Author Topic: Digital microscope  (Read 5885 times)

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Offline kripton2035

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Re: Digital microscope
« Reply #25 on: July 29, 2020, 08:29:38 pm »
 

Offline robca

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Re: Digital microscope
« Reply #26 on: July 29, 2020, 11:54:13 pm »
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.
I 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 much

I 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 all

There 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)


 


Offline robca

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Re: Digital microscope
« Reply #28 on: July 30, 2020, 03:50:25 pm »
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 focus

You 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.
 

Offline bob91343Topic starter

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Re: Digital microscope
« Reply #29 on: July 30, 2020, 08:24:16 pm »
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.
 

Offline robca

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Re: Digital microscope
« Reply #30 on: July 30, 2020, 09:02:40 pm »
I'm assuming your microscope comes with a 10x eyepiece. If  not, the below needs to be adjusted accordingly

I don't know anything about the Amscope line, but one of these https://www.amscope.com/instantsearchplus/result/?q=wf%205x would 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 soldering

Oculars are the cheaper option. Or you can look for the right size Barlow lens, 0.3x or 0.5x https://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 cost

Even 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
 
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Offline bob91343Topic starter

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Re: Digital microscope
« Reply #31 on: August 01, 2020, 02:58:26 am »
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.
 

Offline robca

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Re: Digital microscope
« Reply #32 on: August 01, 2020, 08:25:20 pm »
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 eyepiece

A 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 eyepieces

You 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)
 

Offline bob91343Topic starter

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Re: Digital microscope
« Reply #33 on: August 01, 2020, 10:01:24 pm »
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.                                                                               
 

Offline robca

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Re: Digital microscope
« Reply #34 on: August 01, 2020, 11:35:06 pm »
Are you searching for "eyepiece 5x WF" (no quotes)? I can find a lot of WF, like this one https://www.ebay.com/itm/WF5X-20mm-Eyepiece-for-Stereo-Microscope-with-Eye-Cups-Reticle-Mount-30mm-30-5mm/172590113071 or https://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 them https://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
 

Offline bob91343Topic starter

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Re: Digital microscope
« Reply #35 on: August 03, 2020, 03:02:43 am »
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.
 

Offline jfiresto

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Re: Digital microscope
« Reply #36 on: August 03, 2020, 07:48:28 am »
... 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....

Amscope 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.
« Last Edit: August 03, 2020, 07:52:16 am by jfiresto »
-John
 


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