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If you just want to dip your toe into binocular microscope territory at minimal cost then keep an eye on eBay for BM-51-2.

This is a basic Russian binocular microscope with 8.75X magnification and mine has a clearance of 14cm between the plane of focus and the objective housing, so plenty of room to work. The optics are great quality and it's a robust piece of kit. No they're not on a par with the Wild M5 that is my default scope but they are a fraction of the price and still very usable and are more than adequate for precise oiling of pallet stones.

They often go for as little as £25 plus postage but at even £50 they are great value, I know that there are a couple on there now with astronomically optimistic BIN prices which they don't warrant, you just have to keep an eye on the auction listings.

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12 hours ago, Marc said:

If you just want to dip your toe into binocular microscope territory at minimal cost then keep an eye on eBay for BM-51-2.

This is a basic Russian binocular microscope with 8.75X magnification and mine has a clearance of 14cm between the plane of focus and the objective housing, so plenty of room to work. The optics are great quality and it's a robust piece of kit.

14cm is plenty. Some LED lighting would also help.

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  • 3 weeks later...

I purchased an Amscope zoom stereo microscope: model SM-4B.  If you watch, they have sales regularly, I got it for $351 for a Labor Day sale.  It's been great.  The nice stand costs more, but it's really convenient to be able to move it around and rotate it out of the way and then back.  It's also nice to be able to adjust the view from straight down to at an angle easily.  You can look straight down jewel holes or see a screwdriver in a screw without being obscured by your hand.

The zoom head has 0.7x - 4.5x magnification, and seems to be the same basic design as most zoom stereo microscopes.  You then get more magnification from the eyepieces, which are interchangeable and a standardized size.  It comes with 10x, but they range from 5x - 25x.  I think 10x is probably the most useful size.

Then you can put a barlow lens on the objective to change the magnification and the working distance, with less than 1x lenses increasing the working distance and depth of field. The eyepieces don't change the distance but the barlow lens does, while both change the magnification.  You need this if you want to get any tool in there other than tweezers from the side held nearly horizontally.  I use a 0.5x barlow the most but use a 0.7x some too.

You also need a light ring that attaches to the lens.  It's going to be too dark otherwise, especially as the higher magnification.  The LED ones don't cost much and don't get hot.

AmScope also sells the barlow lenses (48mm) and lights, but you can get them from ebay/amazon for about half the price.

With the 0.5x barlow it's possible disassemble a movement entirely while looking through the scope.  Which is what I've been doing.  Compared to the eye loups and optivisors I've tried, it's got a better field of view, is more clear, better light, and more comfortable since your head doesn't need to be nearly so close to the work and one can easily zoom in to take a better look at something.

I kind of wish I had gotten the more expensive trinocular model so it would be more convenient to take pictures, which has been fun to do.

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I picked up one of those soviet era stereo microscopes (8.75x) which was suggested earlier in this thread. It did not come with a stand but for just £14 it seems really decent and a stand is not that hard to make. The only slight flaw is that the inter ocular position does not have the required friction and flops around too freely, probably just worn I guess.

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That SM-4B looks great! I'm looking for something like that because my scope has no room to work. I can see just fine (it's a B&L) but I can't get any work done with it. Frustrating...

I particularly like the arm, so I could swing it over the work area, and out of the way after. I might go so far as to put it on a bearing, so it can swivel into position without moving much...

Currently $412.99 but probably worth that anyway.

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I've read through this entire thread at least twice now, and I'm sold on the idea of a stereo microscope. I'm torn between waiting to save up for a $600 or whatever new microscope of known quantity, or less than $100 on a used one. Those Russian guys sound fantastic, but the US doesn't have the same watchmaking tradition as the UK, and they're just not available here at the same level of affordability. I'm not completely sure what to look for though as I troll eBay trying to find something affordable. I know working distance is critical, and magnification between 4-40(max) is usable. Anything beyond that is bonus, but not really all that useful for watchmaking. Lighting is also a really nice to have, but something could always be put together externally. 

That's all fine and good, but most microscopes on eBay seem to be from sellers who stumbled upon the wreckage of a microscope tanker, gathered up the remains, and are trying to hock them for top dollar with nothing but badly lit photos and a disclaimer that they don't know if they actually work. How can I tell the working distance and range of magnification from photos?

I often see "10X" on the eye pieces, for instance, which is pretty obvious, but how interchangeable/standardized are eyepieces? Is 10X a max, or fixed number with a range? Are eye pieces easy to source independently?

Same with the main... objective? The lenses at the business end. Those are often also notated with "YX", where Y is a number and X is the letter X. They eyepieces might be interchangeable, but the business lenses seem much more specific, at least to a given manufacturer. I'm not even sure if or whether they can be swapped around. Is there a way to tell? Same question as above re: standardization/sourcing differently powered replacements.

I think there's a third lens sometimes that goes after the "business" lenses that further magnifies, or reduces magnification to gain working distance.

From there, make sure the eyepiece lenses times the business lenses are at least a usable figure, but what about a range of magnification? Is it fixed or adjustable?

I could go on, but the gist of the line of questioning is sort of a crappy used microscope buyers guide when presented with almost no information other than eBay quality photos.

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Modern microscopes (or dissecting scopes) usually use multiple lenses to enlarge an image.   10X (that is: "ten times normal") would be an ordinary eye-piece.  The objective lens (sometimes there are several on a turret -- a compound microscope) have different focal lengths (like lenses on a camera) and you choose the one that gives you the magnification that works best for you.   There are limits though.  In general, higher magnification means less light hitting your eye (assuming your light source is constant) and a narrower field of view.

So: "10X" is a fixed eyepiece that means "ten times normal."  No "zooming here."  However, zoom microscopes do exist.  Some scopes include a lens called a "barlow" which acts as a doubler (or some other increase, say 1.4x -- same for telescopes).

You change your magnification, by changing your objective, just like you could use a 28mm lens on a camera for a landscape photograph, but a 100mm lens for a portrait.  On a compound microscope, I doubt you could change the objective lenses cost-effectively.

Here's a good explanatory page (I have no connection to them, but they lay it out pretty well).

https://www.microscope.com/compound-microscope-parts

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check out ocasde.com  I've been following this thread and have looked at these microscopes and get tempted and then fizzle out but this time while researching I found this place. they have Amscopes at crazy prices. I ordered the AmScope SE305R-PZ-E for 99.USD !!! 30 day money back guarantee so I had to see what they are like. Free shipping and no sales tax to boot. It looks like the one on the Amscope site and doesn't seem like a knock off. I'll let you know when I get it.  

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4 minutes ago, martygene said:

check out ocasde.com  I've been following this thread and have looked at these microscopes and get tempted and then fizzle out but this time while researching I found this place. they have Amscopes at crazy prices. I ordered the AmScope SE305R-PZ-E for 99.USD !!! 30 day money back guarantee so I had to see what they are like. Free shipping and no sales tax to boot. It looks like the one on the Amscope site and doesn't seem like a knock off. I'll let you know when I get it.  

That might be interesting!  Have a link to the seller?

[Edit:  Duh.  I see you listed it.  No need to reply]

Edited by NewToWatches
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@martygeneDid you see that model only has a 4" working distance? Is that the sort of figure that can be manipulated by purchasing different (fittings)? Let me know how that works out. Seems like an avenue worth some serious exploration.

K. So the technical term for the uppermost set of lenses is eyepiece(s). Are these a standard size and easily interchangeable? Is one limited to a particular system or manufacturer? For the sake of learning, assume I have a pair of 10X eyepieces, and I want to reduce my magnification by half. Would a reasonable course of action be to find a pair of 5X eyepieces within the same system/manufacturer/standard size?

Same basic question for the objective lenses. These seem much more specific to a given model/manufacturer based on what I've been seeing.

Barlow lenses must be what has been mentioned before as being used in sub-1.0 powers to increase working distance. Does there need to be any particular provision on a given microscope to be able to use a Barlow lens? On the example @martygene bought/will buy, would it be possible to add a Barlow lens to it (I assume 0.5) to double the working distance? Is it the case that many AmScope models are essentially the same, but with different lenses in various places? Is it like.... I dunno... A car where there's a basic model, but different engines, options, and equipment can result in dramatically different uses. Like my truck is available as a dinky little fleet runabout that seats two, carries a light load, and little else, or a tow rig, or a luxury truck (yes, it's a thing), or an off road monster, etc.

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spectre6000  I may have made a mistake in ordering this one, The others that I looked at said an 8" working distance and, as I am want to do, I pulled the trigger without being very careful in reading all the specs. I wanted 8". ( don't we all? lol) If that is the case I will return it and find the Amscope that does have this space, but still buy it from this site. Thanks for the heads up. 

 

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Well... Good for me that I wasn't missing any opportunities with 4" WD microscopes. I thought the 8" was about ideal, if a touch on the long side. Sorry for the bad news, maybe it's not too late to change the order pre-emptively? Still, let us know when and what shows up regardless. That's a killer deal.

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I called my friend, who is a biology researcher, to get her take on this. She answered a lot of my questions. It looks like various lenses can be swapped around to make a 3.5-40X (as an example) into a 3.5-180X (again, semi-random numbers). This seems to be limited to particular systems, which may or may not be manufacturer or even product specific. I haven't dug in yet, but I think AmScope will likely be a safe catalog for being able to buy a decent microscope, and then swap out parts if/as needed down the road (within a reasonable amount of time).

Meanwhile, I dug into the site mentioned above. I was able to find some fairly high end microscopes for under a dollar... A lot are listed for $99 and a few a little less, and I found a few under a dollar, but for similar values ($0.99 for instance). Probably a typo. Probably wouldn't be honored, but I'd absolutely add one to the cart just to see if they deliver. The site itself looks a little... sketchy. Nothing too terribly overtly sketchy, but also too good to be true. Chingrish in a few prominent places, "About Us" doesn't say anything at all, "Contact Us" just has an email address from a different domain. I dug into the domain a little, and it was only registered 2 months ago. The domain in the contact email was registered a year ago. I forget who the main registrar was (anything specific to the actual owner is shrouded), but the registrar for the contact domain is GoDaddy. Same obfuscation. This isn't a bad thing, I do the same with my domains, but it's not helpful. Traffic to the site is minimal, it doesn't show up anywhere but the site itself, and the email domain has 0 traffic.

So... I'm thinking it's worth a swing. I'm going to check up on my credit card's fraud dispute policy and see what happens unless @martygene reports back first.

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The biology researcher's husband was out when I talked to her earlier. His work is a bit more homologous to watchmaking. He does ultra-high frequency, ultra-high precision electronics at a lab associated with CU and NIST in Boulder. He made the resonator (equivalent to the escapement) for the next generation atomic clock that will boost its accuracy by 10KX (that's horological, right?). I'm sure the microscopes at his lab are much higher end, but he personally has a double boom AmScope with 4" working distance in his home shop. We chatted a bit about what I'm needing, my down the road desires/ambitions (hunting tardigrades in the yard with my currently 1 year old daughter), and the limitations of that approach. This is definitely the way to go, assuming the site checks out. I told him the domain from memory over the phone (it's gibberish, and I may have misremembered it). He said the SSL was no good, but looking at it on my machine (without having to recall the domain from memory), and the SSL checks out. That may mean I told him the wrong domain and he didn't go beyond the warning page, or it could mean my filter's standards for acceptable SSLs are looser than his. His take was that it was too sketchy for his $99, but if I wanted to buy two, he'd pay for both in exchange for one of them once they arrived... I will be waiting as patiently as possible to see how it works out for you.

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@spectre6000, sounds like he has the same kind of AmScope stand I have.  It's more expensive than the single boom and non-boom stands, but I think it's worth it.  @Tudor, I do exactly as you describe, and move the scope out of the way when I don't want to use it.  The boom rotates freely, unless you lock it with a knob.  There is another locking ring under the boom on the vertical shaft that controls height.  The boom slides back and forth on a linear bearing too.  The head has multiple degrees of freedom, for tilt, rotation, additional height, etc.

Changing the objective lenses is something that is done for compound microscopes.  These are the kind used for looking at slides a millimeter from the lense, with one eye, at 1000X+ power.  Totally wrong kind of microscope.

For a stereo microscope the objective isn't swappable.  It's either fixed or has some zoom range, like 0.7x to 4.5x.

Multiply the base magnification of the objective by the eyepieces to get the total.  This is how a 0.7-4.5 zoom (like the AmScope models) becomes a 7x to 45x when combined with 10x eyepieces.

Eyepieces are semi-interchangeable.  There are different sizes and types, some more standard than others.

For a stereo microscope you want widefield eyepieces.  They will say often say "WF".  Non-widefield are for compound microscopes.  Totally wrong.

Then you have the size, or diameter where it fits into the eyepiece tubes in the scope body.  The AmScope uses 30mm eyepieces, which seems to be the most common size.

Eyepieces can also be high eyepoint or low eyepoint.  This is how far your eye should be from the eyepiece to get the correct focus.  High eyepoint lets you wear glasses (which you should do if you wear glasses).  They will often have an eyeglass icon on them.  Everything seems to be high eyepoint for stereo microscopes.

Then you've got a choice of magnification and there is 5x to 30x is available.  10x is standard.  Since the microscope objective doesn't get bigger, using higher magnification eyepieces is like camera digital zoom: it makes the picture bigger but doesn't add new pixels.  They also need more light and just seem to be more fiddly.  Less of sweet spot to get your eyes and more fiddly with focus.

Given that, there are a thousand compatible eyepieces for sale on amazon, ebay, aliexpress, amscope's site, etc.

Now, for working distance.  All of AmScope's zoom stereo microscopes have the same working basic distance!  And the Zeiss, Fuji, etc. are nearly the same too.  It's not an arbitrary value to designer can choose at will, but is based on the objective magnification.  So you've got no choice really.

But wait you say, "AmScope's different models clearly have different working distances in the specs!  That's got to be wrong!"  What's going on here is a Barlow lens.  This is large lens that screws onto the front of the objective.  The AmScopes use a 48mm thread and you can buy them from many places.  These change the magnification, choices are 0.5x, 0.7x (i.e., less magnification), 1.5x, and 2x.  The lenses that decrease the magnification also increase the working distance.  A 0.5x lens will cut the magnification in half while doubling the working distance, while the 2x does the opposite.

You want a 0.7x and/or a 0.5x for watch work if you want to do more than look at things or maybe use an oiler.

The AmScope kits with the larger working distance just include a 0.5 or 0.7 Barlow lens.  You can buy the same lens separately.  In fact, AmScope really has just one normal stereo binocular microscope.  Then there are 300 different kit combinations of that scope with different stands, eyepiece(s), barlow lens(es), lights, cameras, and so on.  BTW, the kit prices are strange.  Some are a much better deal than others.

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I started to ask when Chinese New Year was, because it bit me in the butt last year on a business deal. It combined with China shutting down for coronavirus, then we got shut down. Never did find a gap before the opportunity was gone...

I had some time last night, so I went through the entire ocasde site and looked at everything "microscope". They also have another brand that google tells me is a very similar level, but maybe slightly less versatile (less accessory choices). I forget the name, but it might have started with an O. I also went through AmScope's site and looked the other way. I didn't find anything new, but figured out more or less what you're saying about only really having a few models, and just blowing out a catalog with accessory combinations. I haven't completely figured out how the lineup works in terms of where the core is, and how the part numbers work such that I could "build" a microscope how I wanted in those terms though.

If the $99 scope turns out to be real (all of my fingers and toes are crossed), I'll probably buy a couple (maybe more than a couple). I'll get one for me, and one for the higher magnification stuff. At that price, it's a bit silly not to. It may also make sense to buy a few in the event they turn out to be factory seconds or something similar; swap parts around between them to get a good one, sell off the double second. 

Edited by spectre6000
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