comparing uses, features, brands, and cost
© 2014 by KV5R. Rev. June 1, 2014.
This article introduces the decision-making process and research involved in purchasing a microscope. We’ll discuss types, needs, desires, and interest; features and terminology; brands and vendors; and consider performance versus price. Please remember that the author is not an expert in the microscope manufacturing industry, and what follows are simply his impressions and opinions derived from on-line research and shopping. Readers are encouraged to do their own research prior to any purchase.
Defining Expectations, Needs, and Desires
The first questions are, What do we want to do with a microscope? What are our main interests? While the possibilities are nearly endless, here are a few suggestions:
- Make field observations of small things and/or pique the interest of young children — consider a good pocket microscope.
- Examine and photograph small things like insects, stamps, coins, and electronics — consider a usb digital microscope.
- Explore the details of small opaque objects; things you can see, but need to see in detail — consider a stereo microscope.
- Explore the world of invisible (1μm–1mm), semi-transparent objects such as pond critters, cells, and tissue structures — consider a biological compound microscope.
- Examine bacteria, viruses, cell details such as DNA, nanotechnology, and other things well below 1μm — consider an atomic force or electron microscope (≈$5,000 and way up). Note that while most bacteria are visible with a light microscope, they appear only as tiny, wiggly dots and rods at 400–1000x.
Most amateur microscopists will want an advanced educational-grade compound biological light microscope, something about like what they used in high school or college. Fortunately, these are now available for about $150–$650, and one may expect to spend at least $200 more for a useful collection of accessories and lab supplies. As stated in the previous article in this series, these are styled and designed to handle like lab-grade microscopes, but use much cheaper (but usually quite sufficient) optics. I would not consider any model that does not have four objectives, a mechanical stage, an Abbe condenser, and an LED light. The lowest-priced one of that description is currently (May 2014) the AmScope M620 (monocular) at $170, or the B120 (binocular) at $250. Add to either of them a 1.3MP imager ($100), and a set of plan objectives (≈$300) and you’ll have a microscope very comparable to many units costing twice that amount or more.
We’ll consider costs and brands below, but first let’s cover a few general things about shopping for microscopes.
Microscope Types, Quality Ranges, and Specialty Features
There are several main types, with several sub-types for various purposes, that may be used in the hobby. (click images for more info)
USB Digital, ≈$47
Stereo Microscope, ≈$145
Pro Microscope (≈$600)
- Toy — meant for younger children. Look for simple controls and durability. Lots of fun. $10–100.
- Pocket — these small, simple microscopes range from toys to serious field instruments, and are great for microscopists on the go. The better ones have rechargeable LED lighting and 20–40x zoom.
- USB handheld digital — not to be confused with USB microscope cameras/imagers, these are essentially a USB web-cam imager combined with simple microscope optics. The better ones will do about 50x magnification, but as with all digital imaging devices, look for mega-pixels (1.3MP for live USB-2 viewing, 2MP and higher for still photos), not just magnification. See Celestron 44302 and Plugable USB2-MICRO-200X on Amazon.
- Stereo — for 3D viewing of solid opaque objects with reflected light. Total magnification is usually 10x–40x or 80x. Useful for small insects, dissection, gemstones, electronics and other small assemblies, quality-control inspection, etc. These range from hobby/educational to scientific/industrial optical instruments. Decent ones start at around $125, or about $225 with a 1.3MP digital imager. Basic models have only incident (top) lighting, while better ones have both incident (top) and transmitted (bottom) lighting. Still better ones (starting around $500) will have LED ring lighting, larger stands, zoom optics, and trinocular heads.
- Biological (aka compound) — for viewing semi-transparent specimens (usually biological) with transmitted light. Total magnification is usually 40x–400x or 1000x. Useful for pond critters, cells, plant and animal tissue structures, etc. They require a large assortment of accessories such as slides, coverslips, and tiny tools; and various lab-ware and lab supplies for specimen preparation. These are sometimes called “compound” microscopes, though technically speaking, any microscope with more than one stage of magnification (e.g., objective and eyepiece) is “compound.” Note that, though not optimal, a biological microscope may be used like a stereo microscope (for viewing flat opaque objects) simply by using the 4x objective and couple of bright top-lights. I use a pair of little 50-watt halogen lights ($10) positioned to each side of the stage. It is also possible to dabble in fluorescence microscopy (with a UV flashlight and some fluorescent marker inks), as well as DIY darkfield and polarized microscopy.
- Digital — some vendors have models they call “digital” microscopes, usually meaning that it has a built-in imager, not one that that is added to an eyepiece or camera tube. Some of them even have a small color display right on the instrument, for classroom viewing without need of a computer.
These are common terms related to the quality, precision, and complexity of stereo and biological microscopes.
- Student microscopes — these are somewhat better than toys, and are targeted toward intermediate school science classes, home-schoolers, and casual amateur microscopists. They will usually come with 3 objectives (4, 10, and 40x), 1 or 2 eyepieces, and a simple fixed condenser lens with a rotating pinhole iris wheel. The stage will be a simple one with leaf-spring clips or (better) an add-on mechanical (vernier) slide holder. ≈$75–$150.
- Advanced student microscopes — these are somewhat better (having a mechanical stage and Abbe condenser), and are targeted at high school and college students. They are also well-suited to the amateur microscopist, the farmer, gardener, breeder, beekeeper, brewer, and even some medical purposes. They are typically built with lab-grade-style frames and controls, but with much lower cost optics. ≈$200–$800. They typically use industry-standard DIN optics and can be upgraded with better objectives (usually plan), a phase contrast kit, darkfield condenser, etc. As a minimum, look for four objectives, a double-layer mechanical stage, LED light, and Abbe condenser with iris diaphragm and filter holder.
- Some vendors list certain models and lines by profession, such as “veterinary microscopes”, as if to imply they are professional-grade. Professionals should buy the best microscope they can afford, based on its intended use. However, any $300 microscope will suffice for parasitology, and a $650 phase-contrast upgrade will suffice for hematology and cytology. The old paradigm and tradition that such uses require multi-thousand-dollar instruments is simply no longer applicable.
- Lab-grade (aka clinical, medical, research, etc.) — these combine high-precision frames, parts, and controls with expensive optics. ≈$1000–$6000+. Note again that many professional applications do not require such high-end microscopes. Lab-grade microscopes my be further subdivided into veterinary, medical, industrial, and research-grades, though such differences are not well-defined, and vary by manufacturer and vendor, with lots of overlap.
- Darkfield — a high-contrast illumination technique that eliminates most light from the background. As a microscope type, the term refers to any microscope with a darkfield condenser or patch-stop filter. Darkfield, as opposed to brightfield, is where the transmitted light beam is prevented from directly reaching the objective, so the background of the image is dark instead of bright, providing amazing contrast. The only light reaching the objective is scattered into view by the specimens (and sundry detritus), and they stand out against the dark background. It’s the same effect as seeing dust in the air in a dark room with a bright beam of sunlight coming in through a small hole. Looking across the beam, you see the dust in the beam illuminated against the background of dark room. Any microscope with a filter holder below the condenser may be used (at low-to-medium powers) for darkfield viewing by placing a “patch-stop” in the filter holder. The stop is simply a filter-sized disc with an opaque disc in the center and a clear ring (annulus) surrounding it, which creates a hollow cone of light that misses the objective. The spot must be sized according to the objective being used, so most amateur microscopists will make several patch stops for darkfield observations. I made mine with overhead transparency sheet, black electrical tape, and a circle cutter, and they work quite well.
Rotifer in darkfield
- Phase Contrast — an illumination technique for viewing transparent specimens by detecting the difference in refractive indices. As a microscope type, the term refers to a biological microscope equipped with phase contrast objectives and their matching condenser annuli. Any microscope with standard objective and condenser mounts may be upgraded to phase contrast capability with a phase contrast kit for ≈$350–$750. They contain “phase plates” in the objective lenses and matching condenser annuli that allow visual differentiation of transparent cells in vivo, without staining, and are commonly used in cytology and hematology labs. Unlike darkfield, it isn’t practical to make DIY phase contrast components, because of the tiny precision phase plates inside the objectives.
- Polarizing — an illumination technique using a pair of linear polarizers to examine birefringent materials, such as crystals and plastics. As a microscope type, it refers to any microscope equipped with two crossed linear polarizers. The more expensive ones have a round rotating stage with angular graduations (a goniometer stage), allowing the operator to precisely determine the angles of polarized light relative to the sample. On the amateur side, one may purchase a couple of linear polarized filters (≈$10), placing one below or atop the condenser, and the other atop the slide or eyepiece, which will produce spectacular results on common things like a saturated citric acid or epsom salt solution that’s allowed to dry and crystallize on a slide. Note that most camera lens polarizers will not work because they use circular, not linear, polarization.
Citric acid in polarized light
- Infinity Plan — an optical design that has a parallel (not converging) region in the optical path, allowing the insertion of special components into the optical path without affecting focus. Microscopes with infinity optical systems are considerably more expensive and may be upgraded to epi-illumination for fluorescence or metallurgical applications.
- Episcopic (epi) — a reflected illumination technique that inserts the light into the optical path using a beam-splitter mirror above the objective. Used in metallurgical and fluorescence microscopes, the light shines right out of the objective lens, reflects off the specimen, then goes back through the same lens, through the beam-splitter, and to the eyepiece.
- Inverted (optics are below and light source is above) — these are typically used for viewing tissue and bacteria cultures, right through the bottom of the culture dish.
- Other high-end specialty microscopes include differential interference contrast (DIC), surgical, industrial, and many others. These are complex optical instruments, and are very expensive.
Considering the Costs
Before one thinks that microscopy needs to be expensive, consider that the $200 microscopes of today are far batter than the very best that pioneers of microscopy had for some 300 years, yet they discovered parasites, cells, biological structures, biochemistry, and even bacteria, greatly adding to science, medicine, and the average human lifespan.
The price of a microscope is largely based on two things: (1) the quality of its optics, and (2) the reputation of its name. Indeed, many low-end models come out of the same factory at widely divergent prices, depending on the name the vendor places upon it. Also, some vendors sell different quality lines under different brand names, and even some of the most expensive brands use certain parts contracted in the same factory that also makes much cheaper microscopes. If you look at enough advertising photos, you will notice that a great many brands and models, particularly in the lower- to mid-price range, are using the same frames, bases, lamps, stages, and condensers. What you can’t see, without actually using it, is the quality of its optics.
Inexpensive microscopes use 3 or 4 achromatic objectives, which are fine for casual viewing, where you aren’t too concerned about exact focus near the edges. For micrography, where the entire field of view may be examined, it’s better to invest in a mid-range microscope with plan (PL) objectives. These microscopes start at about $600, but as an upgrade, a set of four plan objectives start at about $300, though if you leave off the 100x, you can get the 4x, 10x, and 40x plan objectives for about $150–$180.
Cost-wise, ranging from toy to pro, microscopy is comparable to regular digital still photography, and lot less than many other hobbies. As hobbies go, amateur microscopy is a lot cheaper than classic cars, bass-boats, and even amateur radio, where $3,000–$12,000 HF transceivers and $4,000 towers are not uncommon nowadays. The good news is that the amateur microscopist can do a lot with a $250 microscope and imager.
As we will see in the next article, accessories and supplies will substantially add to the overall costs of biological microscopy. However, if you shop carefully and avoid expensive lab-grade certified stuff, $250–$350 or so, plus the microscope, will set you up with a nice little lab where you can enjoy years of amateur microscopy.
Just like photography and many other things, the price rises very steeply at the last few percent of performance. For example, few people can tell the difference between photos made with a $500 consumer DSLR and a $5,000 professional camera. Likewise, a $500 home entertainment center is, for most people, no different than a $5,000 audiophile’s dream system. So it is with microscopy—you can do almost as much (and have just as much fun) with a $500 microscope as you would with a $5,000 pro model, and if you’re not a professional microscopist, that extra 9x cost is perhaps 3% performance and 97% bragging rights.
Bear in mind that optical performance is not linear to price; it’s a very steep curve. For example, let’s say we have a $400 microscope with a set of four achromatic objective lenses, the exact replacements of which may cost $200. If we then compare a set four achromats at $100 (on a $200 microscope), the optical quality is likely to be slightly lower, but only 3% lower, not 50% lower. On the other hand, a $400 replacement set may be 3% better, not 50%. From what I have seen, the $100 set of four is okay for casual viewing, but not quite satisfactory for the serious amateur or photomicrography, where a $300 set of plan objectives is considerably better.
Of course, the above percentages are just rough examples, as every lens brand and model is different. As for the really expensive brands, I have no basis for comparison other than looking at on-line photos, but I doubt that very few people could look at two images of the same specimen made by 40x objectives and determine whether one was made by a $60 objective or a $600 objective. This is simply because recent inexpensive lenses from China and Hong Kong are very nearly as good as their expensive Japanese and German counterparts, if you go slightly beyond the lowest grade (e.g., $35 40x objective) that are supplied with many lowest-cost brands and models.
Brands to Consider
Note: When I refer to Chinese imports, it is with no disrespect. Chinese manufacturing is very efficient, and quality may range from very poor to very good, depending on the wholesale buyer’s specifications and quality control. There is nothing wrong with purchasing Chinese-made products, if you remember that much research may be required to determine which wholesale buyers are specifying the better-quality lines of products. Indeed, there is nothing wrong with buying from the the lowest-cost line, if minimal cost is your goal.
Considering only the range of models suitable for the amateur microscopist, here’s a few things I noticed while shopping:
- AmScope, Omax, Omano, National Optical, and many others are all selling the same lines of Chinese-import models. AmScope currently has the lowest prices for microscopes in this range — but it’s hard to compare them by brand, because the same-appearing model may sell from one brand with slightly cheaper optics, while another at higher cost may have slightly better optics, or slightly better quality control. On the other hand, just because it’s more expensive does not necessarily mean that any part of it is any better—some brands simply have a little higher mark-up. You really can’t tell without directly using and comparing them.
- Motic is in the more professional ≈$750–$3500 range for the biological models. They appear to be among the best of the Chinese microscopes, and are very popular with serious amateur microscopists.
- Moving up the scale, we find Meiji Techno, from Japan. Meiji occupies the ≈$1500–$4000 range of lab-grade biological microscopes, and is Japan’s third-largest professional microscope manufacturer.
- At the top of price and performance is Nikon, Olympus, and Zeiss, who make no-compromise lab and research-grade instruments in the multi-thousand-dollar range. However, they also offer lower-cost models suitable for the serious amateur. If you want the comfort and bragging-rights of a highly-respected brand name at a reasonable cost, perhaps consider the Nikon Eclipse E200 series, at ≈$1000–$1800.
For the student or amateur microscopist, AmScope provides the best value, although one may soon wish to upgrade to plan (PL) objectives, particularly for micrography. For example, I ended up with the AmScope M620, which was $160 (in 2013), comparing feature-wise with several $350+ units. Considering that it has two eyepieces, a dual-layer mechanical stage, Abbe condenser, and LED lighting, the four objectives must be fairly low-cost achromats. They do work quite well, and I have lots of fun looking at pond-critters and such, but I quickly became dissatisfied with their photographic performance, and am considering a couple of plan objectives (10x and 40x). So the bottom-line is that I will have a very satisfactory microscope for ≈$300 that is virtually identical to several $550 units. I could have bought a $550 microscope in the first place, and still needed better lenses. I may do a comparison in a later article, with photos.
One caveat about the lower-cost imports is that they all seem to be made in the same factory, but are marketed under many brands at a wide range of prices for essentially the same models. Another is that they usually do not provide service or support (beyond warranty replacement), or service and parts manuals, so they are essentially “throw-away” consumer devices, much like consumer cameras, computers, and televisions in the same price range. This may or may not be a concern, depending on how much you pay for it. Most do have a 5 year warranty.
When looking at pictures of the various brands and models, keep in mind that a microscope is made up of many parts that may or may not be from the same factory, or even the same country of origin. Even the high-end brands use some parts made in the same Chinese factory as the low-cost ones, again indicating that such factories can and do produce products and parts of any quality specified by the buyer, to fill the needs of every price-point in the market.
Places to Shop On-line
- Amazon.com — has a large selection of several brands of microscopes, mostly AmScope, Omax, Omano, National Optical, etc., with hundreds of models ranging from toy to lab.
- Microscopeworld.com — they carry several well-respected brands like National Optical, Swift, Motic, and Meiji Techno.
- Microscope.com — their house-brand is called Omano, with many models similar to AmScope and Omax. They also carry Motic and Meiji Techno as their higher-priced brands.
There are other vendors, but the lesser-known ones seem to have slightly higher prices or limited selections. Toptenreviews.com has a list of microscope vendors, and the ones I listed above are in the top three.
Make sure the vendor has at least a 30-day return policy. If you find that the quality and/or features of the one you received does not meet your expectations, do not hesitate to return it and go shopping again. Advertising is often somewhat inflated and unrealistic, and you won’t know until you get your hands and eyes on it. Make sure you keep the receipt and original packing! Even after the warranty expires, the packing (usually molded Styrofoam) will be needed for storage, moving, shipping, and perhaps a sale if you later decide to upgrade.
Parts and Service
Before making any microscope purchase, speak to the vendor and see if they provide warranty service, replacement parts, and service manuals. Many of the far-east import vendors do not, making their products inexpensive, but also throw-away consumer products. While replacing the standard-size lenses is easy, obtaining a replacement LED module or power supply module may be unlikely, as such parts change with every new model, and discontinued models are not supported for long, if at all. After that, you have to either start over, or improvise.
Please remember that I’m just one guy with my opinions, and certainly not an expert in the microscope industry. I hope the above will get you started, but please do your own research and carefully consider your purchase.
Next, we’ll take a look at a sampling of accessories and supplies one needs for a home hobby biological microscopy lab.