Digital microscope - Page 1
Forum section: electronics / general

author: bob91343
author_rank: Super Contributor
timestamp: July 21, 2020, 09:21:24 pm
content: I see some little items from China for interface to PC or phone via USB. They are around $20 or less. Specs include x1000 or x1600 but only 640x480 video.How appropriate are these for PC board repair work? Has anyone used one with success?For instance I have a nanoVNA with the USB C connector removed and I want to reinstall it, but the pin pitch is so small I can't resolve it with the naked eye.

author: phil from seattle
author_rank: Super Contributor
timestamp: July 21, 2020, 09:59:04 pm
content: I've tried a number of those cheap microscopes. Inevitably, they are a total waste of money. The only one that doesn't completely suck is this one pictured below. iirc, it was $70 USD. However, I did not see it when I looked on ebay and amazon. I think any $20 device will be pretty much terrible. FWIW, I use a magnifying lens for most assembly work and occasionally a second hand Olympus stereo microscope. The strero scope was about $275 USD.edit: by the way, worst part is these all have significant lag making it almost impossible to use to position things.I am playing with the new RasPi HQ camera on a PI4 and it has a sub 1 second lag. The image is excellant. Very usable. Will run you over $100 all in.

author: bob91343
author_rank: Super Contributor
timestamp: July 21, 2020, 10:34:44 pm
content: I'm not sure if the use of this thing is worth $70, but I'd be interested in delving into it. Do you have a link?I have an endoscope I bought a year or two ago and it doesn't have enough magnification. I also have an optical microscope but it's not mechanically adaptable to circuit board work. It's a traditional style with a stage and rack and pinion focusing.

author: cliffyk
author_rank: Frequent Contributor
timestamp: July 21, 2020, 11:35:26 pm
content: i havethis fella', $52.90 from Amazonand have been very pleased with it:Made some mods, a 3D printed crank handle for elevation and a 12° offset mounting bracket wedge to bounce reflections from the "LED ring lights" off in another direction:

author: phil from seattle
author_rank: Super Contributor
timestamp: July 22, 2020, 12:00:14 am
content: Quote from: bob91343 on July 21, 2020, 10:34:44 pmNo, I don't have a link unfortunately. And didn't see it listed either. sorry.

author: bob91343
author_rank: Super Contributor
timestamp: July 22, 2020, 02:36:44 am
content: Thanks for the pics. I looked up that unit and, as expected, it was considerably cheaper on ebay. I didn't see enough info to see how it mounts or the power source or the screen resolution so I sent an inquiry to the seller. But it might be what I'm looking for.

author: niconiconi
author_rank: Frequent Contributor
timestamp: July 23, 2020, 03:59:54 pm
content: I have one. I got the cheapest model from Shenzhen, and I only paid $10 for it.. It's basically a combination of the cheapest webcam ever made and a cheap magnifier lens. My version only included an USB connector, a magnification wheel, and an LED brightness wheel, it doesn't have an screen nor a holder.It has some serious limitations, well, it's not a surprise given its price...- It only came with a plastic holder, which is completely useless. It's impossible to adjust the focus by shifting the microscope up and down accurately. Also, under high magnification, any small movement (including the movement by turning the magnification wheel) totally destroys the image, the microscope must be held in place firmly, and it's impossible with a plastic holder. However, a simple fix exists, spend another $10, and you can get an aluminum holder that specifically designed for these microscopes that fix this problem. Without it, the microscope is completely useless in a literal sense.- Serious overexposure and white balance problem. Although this $10 microscope included several SMD LEDs, and a potentiometer for brightness adjustment... However, once the LEDs are turned on, the webcam starts to overexpose the image horribly - it's impossible to see any fine details at all. Turning off the LEDs is a solution, but the lack of brightness also makes it impossible to see many fine details. Bad news for SMD inspection.- High latency. The software processing and buffering introduces ~500 ms latency, on my PC I've seen latency up to 1000 ms. Even moving the object while observing it is not easy. Fortunately, it's mostly just an userspace software buffering thing, on Linux, with "mpv av://v4l2:/dev/video0 --profile=low-latency --untimed" can skip most userspace buffering and I found the latency can be reduced to ~250 ms or so, good enough for observing a static object, but still not useful to see the image in real time.- Limited focusing. It's just a glorified magnifier, the object must be close to the microscope. On the other hand, when using a proper compound microscope, you can use a 0.5x object lens and a 20x eyepiece, allowing a massive 10 cm clearance.- No perception of depth. All mono microscopes have this problem, the inability to perceive depth makes it difficult to inspect the fine solder joints - is it really wetted and connected, or is it just a chunk of solder lying on the pads? It's difficult to tell.Nevertheless, it's just $20. If you know exactly what you are going to get, it can be a better-than-none item for PCB inspection when you don't have other tools. In my experience, using this microscope, you can see if the soldering is all goodafter the components are soldered on the board. But it's useless while you're in the process of soldering. Also, when the joints are not good, it's not possible to see the reason under such a microscope.Here are some photos I took with the microscope.(1) Inspecting reflow soldering of a 0.4mm QFN Ethernet chip (note the bridge on the bottom left, it's two Vcc pins, also see how the solder mask has been removed due to manufacturing limitations).(2) Force-soldering a 0402 resistor on a 0805 pad (cannot find the 0805 resistor anymore...)(3) 0805 LED on a devboard.(4) Bond wires (500x magnification) on the silicon of the previous LED.

author: niconiconi
author_rank: Frequent Contributor
timestamp: July 23, 2020, 04:02:15 pm
content: More images.

author: bob91343
author_rank: Super Contributor
timestamp: July 25, 2020, 12:06:15 am
content: You say you have one, one what?I am having trouble understanding the pics. They look reasonably sharp, but can you solder while watching the screen?The more expensive model might be better.

author: niconiconi
author_rank: Frequent Contributor
timestamp: July 25, 2020, 05:16:12 pm
content: QuoteI did not identify the model because it's meant to be a general comment on most $20 microscopes.Quote from: bob91343 on July 25, 2020, 12:06:15 amThen, please also read the words in the comment, which contains an elaborate answer to your question, not only just viewing the pics.QuoteIf you do not want to read the original comment, I'll quote some key points from it as a summary.QuoteQuoteQuoteQuoteQuoteTL;DR: It cannot be used during soldering due to the problems listed above. If you don't have other tools, these $20 microscope can be better-than-none for a fail/pass check on the results after soldering. If the result is good, you'll know it's good, as my photos have demostrated. But if the result is bad, you'll know it's bad, but due to the low image quality, you cannot identify the nature of a problematic joint.QuoteYes, although I don't own any of those, but I can imagine those should at least have a working exposure algorithm and better resolution in their cameras.A self-building possibility also exists - there are many vendors of "industrial camera" on the market. These cameras are general-purpose cameras in a standard cube form-factor for computer vision applications, magnification lens are often preinstalled (or can be installed later), and with a suitable holder and light source adapter, they can used as microscopes.The cost of a camera with lens and a separate camera holder is not lower than $70 (more like ~$100), and a computer is needed for video capturing.

author: bob91343
author_rank: Super Contributor
timestamp: July 25, 2020, 06:15:02 pm
content: The problem with all of these is that my hands are in one place and my eyes in another, so my dexterity is seriously compromised. Perhaps I can get used to it.The worst, for me, is to work with tiny stuff. My dad was a watchmaker and I never ceased to marvel at his ability to do these things, and without benefit of a microscope or our modern tools.For now, at least, I am not going to agonize over this. The project will have to wait. Working against that is my advanced age, with gradual deterioration of coordination and vision.

author: phil from seattle
author_rank: Super Contributor
timestamp: July 25, 2020, 06:49:45 pm
content: Something to consider as an alternative to a microscope is a magnifying visor. Really good ones are expensive (70-100 USD), cheaper ones exist and do work. I generally don't need a lot of magnification - 2X is often sufficient.Also, consider better lighting. I find that increasing the light significantly improves the visibility of tiny parts.

author: ebclr
author_rank: Super Contributor
timestamp: July 25, 2020, 08:18:38 pm
content: This microscope is amazing for electronicsTake a look on this videohttps://www.aliexpress.com/item/32803775348.html?spm=a2g0o.productlist.0.0.29ab2735S0oioA&algo_pvid=da094bbb-8d41-4c9c-977e-b9c912294db9&algo_expid=da094bbb-8d41-4c9c-977e-b9c912294db9-5&btsid=0ab6f82115957083969827771e358f&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

author: tggzzz
author_rank: Super Contributor
timestamp: July 25, 2020, 08:32:17 pm
content: Quote from: bob91343 on July 25, 2020, 06:15:02 pmWhat works is very personal, but things like this are a cheap and easy experimenthttps://www.amazon.co.uk/Rolson-60390-Loupe-Magnifier-Visor/dp/B001MJ0JW2/ref=sr_1_7?dchild=1&keywords=Magnifying+visor&qid=1595708994&sr=8-7I certainly find it very useful in many situations, at many angles, and with my ordinary glasses.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 25, 2020, 08:59:36 pm
content: Quote from: bob91343 on July 25, 2020, 06:15:02 pmPersonally for soldering, I like using a stereo microscope. Mine is made from old scrap bits and it has evolved over the years. A real mess. These guys are doing some much nicer mods. Have a look:https://www.eevblog.com/forum/reviews/my-amscope-microscope-camera-experience-microscope-mods/50/

author: cliffyk
author_rank: Frequent Contributor
timestamp: July 25, 2020, 10:40:56 pm
content: I worked in industrial safety for 10 years (6 for NIOSH) and have never seen a commercial precision assembly station with monocular magnifiers...

author: bob91343
author_rank: Super Contributor
timestamp: July 26, 2020, 04:21:54 am
content: I have a couple of those head mounted magnifiers but they are too flimsy and hard to adjust. And my head starts to sweat almost immediately. The Harbor Freight ones fall apart quickly. I also have my dad's loupes, one of which has a spring headband but again, not nice for me to use. He was good at making his eye hold a loupe, which I never mastered.So I am holding out for a stereo microscope with long working distance, variable magnification, good depth of field, room in its field for a fair sized board, illumination, and a few other niceties, all for $25. Yeah, right. Well okay, $35.

author: cliffyk
author_rank: Frequent Contributor
timestamp: July 26, 2020, 04:42:38 am
content: Yeah I have a couple of those hanging about, and even try to use them now and then. More often than not I find their "annoyance" factor outweighs any benefit...

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 26, 2020, 05:07:32 pm
content: Have you tried the magnifying glass app on your phone? If that's fine for you just buy a phone clamp and a small tripod.

author: arvidj
author_rank: Contributor
timestamp: July 27, 2020, 12:43:23 am
content: Quote from: phil from seattle on July 21, 2020, 09:59:04 pmI was wondering about that but got hung up looking for an inexpensive C mount macro lens. What did you use?Thanks,Arvid

author: phil from seattle
author_rank: Super Contributor
timestamp: July 27, 2020, 03:34:19 am
content: Quote from: arvidj on July 27, 2020, 12:43:23 amI'm not using a macro lens, just testing the camera. Using this one -https://www.amazon.com/gp/product/B07D66Z7FD/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1Paid $14. Surprisingly good. I've been considering this lenshttps://www.amazon.com/Monocular-8x-100x-43mm-150mm-Industry-Microscope/dp/B016NPUE9C/ref=sr_1_4?dchild=1&keywords=c+mount+lens&qid=1595820622&refinements=p_89%3AHAYEAR&rnid=2528832011&sr=8-4

author: robca
author_rank: Frequent Contributor
timestamp: July 29, 2020, 12:36:59 am
content: I'm getting to that crossover point where my age and the ever shrinking components made it impossible to solder.I looked at digital microscopes, and found them too cumbersome. Also, the last thing I wanted was to have my laptop or a monitor close to the area where I'm soldering (it's easy for a solder splatter to ruin a monitor)So I looked at digital microscopes on eBay and got an old Bausch&Lomb stereozoom 3 microscope. The most expensive part was the base/support, but if you are willing to build your own support you might be able to find something at a low cost. And a stereo microscope, unlike a digital one, gives you a 3D view with depth perception, especially if you add a Barlow lensI discovered two things:with a good stereo microscope, 5x to 15x magnification is all you need (I have 10x oculars, but a 0.5x Barlow lens, so the 1x-3x range of the zoom results in 5x to 15x magnification)With a good stereo microscope and "closed loop control in real time" (i.e. your hand/eye coordination with no lag), your hand precision increases multifold. I can solder 0402 components, while without microscope my hands would shake too much even for a 0805. A digital scope with a lag of even a few hundred msecs does not result in the same precisionI cannot recommend an optical stereo microscope strongly enough (get also a LED ring light with dimmer for optimal contrast)

author: bob91343
author_rank: Super Contributor
timestamp: July 29, 2020, 07:49:07 pm
content: Robca, I think you nailed it. I do have a microscope that I immediately put away as not being useful. I will take another look in light of your comments. It's traditional, with rack and pinion focusing and a tiny stage, not at all handy for soldering. I cobbled up an illuminator for it but even that's nothing to rave about.

author: kripton2035
author_rank: Super Contributor
timestamp: July 29, 2020, 08:22:00 pm
content: made with andonstar ADSM302

author: robca
author_rank: Frequent Contributor
timestamp: July 29, 2020, 11:54:13 pm
content: Quote from: bob91343 on July 29, 2020, 07:49:07 pmI originally got my B&L StereoZoom with the basic support as in the first picture. That would not work for soldering, and if you have anything similar, it would not surprise me if you gave up. I tried using the holder in a self made base, but not having a 3D printer or metal tools, I was not satisfied with the results. But it definitely can be done without spending muchI then found a boom support like the one in the second picture. I now can solder even boards inside their case (i.e. raised quite a lot), or use any type of PCB support, including rotating ones. The boom cost more than the microscope itself, but I don't regret buying it at allThere are also two types of oculars, the standard ones and the wide field ones (usually marked by WF). The WF ones are much better for soldering, and a must have if you have glasses (I actually I'm short sighted enough that I prefer using the microscope without glasses)If you have a B&L StereoZoom, there are also quite a lot of resources online to properly focus it and take care of it. Feel free to PM me if you can't find the docs (many used to be in a since abandoned Yahoo group)

author: bob91343
author_rank: Super Contributor
timestamp: July 30, 2020, 12:31:32 am
content: Mine is similar to this but 20x and 40x.https://www.amscope.com/sharp-forward-stereo-microscope-10x-30x.html?medium=tsa&gclid=Cj0KCQjwvIT5BRCqARIsAAwwD-S2IqE9v-qK0d2tegB3HWn3uEP6mL7YjHx-ohsV0-iSBo42IMYEnE0aAleGEALw_wcB&gclsrc=aw.ds

author: robca
author_rank: Frequent Contributor
timestamp: July 30, 2020, 03:50:25 pm
content: 40x will definitely be too much. There is a basic tradeoff between work area and magnification: the bigger the magnification, the smaller the work area. 20x is probably already too much and severely limits your work area. I do most of my work between 5x and 10x. The huge magnification might be one of the reasons why you were not happy with it the first time you tried. Together with a suboptimal stage, it results in a work area so small that most of the PCB and your soldering iron are out of focusYou might want to see if you can find a different set of oculars or a Barlow lens for your microscope, so that you can have a more practical work area.

author: bob91343
author_rank: Super Contributor
timestamp: July 30, 2020, 08:24:16 pm
content: robca you are correct. 20x is way too much. How can I change mine to afford a lower magnification? Either replace the eyepieces or the objective or both, but I need to know what size so it can fit.Once I do that, I will need to cobble up a support, as the little base it's on leaves no room for a reasonable circuit. I can buy a cheap flex lamp, remove the bulb, and mount the microscope on it, maybe.

author: robca
author_rank: Frequent Contributor
timestamp: July 30, 2020, 09:02:40 pm
content: I'm assuming your microscope comes with a 10x eyepiece. If not, the below needs to be adjusted accordinglyI don't know anything about the Amscope line, but one of thesehttps://www.amscope.com/instantsearchplus/result/?q=wf%205xwould reduce your magnification in half (10x-20x), assuming you have a standard 10x WF ocular now. You need to check what diameter are your current oculars, and buy the right 5x WF oculars. Probably you can find even cheaper ones on eBay, the challenge is that quality might be lower (but we are not talking about a precision instrument here anyway, so probably won't notice much difference. eBay 5x WF 30mm oculars cost ~$10 plus shipping for a pair (https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=eyepiece+5x+WF+30mm). Just check if those work size-wise. Modern microscopes tend to be either 30.0mm or 30.5mm, while my old B&L has a 23.2mm ocular diameter (common in the past). Some eBay listings give you the field of view (usually 20mm for a 5x WF), but that's pointless for your purpose: what matters is the diameter of the tube. A 30.0mm ocular can always be used in a 30.5mm microscope by wrapping something around it, but I would highly discourage it, since the alignment will suffer and even worse you might end up dropping dirt/particles into the optical path. Do not get the ones with the reticle: it might be helpful in biology and other sciences, but just an annoyance when solderingOculars are the cheaper option. Or you can look for the right size Barlow lens, 0.3x or 0.5xhttps://www.amscope.com/instantsearchplus/result/?q=barlow(as usual, there might be cheaper eBay options, but I wouldn't know what to look for, sorry). 0.3x would be ideal and make your microscope a 7x to 13x scope, perfectly in range. A 0.5x Barlow with your oculars would be identical to buying 5x oculars, just more expensive. In my case, having a Barlow lens had a couple of benefits: it added room to attach a ring LED light (B&L microscopes otherwise do not have anything for the ring light to "grab"), and also acts as a protective element for the more delicate optics in the head: if solder splatters or the head drops onto the work area, the Barlow lens would be damaged (and replaced) instead of the more delicate and irreplaceable internal lenses. Not sure if it adds benefits to your microscope, so not sure if it's worth the higher costEven with just the proper ocular you should be able to use your microscope with the current support, as long as the PCB is on the stage itself. A better support will give you more freedom, but I was able to solder perfectly well using my smaller support, as long as the naked PCB was on the stage itself

author: bob91343
author_rank: Super Contributor
timestamp: August 01, 2020, 02:58:26 am
content: My eyepieces are 30.5 mm. Looks like it will cost about $15 for a pair of 5x to replace my current 10x but I'm unsure if that's low enough magnification.I don't know where a barlow lens would go. The objective lens doesn't appear to be removable. It's marked x2 and x4.

author: robca
author_rank: Frequent Contributor
timestamp: August 01, 2020, 08:25:20 pm
content: The bottom lenses are x2 and x4, and with the original eyepieces result in 20x and 40x (10x times 2x = 20x)With the 5x eyepiece and the 2x lens, it would result in a 10x, which should be pretty usable and in the middle of my B&L range. I have a StereoZoom 4, which zooms from 0.7x to 4x, plus a 10x eyepiece, which would make it 7x to 40x, but with the Barlow lens becomes a 3.5x to 20x. I do mpos of the work around 10x, so you should be in range, and rarely I need 20x when I'm dealing with a particularly fine pitch chip (but as I said, at that magnification the depth of field is really limited: you can have either the soldering pad or the top of the pin in focus, no both at once, and you need to pre-position the soldering iron tip before looking into the eyepieceA zoom microscope is preferred when possible, since you have infinite settings between min and max, but your microscope with a 5x WF (don't forget the WF part) should be pretty good for most soldering work, and IMHO much better than any digital microscope. Given it's a relatively cheap investment to find out, I would highly recommend to get the 5x WF eyepiecesYou can then contact Amscope and see if they sell 1x and 3x lenses, which would give you all the possible ranges you need. Actually, if you could remove the 4x lens, I would try completely removing it. At he end of he day, a 1x lens is nothing more than a glass disk to prevent dust from entering the microscope body, so removing the 4x lens and using a 10x eyepiece would give you 10x with your existing eyepiece. Then with the 2x lens and a 5x eyepiece, and 5x with no lens, you'd have every range you need (5x and 10x)

author: bob91343
author_rank: Super Contributor
timestamp: August 01, 2020, 10:01:24 pm
content: Almost too much information! I don't think my eyepieces are WF but I don't see that mentioned in any of the eyepieces I see on ebay. Removing the objective is an option I must investigate. So far it seems to be part of the unit, although it's a different color. It must fasten somehow.Well looking upward into the objective I see two pairs of small lenses; each pair mounts with three screws but I doubt the assembly will come loose if I remove them. The two parts of the movable assembly are held together with four screws but two of them are covered partially by the objective assembly.

author: robca
author_rank: Frequent Contributor
timestamp: August 01, 2020, 11:35:06 pm
content: Are you searching for "eyepiece 5x WF" (no quotes)? I can find a lot of WF, like this onehttps://www.ebay.com/itm/WF5X-20mm-Eyepiece-for-Stereo-Microscope-with-Eye-Cups-Reticle-Mount-30mm-30-5mm/172590113071orhttps://www.ebay.com/itm/One-Pair-WF5X-Stereo-Microscope-Eyepieces-with-Rubber-Eye-Cups-Mount-30mm-30-5mm/273488118243,etc. Please note that I'm not suggesting those explicitly, just providing a link. You'd need to make sure that the sellers are reliable (the second one has a very high rating)Unless your current eyepieces have WF on them, it means that they are not WF. If you have 10x standard field, your filed of view further shrinks, making it even less usable. Here are Amscope lenses with the WF marked on themhttps://www.ebay.com/itm/AmScope-Pair-of-WF5X-Microscope-Eyepieces-with-Wide-Field-of-View-30-5mm-mount/400441156048(clearly, cost more)Amscope sells different Barlow lenses, so at least some of their scopes can mount a Barlow lens. I'm sure they would reply if you ask and provide your model number

author: bob91343
author_rank: Super Contributor
timestamp: August 03, 2020, 03:02:43 am
content: I have neither a model number nor a manufacturer other than the Variscope name/ Looking at the eyepieces, they are marked WF but are 10x.

author: jfiresto
author_rank: Frequent Contributor
timestamp: August 03, 2020, 07:48:28 am
content: Quote from: robca on August 01, 2020, 11:35:06 pmAmscope likes to prefix their eyepieces with WF and market them as "wide field", including those that are not, for example, their 30mm WF-10X/20 units. An eyepiece's field number suffix tells you the actual field of view, here, 20 for 20mm across at 10X total magnification. Wide field 30mm eyepieces start at 10X/22 and go as high as 10X/26.5. Beyond some wideness, you may see vignetting.