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Lee

Stereo Microscope

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You're very welcome :)

I know you've made your decision, which is good. But I'd just point out that my own preference - and that's all it is - is for a zoom setup rather than having to change lenses. That way, you have infinite control of the degree of zoom between lowest and highest, and can adjust so that whatever you're looking at just fills the view.

After I posted the above, I checked at work, found an Olympus very similar to the eBay one I posted that sold for $142, and had a play with it using an anatomical specimen. Brilliant image, loads of working room, etc. I just removed the two little spring clips which just lift out.

Then I tried one of the LapSun ones with the cold light LED ring. They are used in one of the neuroscience labs - they use them when they're operating on lab mice and rats. For an inexpensive Chinese microscope, I was very pleasantly surprised. Seriously thinking of getting one now, to be honest. :)

But whatever works for you is great, and reading Lee's reviews of the Brunel one was very interesting. You could even have the base clamped onto the desktop or screwed down, to stop it tipping forwards, if the counterweight wasn't sufficient. Enjoy the world of miniature :)

Not being familiar with microscopes, could I ask...

If I was to get a zoom microscope on a standard base. Is it feasible to think I could remove it from the stand & then make a custom long arm stand to fit it 2? Or does the microscope have to be a specific distance from the specimen it's viewing? Or would the zoom take care of that? Ie.. If the original stand supported the microscope approx 70mm away from the specimen, could it be attached to my custom stand 250mm away from the specimen & still focus fine?

Regards

Dave

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Hi Dave :)

 

First, don't get focal length confused with zoom. The zoom, on a microscope, refers to the degree of magnification, while the focal length is essentially how far the bottom lens is from the object you're working on.

 

So when you FOCUS the microscope, it moves up and down, usually on a rack-and-pinion mechanism. When you ZOOM the microscope, the internal lenses change their configuration to increase or decrease the magnification factor, while the microscope itself doesn't move. And there's no need to change lenses with a zoom system.

 

Now, if you want to mount a microscope on a long arm (similar to the operating microscopes I use in surgery), you need a very strong mounting arm (the ones we use are multi-jointed on a VERY heavy stand) with enough counterweight to balance against the weight of the microscope itself PLUS the distance it is mounted away from the mounting point of the arm.  If you see what I mean.  The longer the mounting arm (i.e. the further away from the microscope itself the base of the arm is) the more counterweight you would need, OR a totally rigid mounting point.

 

Now where a lot of the expense arises in brands like Olympus, Zeiss (the ones I use at work are Zeiss), etc is in the optics that are designed to have a LONG focal length (using the term to mean working distance).  You will know from a watchmaker's eyeglass that the higher the magnification, the shorter the focal length, or to look at it another way (no pun intended) the closer you have to be to the work. Very expensive operating microscopes have working distances measured out to about 500mm or more, while maintaining magnifications up to 40x. And I can tell you, one cup of coffee before using one of those and your hands appear to shake like an earthquake!

 

The cheaper brands won't have the long working distance, but those advertised as stereo dissecting microscopes will have a reasonable working distance. The ones I linked to all have working distances of around 100-150mm at most.  But that is probably more than enough for what you need.

 

Is there any particular reason you want it on a long arm? The reason I ask is that there is usually plenty of room to work on watch movements etc under one of those dissecting microscopes. The LapSun one that our neurosciences lab uses has the benefit of a cold-light LED ring system as well. That's the one I think I'll get for myself. But I don't need it on a long arm.

 

Having just re-read your question (and apologies for the long-winded answer), the answer is no, you can't change the working distance of the microscope from say 70mm to 250mm. I assume you're talking about the vertical distance between the object and the lower lens - that's what is meant by working distance. If you DID want to mount the microscope on a longer arm, you'd need to mount the rack-and-pinion focusing system with the microscope, but also make sure that the microscope at half way up the rack is in focus. That gives you adjustment both ways.

 

The other thing to remember is that the eyepieces of microscopes like these are angled towards you, and you need to have the instrument at a comfortable height for you to lean slightly forward and have your eyes on the eyepieces. If you don't have that at a comfortable height, you will soon get a very stiff neck and a headache! (Said he, speaking from bitter experience).

 

Hope that all helps, and makes some kind of sense. :)

 

--
Pete, Brisbane
============
 

Edited by DrRock

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Hi Dave :)

First, don't get focal length confused with zoom. The zoom, on a microscope, refers to the degree of magnification, while the focal length is essentially how far the bottom lens is from the object you're working on.

So when you FOCUS the microscope, it moves up and down, usually on a rack-and-pinion mechanism. When you ZOOM the microscope, the internal lenses change their configuration to increase or decrease the magnification factor, while the microscope itself doesn't move. And there's no need to change lenses with a zoom system.

Now, if you want to mount a microscope on a long arm (similar to the operating microscopes I use in surgery), you need a very strong mounting arm (the ones we use are multi-jointed on a VERY heavy stand) with enough counterweight to balance against the weight of the microscope itself PLUS the distance it is mounted away from the mounting point of the arm. If you see what I mean. The longer the mounting arm (i.e. the further away from the microscope itself the base of the arm is) the more counterweight you would need, OR a totally rigid mounting point.

Now where a lot of the expense arises in brands like Olympus, Zeiss (the ones I use at work are Zeiss), etc is in the optics that are designed to have a LONG focal length (using the term to mean working distance). You will know from a watchmaker's eyeglass that the higher the magnification, the shorter the focal length, or to look at it another way (no pun intended) the closer you have to be to the work. Very expensive operating microscopes have working distances measured out to about 500mm or more, while maintaining magnifications up to 40x. And I can tell you, one cup of coffee before using one of those and your hands appear to shake like an earthquake!

The cheaper brands won't have the long working distance, but those advertised as stereo dissecting microscopes will have a reasonable working distance. The ones I linked to all have working distances of around 100-150mm at most. But that is probably more than enough for what you need.

Is there any particular reason you want it on a long arm? The reason I ask is that there is usually plenty of room to work on watch movements etc under one of those dissecting microscopes. The LapSun one that our neurosciences lab uses has the benefit of a cold-light LED ring system as well. That's the one I think I'll get for myself. But I don't need it on a long arm.

Having just re-read your question (and apologies for the long-winded answer), the answer is no, you can't change the working distance of the microscope from say 70mm to 250mm. I assume you're talking about the vertical distance between the object and the lower lens - that's what is meant by working distance. If you DID want to mount the microscope on a longer arm, you'd need to mount the rack-and-pinion focusing system with the microscope, but also make sure that the microscope at half way up the rack is in focus. That gives you adjustment both ways.

The other thing to remember is that the eyepieces of microscopes like these are angled towards you, and you need to have the instrument at a comfortable height for you to lean slightly forward and have your eyes on the eyepieces. If you don't have that at a comfortable height, you will soon get a very stiff neck and a headache! (Said he, speaking from bitter experience).

Hope that all helps, and makes some kind of sense. :)

--

Pete, Brisbane

============

Thanks Pete, it took abit of explaining. But I think I've got a slim grasp now ☺

The reason for long arm is.. I assume that in normal use I would be attacking the watch from the side, tweesers etc. However, for screwdrivers I'd need to be coming from above, so I naturally thought I'd need to have clearance above to put a screwdriver?

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Yeah - sorry for the long-winded explanation! :)

 

I doubt you'd be using a microscope for using screwdrivers - at least, not from above - your hand would block vision. And you'd need very short screwdrivers.

 

I guess if you really want to use screwdrivers, you could put a watch on its side in a holder, and approach from the side with the screwdriver. But the use of a microscope is probably a bit of overkill for that.

 

Now I'm most certainly no expert in the watch field, but I imagine most who use a microscope would be using it to (1) examine tiny parts, and (2) work on things like jewels etc. And for that, you'd be coming in from the sides with your instruments eg forceps, jewel picker uppers etc.

 

Anyone else who uses a microscope care to comment on what they actually use it for?

 

--
Pete, Brisbane
============
 

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I think you'll find that Mark is using a really good camera suspended vertically over the work, and with a macro lens that has a decent focal length (and therefore working distance). It would also have autofocus, if I'm not mistaken.

 

--
Pete, Brisbane
============
 

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I think you'll find that Mark is using a really good camera suspended vertically over the work, and with a macro lens that has a decent focal length (and therefore working distance). It would also have autofocus, if I'm not mistaken.

--

Pete, Brisbane

============

Your probably not mistaken. But in an ideal world that would be the kind of view I'd like the microscope to give me.

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I don't usually use my microscope in general disassembly or reassembly; for that I use a clip on magnifier attached to my glasses that has a lens for each eye so I retain stereo vision.

The microscope comes into its own for inspection, oiling, and hairspring work, where the higher magnification really makes a difference. It's also great for detailed cleaning and restoration on dials partly because of the magnification but also peering down a microscope cuts out all of the peripheral distractions so your total focus is on the job in hand.

 

I do use a conventional loupe as well but that tends to be for inspection only as I find working without the ability to properly judge distance is less than ideal. Also, I work at desk height rather than bench height (something that I have to sort out as it's not so good for my back) which means that I am above the work, where the screw drivers need to be, so higher magnification loupes (with correspondingly closer working distances) are less than practical. As and when I eventually get a bench sorted out loupes may become a more viable proposition. What I have in mind is to have the working surface more or less at shoulder height when I am sitting upright. This would place the work in front of my eyes not below so there would be no competition for space with tools.

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At the risk of sounding facetious - my wife just bought one of these:

 

http://www.zeiss.com/meditec/en_de/products---solutions/spine-surgery/surgical-microscopes/opmi-pentero-900.html#highlights

 

But just in case you think I'm a lucky fella - she runs the operating suite at one of the biggest hospitals here - and the one where I operate. This is very similar to the one I use.

 

Oh - in case you were thinking of buying one, the working distance, even at full magnification, is about 535mm.

 

Oh yes - the little matter of the cost.... $1 change from $400,000  ;)

 

Wonder what it would be like to work on a watch under one of those, instead of somebody's brain arteries?

 

Sorry - couldn't resist it :)

 

Personally, I'm going to get myself one of those LapSun jobs for $340-odd dollars. I just love working on tiny little things!

Edited by DrRock

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Wonder what it would be like to work on a watch under one of those, instead of somebody's brain arteries?

 

You don't have to be a brain surgeon to work on watches, but it helps!

Sorry - couldn't resist it :)

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At the risk of sounding facetious - my wife just bought one of these:

http://www.zeiss.com/meditec/en_de/products---solutions/spine-surgery/surgical-microscopes/opmi-pentero-900.html#highlights

But just in case you think I'm a lucky fella - she runs the operating suite at one of the biggest hospitals here - and the one where I operate. This is very similar to the one I use.

Oh - in case you were thinking of buying one, the working distance, even at full magnification, is about 535mm.

Oh yes - the little matter of the cost.... $1 change from $400,000 ;)

Wonder what it would be like to work on a watch under one of those, instead of somebody's brain arteries?

Sorry - couldn't resist it :)

Personally, I'm going to get myself one of those LapSun jobs for $340-odd dollars. I just love working on tiny little things!

Wow looks fantastic. Your wife & my wife must have been chatting, because mine to bought me a gift6d9468b40bc911d8728baec7c573042f.jpg she also managed to get $1 change. Unfortunately it was from $4 he he

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Heheh - good point Marc :) And Dave - simple is sometimes best!

 

Sorry if my post came across as facetious. Sometimes my lame attempts at humour or irony can do that.

 

I've ordered one of those $340 LapSun scopes. There are others on eBay, but many have elevated bases, while the LapSun has a flat one. Also, I'm familiar with the LapSun as there are several in the lab at work as previously mentioned. While obviously not of the same quality as a Zeiss or Olympus etc, they are more than good enough for the scientists who are doing microsurgical procedures on mice. And for $340, they seem like a steal.

 

--
Pete, Brisbane
============
 

Edited by DrRock

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Heheh - good point Marc :) And Dave - simple is sometimes best!

 

Sorry if my post came across as facetious. Sometimes my lame attempts at humour or irony can do that.

 

I've ordered one of those $340 LapSun scopes. There are others on eBay, but many have elevated bases, while the LapSun has a flat one. Also, I'm familiar with the LapSun as there are several in the lab at work as previously mentioned. While obviously not of the same quality as a Zeiss or Olympus etc, they are more than good enough for the scientists who are doing microsurgical procedures on mice. And for $340, they seem like a steal.

 

--

Pete, Brisbane

============

 

 

Can you post a link to the LapSun you purchased?

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Hi Blake - indeed I can. It's the middle one in my post on the previous page, but here it is again:

 

http://www.ebay.com.au/itm/7X-45X-Industry-PCB-Inspection-Dissecting-Zoom-Power-Stereo-Microscope-LED-Lamp-/111349298384?pt=AU_Business_Industrial_Medical_Scientific_Equipment2&hash=item19ecef74d0

 

LapSun is the company that sells them - and the guys in the lab at work call them LapSuns. But as far as I recall, there isn't actually a brand name on them. They're probably a generic thing made in a Chinese factory, and possibly rebranded by other sellers.

 

--
Pete, Brisbane
============
 

Edited by DrRock

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Influenced by Lawson's post  'Carl Zeiss - Eye Mag Pro' I bought a cheaper 6x 350mm pair of Galilean binoculars from China.

 

post-374-0-50304400-1433352956.jpg

These are intended for dental use but any dentist trying to use a 6x magnification mutst have control of the head position far better than I can manage. The viewed object was wobbling by about 50% of the 45 mm field of view.

 

The optical quality is excellent and so I have turned them into a binocular microscope using a heavy duty flexible support with standard end pieces as sold for microphones.


post-374-0-86817500-1433352925_thumb.jpg

 

Here in the bench mode with a Benson Aquatite movement - ample working distance.
 

post-374-0-35122300-1433352938_thumb.jpg

The only work that was needed is shown: a support that fits firmly into the mike clip and a pair of eye cups with

adaptor rings to match the eyepieces of the binoculars.


post-374-0-87573400-1433352944_thumb.jpg

 

Here mounted on my lathe base-board for some micro-drilling.
 

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The support was made out of 30 mm ebonite rod turned down to 22 mm to fit the clip and cut out half-round at the base, then drilled to match the holes in the binocular bridge.

The Zeiss eye cups are from the seller jameslee on eBay. I had to adjust them with short inserts to reduce the inner diameter to that of the binoculars.

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