Stereo Microscope for a Beginner

[LeSquidNoir]

G'day all,

I have fond memories of using a stereo microscope in high school biology class, so now I've finally decided to bite the bullet and acquire one. It would be for general hobby use and I want to try and keep the budget below about $600 AUD (~$450 US) if possible. This is complicated by the cost of shipping to Australia (and also return shipping shipping if it's defective, which I'm led to believe can be an issue at this price range). Ideally the microscope would have a zoom function, LED lighting (I don't want to risk overheating any bugs I look at) and halfway usable magnification up to ~80x.

Here are some specific microscopes I've been looking at:

Cheapest thing that looks like a microscope
Optical Microscope:TLI-6C-W Stereo Microscope

Locally available, so I could test them in the shop
Bresser ICD 20x-80x
Optex XTL7045-T/T2 Trio Inclined Stereo Microscope
Saxon RST Researcher Stereo Microscope

Used microscopes (buying used is pretty daunting, so these are both "refurbished")
Olympus VMZ 1x-4x Stereo Microscope
Nikon SMZ-2 Stereo Zoom microscope (w/o stand)

Do any of these look decent for the price range? What kind of quality could I expect from them (especially compared to my Belomo 10x loupe)? What kind of other things should I be considering? Any advice or recommendations you could give me would be greatly appreciated.

Thank you most kindly.

[gekko]

Welcome to the forum. I'm afraid I don't have much experience with stereo microscopes, but I'm sure you'll get good advice here.

[Oliver]

Hello,

The microscopes in your link are all somewhat different and they can not be compared directly. You first have to define your preferences and "needs", but I admit that this is difficult to do if you intend to use them for hobby purposes. Ultimately it boils down to the simple formula: The best microscope for you is the one that you enjoy using the most and the one that you will actually use the most. It is better to have a low-cost (maybe even low quality) microscope used often, than to have a high-cost one sitting around unused. What I want to say is, that there is a strong subjective component also involved, and not only image quality. Having said that, it follows that I would highly recommend you to contact a local shop and test out different models (maybe even take them home for a week to try out, with the possibility to return).

halfway usable magnification up to ~80x

This already excludes several options in your links.
The Bresser Researcher ICD LED 20x-80x, for example, has 2 objectives (2x and 4x) and allows you to go up to 80x by exchanging the eyepieces (10x or 20x). This is not the same as having a continuous magnification/zoom. This microscope will then have the following magnifications: 20x, 40x, 80x.

The Optex XTL7045-T/T2 Trio has a variable magnification (continuous zoom) from 7x to 45x, using a single 10x eyepiece. If you want more, then buy separate 20x eyepieces (but I would say that 40x is really sufficient for most cases). 80x is only twice as much and other factors such as contrast might actually compensate lack of magnification.

The TLI-6C-W Stereo Microscope for AUD 300 is quite expensive. Search Amazon.com. This is also a possibility. Buy a cheap one first to gain experience and then move up.

Used scopes: OK if you know what you get. Get them from a shop (refurbished), not good if you buy it privately, cause they might not even know what they are selling you. Shop also gives you return possibility and warranty.

1. You said that you wanted zoom. Some of the scopes in your links do have a continuous zoom some do not. Some allow you to switch between 2x and 4x magnification by turning the objectives (x10 to produce 20x and 40x), others have a separate knob to turn to produce a continuous zoom. I have used both and I think that a continuous zoom is visually really impressive, and some of these also have much higher magnifications up to 80x. Some may argue that continuous zoom might not produce the same image quality (contrast and brightness) compared to the non-continuous type, because of the more complex optics involved. I would say that other factors (lens coatings, etc) might overcompensate this, however. Some high end scopes have continuous zoom and therefore I would guess that these might probably be also better in other respects (stability, objective diameter=brightness), but then this might depend more on the individual device.

2. Brightness: The larger the objective diameter the brighter the image. Important if you do not want to use a lamp, for photography etc.

3. Trinocular tube for attaching a camera. Really useful, but expensive. Photography really extends the options for the hobby. Otherwise you have to attach the camera to the eyepiece and then you can not view.

4. Portability vs stability. The heavier the more stable, but less portable.

5. Size of stage. The larger the more convenient for larger objects.

6. Eyepiece field of view. Small field of view makes it appear like looking through a tunnel. Larger field of view is visually more impressive. Field number is printed on eyepiece, but not always indicated in the specifications.

These are the things I would look out for.

Greets, Oliver.

[JimT]

Welcome LeSquidNoir. I also do not have stereo scope experience but if I were starting out I would definitely follow Oliver's advice. Best of luck and enjoy this forum.

JimT

[lorez]

Good day to you, sir.

It's too bad you are so far from so many sources of used microscopes. The best of the lot, on your list, is the Olympus VMZ. It is better that all the others in every regard.

The problems, as I see them are several. First, you are far, far away. Second, the scope is refurbished, but this is a term that has a million nuances. Problems with this scope are largely with the dry lubricants. The task is not an easy one so I am suspicious of how deep the refurbishment may have been. Third, are the replacement eyepieces, but they are old enough that they were probably made in Japan so that may not be a big deal. IF the coatings are still in good shape I would not worry about it. You may be able to ask the seller a few questions and then make an offer.

On the good side, all the mechanical aspects are brass and are very well made. This was a good microscope in the 1970s and possibly still is.

lorez

[Dale]

You found the right place for high class advice. I would take Lorez' advice for a brain surgeon if I needed one.
I have two nearly identical zooms, and comparing the same bug from one to the other I found that good glass
makes all the difference in the world, magnification power is over rated. You can mount a cheap adjustable ring light that will light your bugs perfectly. I don't examine live specimens. Ikea sells a very cheap led gooseneck
lamp that will add great flexibility to lighting challenges. I noticed the shipping is $90, and no saw sign of any
guarantee which makes me wonder if picking a scope you can actually try is a serious consideration.
Dale

[einman]

I have several stereoscopes both continuous zoom and non. I have Bausch & Lombs, Nikons, Amscopes, Swift, American optical etc.

First off, as mentioned by several individuals in one form or another, magnification without resolution is a waste. The quality of the glass makes a big difference. Recognize that magnification is reached via a combination of the eyepiece and the objective.

I am not familiar with the scopes you mentioned. I tend to only purchase used scopes and clean and align them myself. Rather than try and explain how to select a good used scope you can post one you may be interested in by one of the manufacturers I have listed and I would be happy to comment.

I did post some comparisons on the Yahoo amateur Microscope forum. I can re-post if you selections involve any of the scopes mentioned above.

[vasselle]

Bonjour.
Pour une loupe binoculaire il faut mieux rester sur des grossissements de 10 X a 40 X environ,car après image se dégrade et ça apporte pas plus en détails dans l'image.
La loupe que je possède est une Bresser Loupe Binoculaire Researcher ICD 20-80X.
Et je me sert exclusivement de la paire oculaire 10 X et les deux gross de objectif 2 x et 4 x et ces largement suffisant pour observer les détails et l'image reste très bien contrasté et nette.
Cordialement seb

[apochronaut]

Welcome to the forum. To add to the good advice above, a word of caution. Entry level microscope marketers, which includes probably all of the companies that infest the googled pages , always overstate magnification potential. Einman, mentioned this in another way, referring to empty magnification.
80X is very high for a modestly made stereo microscope. Resolution or sharpness of a lens or lens system is proportional to the brightness of the image and the brightness of the image is inversely proportional to the magnification. In short , you need a huge amount of light to illuminate 80X and the optics to produce crisp ,high contrast images are expensive to make. Extra lenses ,without concern for quality or precision can always be added to bump up the magnification and give the buyer the illusion that they are getting a lot for their money.

In practice, 40X is a more realistic measure of the usable magnification , a modestly priced microscope could achieve. If you really need 80X, you probably need to raise your budget, or buy a used higher quality instrument that was made and sold under conditions where no B.S. was tolerable.

[zzffnn]

Welcome LeSquidNoir.

Apochronaut is one of the experts here. I totally agree with him.

Some 80x are most likely 4x objective with 20x eyepieces. 20x eyepieces are usually dim, having a narrow field and difficult to use (low eye point).

I personally would use 15x eyepieces to push it up to 60x, if there is really such a need.

Also note that dissecting scopes with a common objective may offer better resolution that separate objectives.

Bausch and Lomb Stereozoom 7 have decent objectives above 6x. Their quality is said to be decent to good.

Depending on what subject, magnification or working distance you need, you can easily/cheaply go from 10x (2x NA 0.05 objective with 5x eyepieces) to 1000x (100x oil objective NA 1.25 with 10x eyepieces) using a compound microscope. Compound scopes offer better and brighter image quality than dissecting scopes in general. Their working distance (usually from <1mm to 50 mm) is much shorter than dissecting scopes (usually 50 mm to 150 mm). As depth of focus is reversely correlated with resolution (numeric aperture value), compound scopes also have much shorter depth of focus than dissecting scopes - you just have to give up depth for flat surface resolution and use stacking or other contrast enhancing optical methods.

[einman]

Here are some of my previous posts on another Yahoo forum:

I have purchased and evaluated several models of scope including the Nikon SMZ-2T, Bausch & Lomb stereozoom 7, Amscope, and World precision lens as well as Wild and Meiji models.

At magnifications at or below 40X the World Precision model ( chinese) and the Amscope( chinese) were comparable to the Bausch & Lomb stereozoom 7, Meiji and Wild and Nikon. The Wild was a bit crisper but unless you have the two side by side not that noticeable.

Moving above 40X the Meiji, Nikon, Wild and B&L models performed better.

However, I was quite surprised at how well the older B&L and the Amscope performed vs the Japanese brands.

The B&L is still an amazing scope especially given it has a magnification level up to 70X with a good working distance and without the use of auxilliary objectives.



The model Amscope i was using was their Model ZM-1T.

I still own a B&L stereozoom ( I had 4 at one time) and the Amscope ZM-1T .

For 20X and less I have a swift 80 series which, though also old, is very good.

It all depends on your budget and use.

I will say that if you decide to purchase a B&L stereozoom on E-bay be aware many of them have poor optics as they were used for soldering etc and the optics are cloudy and/or may have fungus or chemical deposits.

The one I have was near mint and had been serviced. DO NOT believe the seller when he says "refurbished by seller" if he cant answer basic questions regarding the microscope. For many they consider the scope "refurbished" if the wipe the dust off. Some don't even do that..they just lie.

I returned one B&L stereozoom to the seller explaining what was wrong with the optics etc. and he simply re-posted it with the same "re-furbished" title.

Most of the Chinese scopes only go to 45X without using higher mag eyepieces or auxiliary objectives. Using Auxiliary objectives generally improves magnification but significantly shortens the working distance. However you can go to 70X with a B&L Stereozoom 7 with 10X eyepieces and no auxiliary objective. The optics are still quite good you just need strong external illumination.

The problem with the B&L stereozoom 7 is the objectives permit much less light, especially at higher magnifications, than say a Nikon SMZ-2T, SMZ-U, or Olympus SZH. All of the aforementioned scopes allow magnification above 45X with the SMZ-U going to 75X, the SMZ-2T to 63X and the SZH going to 64X when using 10x EYEPIECES AND NO AUXILIARY OBJECTIVES.

I have done a LOT of comparisons between my stereoscopes. I purchased nearly all of my scopes for less than $250 each. I'm currently trolling for either an SMZ-U or an SZH at which time i will sell off one or more of my other stereoscopes.

[apochronaut]

There are two ways to evaluate a microscope; actual experience with one, or an accurate extrapolation based on specifications. It is always best to get an impression based on actal use and adding up many of those impressions gives a better possibility of an accurate extrapolation.

Thanks for passing those comparisons on, Einman. Many will find them useful and thanks for pointing out the working distance differences in the various scopes. Often that specification of a microscope, where by it's very nature, whether it be to accommodate thick subjects or those in need of manipulation as an absolute necessity, gets overlooked, when in fact it is one of the more important features.

One thing I would add is that usually , within a range of microscopes from a given maker, the optical designs become more advanced throughout the magnification range, with the more advanced models. So, an AO stereostar 569 for instance is not just a 30x microscope as opposed to the 60X of the stereostar 580 but the entire optical design is more basic in it and not up to the high resolution standards of the more research oriented model. That is one of the reasons that a high working distance , even at very high magnifications can be maintained in some of the higher end models. It also means, that if you only require 40X magnification, you are better off buying a microscope that can achieve 60X, than one that maxes out at 40X and on the used market, more often than not a higher magnification model can be found for an equivalent price to the lower magnification model, especially if brand adherence is thrown out the window.

Eyepieces. The concept of boosting magnification by boosting the eyepiece magnification has been practiced for centuries and is an important factor in the marketing of cheaper ranges of microscopes. This only has merit as long as two critical factors are met.

1) the N.A. of the objective or paired objectives is known and you do not exceed a magnification that is more than 1000X the N.A.

2) the higher magnification eyepiece(s) are of a more sophisticated design than the lower magnification ones. If you replace 10X huygens eyepieces with 15X huygens eyepieces you are in for a disappointment but if you replace them with a design( often of a proprietary nature) that incorporates an improved field , better planarity , light transmission, even better collimation then you have the possibility of being pleased with your increased capacity. Bausch & Lomb for instance made, for their stereo microscopes a very good series of 10X W.F. eyepieces. Not so good were the 15X. The same is true of the Wild M5 where the 10X rule. The 15X are rarely used on either. However, B&L also made a pair of U.W.F. 15X eyepieces that are one of the best , actually, I would say possibly THE best 15X eyepieces ever made. They were used in research and military applications mostly and also were super expensive. The standard 15X eyepieces on a stereozoom 7 don't really do it any justice but the U.W.F. 15X are a whole other thing. B&L also made self collimating 10X W.F. eyepieces, mostly for military applications where very high stereo magnifications are used in aerial surveillance----up to 240X. As the magnification increases, the precision of the collimation becomes increasingly more important. Optical deviation that is not apparent at all at 20X can be very apparent at 60X and at 240X ......unbearable, so a solution was to make a pair of eyepieces that could be manually collimated to compensate , as well as to compensate for the individual differences in the user's natural ocular differences. Fortunately, such accessories are often available on the used market, whereas such valuable tools would be prohibitively expensive if purchased new and not at all available for most microscopes.

[LeSquidNoir]

Gosh, there's so many awesome replies here I feel like a kid in a candy store!

Thank you (and merci) to everyone for all the advice/info/tips/comparisons. It looks like I have quite the learning curve ahead of me. I'm also getting the distinct impression that high magnifications can be complicated, if not problematic, so for now I think I should set my sights a bit more modestly in that regard.

I have decided to be bold and order one of the used microscopes I was looking at: the Olympus VMZ. I asked the seller some questions and they seemed confidant in their degreasing and re-greasing skills. I did some googling and it turns out they're a microscope servicing company that has a presence outside eBay, so (hopefully) they should be at the more reliable end of the used market. Either way, I now have an exciting wait until the VMZ arrives and I can test it out. Wish me luck!

[Rodney]

Sable camel hair brush set, ethyl alcohol, distilled water. The end result would be the removal of the distilled water from the face of the lens with a dry clean brush. And all distilled water is not created equal.
Out of the pack all the brushes need to be cleaned again with dish-washing liquid and rinsed multiple times. And cleaned some after cleaning.
Now you have no need to worry about any glue that holds the cotton wad to the q tip.

Rodney

[Rodney]

edit, oops, these brushes should have been under xylol xylene topic.
sorry

Rodney

[billbillt]

You can delete it here and re-post in the correct location...
BillT

[Rodney]

Thanks Bill, was able to remove the brush picture.

[LeSquidNoir]

My Olympus VMZ arrived today! I've been having a great deal of fun playing around with it. The image is crisp, the mechanisms all move nice and smoothly, and the 3D effect makes everything look awesome.

How accurately should the microscope stay in focus as the zoom is changed? If I get it in focus at 40x and then zoom out to 10x, the image goes out of focus enough that it needs to be adjusted (by lowering the microscope). The effect is much more pronounced going the other way: if it's in focus at 10x, then it will be completely out of focus at 40x (and need raising of the microscope).

Also, the visible areas in the eyepieces have a slight horizontal offset from each other. That is, when I centered a coin in the left eyepiece it appeared shifted to the left by about 0.9mm when viewed in the right eyepiece (see pictures). Is this normal? I imagine there'd have to be some sort of differences between the images in order to create a 3D effect.

Coin centered in left eyepiece:

Centering - Left Eyepiece (10x).jpg (51 KiB) Viewed 12203 times

Same coin in right eyepiece appears slightly shifted to the left:

Centering - Right Eyepiece (10x).jpg (52.41 KiB) Viewed 12203 times

[zzffnn]

Focus drift depends on the scope design. Some (especially older) scopes do that by design. Many new scopes don't do that - they have fix focus (called working distance) at around 100 mm (though some are fix at 50 mm some at 150 mm).

Offset effect is common to most dissecting scopes.

[LeSquidNoir]

Ah ok, thank you. So how much offset between the eyepieces is considered normal? Is there a point at which eye strain might start to become an issue?

I've also been looking into getting a cheap LED ring light, however I'm a little unclear on how to actually mount it to the microscope. The attachment thread on the VMZ seems to be about 60-61mm, but most of the ring lights I've looked at seem to screw on with a 48mm adapter which the light then attaches to (like this one). Can I fit any kind of ring light, or do I need to track down an extra large one or something? I'm rather a bit perplexed by all of this.

[lorez]

Focus drift depends on the scope design. Some (especially older) scopes do that by design. Many new scopes don't do that - they have fix focus (called working distance) at around 100 mm (though some are fix at 50 mm some at 150 mm).

Offset effect is common to most dissecting scopes.

With all due respect, I am going to disagree with all of this.

Over many years I have seen a lot of stereo microscopes, but never one where 'focus drift' was a design spec. So I wonder what the term means. A couple of things come to mind; first, the body of the microscope physically slides down on the stand. In the case of the VMZ this is corrected by adjusting the compression of the focusing knobs. Second, it may mean that the image is not staying in focus (parfocal) while the zoom is being changed and this may be a more serious (more difficult to correct) issue. Remember that the depth of field is much greater at the lower magnification than the higher so zooming from low to high may give the impression of losing focus, but what is happening is that the objectives are fixed on a much thiner plane and it may not be what was the original point of interest. If going from the higher to lower the field will increase and a much greater specimen depth will be in focus. If you see that you are losing focus as soon as the zoom is activated there is a problem with the parfocality of the lenses. This problem could have occurred as the scope was refurbished, or over time and was not corrected as the scope was serviced. When the scope is working properly the zoom will remain focused on a flat specimen such as a resolution target throughout the entire range.

As for the image appearing in each eyepiece, they should be exactly the same. Tolerances for alignment are very tight and if your coin photos were taken with a camera that was reliably centered in the eyepiece tube then you have a significant problem, but we cannot be sure that this is the case. Although your eyes will compensate for small alignment problems, over extended viewing you will certainly notice fatigue.

lorez

[zzffnn]

LeSquidNoir,

I read your post again. The view difference between your left and right eyepieces is indeed a lot more than what I consider normal. I would not expect the view to be exactly the same, but the difference should be very very minor. On my Swift dissecting scope, the difference is less than the thickness of one strand of hair. Some people may even call that identical. But note that my eye sight between left and right eye differs a lot and wearing glasses or not also changes things a bit.

I googled your scope's name and found that it has focusing mechanism on the left eyepiece. Did you try to adjust that and see if the difference went away? If I purposely mis-align my eye tubes by turning that eye tube focus to make, for example, my left tube a lot taller/longer than the right tube, then the view between left and right will differ a lot.

What I meant by "focus drift" on older scope design "being normal" "by design" is this:

For example, some vintage Spencer dissecting scopes (e.g., #58) have screw-on interchangeable objectives. If you screw on a 1.7x objective, you would have a working distance of 80 mm (focused point is 80 mm below objective). When you take off that 1.7x objective and screw on a 3.4x objective, then you get working distance of 40 mm. That is a "focus drift" of 40 mm and no parfocality is incorporated in that vintage design.

Your scope looks like a new design though, so focus drift should be minimal. How much drift is normal depends on the design. For example, with my Nikon Labophot 2 compound (not dissecting) microscope and Nikon objectives designed for Labophot, a focus drift of a few micron (a few small steps on fine focus) is acceptable and still considered to be within parfocal range (and focus drift between dry and oil objectives can be a bit more). You may need to read the service manual of your scope to find out.

Personally, if I like the image a scope produces and its ergonomics, considering its asking price, I would not consider focus drift a serious issue. There are, of course, nearly perfect scopes for demanding professionals, if you are willing to pay a few grands for it. Mantis and Wild are the brand names to look into in that case.

[gekko]

For what it's worth-- I think a practical, though very rough, test of whether the microscope is in satisfactory collimation: if when you focus on an object, then look away, then look again through the eyepieces and you see two partially overlapping images that quickly and automatically merge, or, worse, if you have to exert effort to merge the two images, then the collimation is off. Also, if you get tired or get a headache after you've been using the scope for, say, 30 minutes. But if you always see a single stereo image without effort and extended use does not cause problems, then the collimation is probably good enough (at least for you).