological cells that I might want to inspect. Main use would likely be at, or close to, x400 to check for nosema spores from bee extracts and occasionally pollen in honey. My small pocket microscope is about x30, I would guess – useful for finding tiny metal slivers, on occasions.

[Raymond GriffinParticipant @raymondgriffin40985]

Hi Robin, I use a Celestron 44302. It was purchase from Amazon. UK for £47 in 2012. Do not know if this model remains available. Perhaps they will have improved. Mine came with a little stand that was useless for my purposes. I made up a flexible arm from my odds box. See photo.

Hi Michael, as you say, the patience and skill of some people is astounding. I have a biography of Robert Hooke by Lisa Jardine. It is a very good read. Also, I went to the Museo Camillo Golgi at Pavia just before Covid struck us. Not everyone’s cup of tea, but to those of us studying the ultrastructure of cells and tissues a maestro. The curator invited me to use his drawing microscope, photo attached. Used to make the drawings of neurones and nerves that resulted in his Nobel prize. He must have had enormous patience and skill. It must have taken hours to make each drawing. I found it very difficult to produce anything resembling what I saw, although I have taken hundreds of photos using microscopes.

Ray G

 

As usual with this site my photos have been rotated. Apologies.

mod edit: photos fixed

Edited By SillyOldDuffer on 15/09/2022 22:10:38

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Raymond Griffin on 15/09/2022 17:03:02:

I went to the Museo Camillo Golgi at Pavia just before Covid struck us. Not everyone’s cup of tea, but to those of us studying the ultrastructure of cells and tissues a maestro. The curator invited me to use his drawing microscope, photo attached […]

As usual with this site my photos have been rotated. Apologies.

.

Thanks for that, Raymond

Only a Moderator can rotate your photo now … but I will grab it and rotate my copy, to save standing on my head

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

I took the liberty of cropping Raymond’s photo, and lifting the shadows a bit.

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Very envious of you getting to try that, Raymond !

MichaelG.

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Ref. __ http://museocamillogolgi.unipv.eu/homepageeng/

Edited By Michael Gilligan on 15/09/2022 19:07:28

[Robert Atkinson 2Participant @robertatkinson2]

The £35 Amscope USB device you linked to in your first post will almost certainly do what you want . It is basically a webcam with a magnifying lens. It has a built in ring light so good for looking at opaque objects.

I have a optically similar one but it has a small built in screen and SD card for recording images. No need to be connected to a PC.

Robert G8RPI

Edited By Robert Atkinson 2 on 15/09/2022 20:44:20

[Robin GrahamParticipant @robingraham42208]

Thanks for further replies.

Raymond – thanks for further info about your Celestron. That model (suffixed with -C) is still available, albeit at ~£70, which is probably reasonable compared to the £47 you paid in 2012 given that the cost of tools imported from the Far East seems to be rising more rapidly than the general rate of inflation.

Robert G8RPI – thanks for your comment re the Amscope offering.

A couple more questions though. First is that the Celestron has a 2 megapixel camera, the Amscope 0.3 megapixels. What difference would that make, assuming (hypothetically) that the optics are the same?

Second is that the Amscope description says explicitly that device adheres to the UVC standard, so should be usable with my Linux machines, but the Celestron says that only Windows and Mac OS operating systems are supported. It may be that Celestron are referring only to ancillary image processing software supplied with the device – I don't need that, provided I can capture an image in a format the GIMP recognises. Is it just that everything is UVC these days, so no need to mention it?

The third (in my 'baker's couple'  of questions is about ndiy's explanation of the quoted magnification being the square of the 'actual' magnification. Is that just because they are talking about area magnification rather than linear, or is there some more subtle optical thing going on?

Thanks for your patience in answering my naive questions,

Robin.

Edited to get rid of an unintended 'wink'.

 

Edited By Robin Graham on 15/09/2022 23:39:57

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Robin Graham on 15/09/2022 23:37:36:

A couple more questions though. First is that the Celestron has a 2 megapixel camera, the Amscope 0.3 megapixels. What difference would that make, assuming (hypothetically) that the optics are the same?

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My ‘rule of thumb’

0.3 megapixels might be just sufficient for ‘live’ inspection, but saved images are likely to disappoint.

2 megapixels is sufficient to put a useable image on a monitor or TV

5 megapixels would allow you to usefully zoom-in on the image.

BIG caveat … I am talking about genuine ‘native resolution of the sensor’ here, not the ridiculous numbers that are sometimes advertised for interpolated images.

MichaelG.

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Please, Robin … take some time to have a look at the reviews by Pepler Optics [mentioned earlier] of the range of such products that they sell :

https://www.pepleroptics.com/infozone/usb-microscope-review/

This is a respected dealer, doing what a dealer should.

Edited By Michael Gilligan on 16/09/2022 06:27:11

[Michael GilliganParticipant @michaelgilligan61133]

Postscript:

There is a useful video included in the Pepler review of the Basic Dino-Lite:

**LINK**

https://www.pepleroptics.com/dino-lite-am2111-usb-microscope-640-x-480-pixels-10-60x

For a 640×480 sensor it’s impressive.

MichaelG.

[ no, I’m not on commission ]

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, this may be of interest. I have two cheap USB digital microscopes, one which was cheaper than the other, but the better one is a Maplin Gadget one. It does take decent photos, but results are varied depending on how the light from the LED's is reflected of the item being viewed. The software includes measurements to be made, but they don't guarantee accuracy and the magnification ratio scale isn't truly correct, so I first took a photo of a "Precision Edge" X-ACTO square with inch measurements, divided into 1/32" and calculated the magnification ratio from that.

The next photo is a section of a Swan Morton No. 21 blade at about 20 x.

This one is looking at the actual edge with the point of the blade at the left, again at about 20 x, and you will notice how shallow the depth of field is, as only approximately 2mm at the tip is in focus.

The last Photo is a very close up portion part of the ground part which forms the edge, which is at the bottom of the photo, this was at the maximum of 400 x. which it claimed that the microscope could do, but was very difficult to achieve a decent result, with the edge just slightly out of focus. You may notice some grey and black small dots in various places, which are not actually on the blade, these are probably tiny specks of dirt on one of the lenses inside the microscope, which have developed over time, as I've had it a good number of years.

It's not a tool to do serious research with, but it is useful for a looking at things very close up, but because of its age, it won't work on any Windows system after Vista. Maybe I might try one of those lower priced ones that MichaelG linked to in his post above. The other one that I have is in some situations better, but the LEDs can't be dimmed, and so shine too much light at times, and that will also only work up too Vista system.

Regards Nick.

Edited By Nicholas Farr on 17/09/2022 11:30:26

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