How To Buy A Microscope
Following are articles that will help you understand microscope world better:
How To Buy A Microscope
We, at OpticsPlanet.com, believe everyone should own a decent microscope. The fact you are even looking at this Web site indicates you may be considering such a purchase. We assume you want good quality at a good price. That is what we strive to provide. If you are seeking a "cheap" microscope, read our Five Rules. We hope we will change your perspective.
We guide you in making a satisfying microscope selection. We offer suggestions regarding specific models suitable for different levels of exploration and work. We also include a Glossary of more than 200 terms applying to microscopes and telescopes that may be helpful.
In the following pages you will find:
Why buy a Microscope?
A professional microscope is a tool to aid the pursuit of knowledge and an absolute necessity in many medical, scientific, agricultural and industrial careers. Children are encouraged to investigate and may turn to science careers. Others increase their understanding of the "worlds within worlds". Through the microscope, ordinary becomes extraordinary!
Microscopy is usually an indoor experience. When the weather is too hot, too cold, too rainy, or the streets too dangerous, it can always be dry and 68-72° right next to your microscope. Many OpticsPlanet Multiscopes will accept an automobile lighter socket adapter to power their 12v, 20w halogen illuminators. This makes the Multiscope, the world's finest, full-sized, electric field microscope!
Rule 1 Don't waste your money on junk!
Good microscope equipment just will not wear out in normal use. It provides a very satisfying educational experience for any user - child, science student or adult professional. The optics are of professional quality, the mechanical components operate smoothly and accurately, and the owner knows by its excellent performance that this instrument is not a toy. LOMO optics installs professional quality on every microscope we sell.
Rule 2 - Never buy a microscope at a chain store, in a mall, or in a toy store!
With extremely rare exceptions, mall stores just do not carry quality microscope equipment, nor do chain stores or toy stores. Emphasis is on impulse sales and promotions with little regard for quality or longevity. Science specialty stores and instrument dealers are local sources of decent microscopes, but use caution! While the "high-end" microscopes may be terrific, many dealers carry inferior "private label" microscopes that may be cosmetically appealing but are lamentably poor performers. Usually, there is no parts inventory. Should these scopes require repair for any reason, they must go to the recycler instead of the repair shop. There are many Asian microscope manufacturers, but very few produce quality microscopes, and only respected, knowledgeable wholesale buyers obtain those. The junk microscopes and the good microscopes are nearly identical in appearance. They can briefly fool an expert!
Rule 3 - Buy a microscope manufactured by a company that makes professional optics.
Toy companies simply do not turn out good, durable microscopes. Cheesy plastic lenses, plastic gears, absence of good focus mechanisms and poor illuminators add up to a disappointment for everyone but recipient of the cash paid.
Rule 4 - Buy a microscope from a company that will not compromise quality on inexpensive instruments.
OpticsPlanet.com carries a full line of instruments. Even the inexpensive LOMO™ microscopes are of high technical quality. The expense is saved by using time-proven designs - not by making frequent model changes requiring constant new tooling costs.
A professional optics company with a design department staffed by optical physicists and optical designers is the right kind of company to make your microscope - if the company applies its high standards to the less expensive microscopes it manufactures.
Rule 5 - Select a microscope manufacturer that offers a "Limited Lifetime Warranty" and carries the parts inventory to back up the warranty.
Proven designs, good materials and precision machining assure that a microscope has "the right stuff" to last a lifetime. Nothing gives stronger testimony to manufacturers confidence in the products than a Limited Lifetime Warranty against defects in materials or manufacture. Some very good optical companies have made sad compromises on less expensive microscopes and will not provide parts support for microscopes more than seven years old.
Select the right microscope for the age and experience of the user.
Remember the cheap fishing rods and reels that chain stores would promote for children? Not only were they difficult to use, but the line would tangle and the reels would even fall apart! Thoughtful parents buy well designed "good stuff" that is not too complicated for their child to use and is ruggedly constructed of good materials. If children can master the complexities of computers, they can certainly learn to use a microscope.
Younger children will not benefit from the more demanding oil immersion technique required to magnify 1000x. They may also find a monocular easier to handle than a binocular microscope. Choose a compound monocular microscope with 4x, 10x, 40x objectives. With the 1.5x magnification added by the binocular head, this instrument will deliver 60x, 150x and 600x magnification or, select the SF-100™ Stereo Microscope. This will enable them to look at large specimens from 3.3x to 108x in 3-D! See what is included in this great package.
You know your child better than anyone does. Responsible teenage children can learn to use any instrument within your budget that is suited for an adult. They can learn oil immersion technique and the extra cleaning protocols that they must observe with regular use of oil on specimens. Their science teachers will encourage them in their quest for knowledge and give excellent "how-to" advice when asked.
Any LOMO microscope is capable of giving professional results. Refer to paragraphs on Stereo Microscopes and Compound Microscopes to determine which is right for you. If the answer is a compound microscope, there are many options listed in Microscopes.
LOMO™ modular microscopes start with simple, but excellent, student microscopes that the user may upgrade at a later time. They are suitable for advanced college level science majors, doctors' offices and specialized scientific use. LOMO™ also manufactures the LABOROSCOPE™, a remarkably rugged, optically excellent microscope with a full line of available accessories. If you do not find the special equipment you need on OpticsPlanet.com, please email us with your needs at CustomeCare@OpticsPlanet.com.
What Can I see?
The first discovery is that just about everything that is alive or was alive really consists of smaller components called cells. "Simple" specimens take on an elegant complexity when viewed at the cellular level. A whole new universe of incredible beauty and shocking drama becomes visible through microscope lenses. Violence of the "cell eat cell" drama that exists in a drop of pond water can occupy an observer's attention for hours.
With great magnification, we can observe life processes, see the cellular structure of our own blood, common bread mold, yeast that cause fermentation in beer and wine and cause bread to rise. Experts can identify the bacteria that makes us ill - and those that cause tooth decay, gum disease and plant diseases.
With special three-dimensional "stereo" microscopes we see how tiny multi-celled creatures move, the digestive tract of a worm, a fly's eye, or examine fine engraving, collectors stamps, coins and jewelry.
What is a Microscope and How Does it Work?
A microscope is an instrument that magnifies, or makes objects appear larger in order to show detail that we cannot see with the unaided eye. Our own eyes cannot clearly see objects that are much closer than 12 inches. Microscopes solve that problem with curved lenses that bend light and allow us to examine objects and see cellular structure. At highest magnifications, the objective lens gets so close to the specimen it appears to be touching. The microscope eyepiece then compounds the magnification and projects the image on our eye.
How do I know what kind of microscope to select?
Different types of microscope magnify specific sizes and types of specimens. Select the type of microscope that will adequately magnify and also resolve the detail in the specimen you want to examine.
Can I take pictures through a microscope?
Saving microscope images has never been easier. Certain microscopes include trinocular heads (or bodies) or convenient optical tubes onto which the user may attach a video, digital, or photographic camera. Many viewers at one time can then share the image on a large-screen monitor, or the user can preserve the images on videotape cassettes, compact disks, or save them as digital computer files
Do you plan to use film, digital or video cameras with the microscope? Adapters will fit commercial video, digital and single lens reflex cameras to microscopes. Most consumer video and digital cameras will not easily adapt to microscopes. Only digital and video cameras using interchangeable lenses and through-the-lens viewing are well suited for videomicrography or photomicrography. LOMO™ modular Multiscopes, LOMO™ Laboroscopes and the SF-100 stereo microscope are all available with special camera adapters.
What is Magnification?
Magnification -- the microscopes defining trait -- is also the most misunderstood. Usually stated in diameters, magnification is the mathematical product of multiplying the power of the ocular, or eyepiece, times the power of the objective, the lens closest to the object being examined. Microscopes with 10x eyepieces and three objectives of 4x, 10x and 40x, yield 40x, 100x, and 400x magnification, respectively. If a specimen has a true diameter of 1.0mm, at 40x magnification, the detail will appear as if it were 40mm in diameter. Multiscope™ binocular bodies incorporate a 1.5x field-flattening magnifier that adds 50% magnification to the objectives. The three objectives above would magnify 60x, 150x and 600x in a binocular Multiscope™ with 10x eyepieces.
What is "Resolution?
Resolution separates a microscope from a magnifier. Resolution the ability to discriminate between two close objects to distinguish detail. As The higher the Resolution, the closer two tiny points may be to one another and still be distinguished as two tiny points. Magnification without resolution simply enlarges. Without the ability to discriminate more detail, it becomes empty magnification. Two close points will appear as one blurry blob when enlargement exceeds the capability of resolution. Theoretically limited by the interaction of glass and light, true resolution varies according to the quality and design of the equipment and the skill of the user.
What is Parcentered?
Most microscopes have multiple objectives on a rotating nosepiece. As the user turns the nosepiece to bring another objective over the specimen, each image should be right in the center of the view through the oculars, with no change from one objective to another.
What is Parfocal?
As in the paragraph above, the user focuses on a specimen and decides to try a different magnification. When rotating a new objective into position, there should be only minor adjustment to bring the specimen into the same sharp focus as the previous magnification. This is parfocality. (See DIN in Glossary).
How Much Should I Spend?
A good microscope will last a lifetime and therefore is a better value than a poor microscope that has a short life. If you can afford to spend $600, you can own an excellent binocular compound microscope that will compete in many ways with microscopes costing three to five times as much. If you are a medical professional or serious researcher, we recommend the LABOROSCOPE, various models of which range between $2,200 and $3,500. LABOROSCOPES are optically superb, very rugged, high performance instruments that should satisfy any professional.
Is it safe to buy a microscope made in Russia?
Yes, when the licensed factory distributor is based in Northbrook, Illinois, (near Chicago). LOMO America stands behind the factory warranty with service and parts inventory centrally located in the United States.
All other major microscope companies base their manufacture in Japan, Germany or China. Those with warranties depend on U.S. -- based warranty service.
LOMO America provides the strongest warranty in the industry, a Limited Lifetime Warranty, for most of its products.
LOMO PLC is the worlds fourth largest optical instrument manufacturer. Nearly all scientific microscopes used in Russia and the associated republics are manufactured by LOMO PLC. Although LOMO PLC has modified them to suit U.S. voltage requirements and consumer preferences, they employ the same instrument components and optics that have accounted for a huge number of scientific breakthroughs by some of the worlds most capable researchers.
LOMO optics easily surpass most competitive optics selling for twice the price.
We separate light microscopes into two basic classes, Dissecting (Stereo) microscopes, and Compound Microscopes. There are two major distinctions between the two.
1. You will view your specimen in three dimensions with a stereo microscope, not so with compound microscopes.
2. Compound microscopes have enormous magnification range from 10x to 1,500x, compared to practical limitations of 5x to 200x with stereo microscopes. Compound microscopes can reveal detail at the cellular level.
3-D Observation/Larger Specimens
Nothing beats seeing a specimen in 3-D! If you are working with larger specimens, or if you wish to use a microscope to inspect parts, plants, stamps, coins, insects, rocks, fossils or archaeological specimens, or to guide you during fine dissection, you need a stereo or dissecting microscope.
Stereo microscopes have the unique ability to see the third dimension depth. This makes stereo microscopes the instruments of choice for surgeons, gemologists, electronic assemblers, denture makers and fine engravers, to name a few examples. Because two optical systems are joined on one frame, similar to binoculars, stereo microscopes must be perfectly collimated by the manufacturer, otherwise their use can be uncomfortable.
Stereo microscopes have long working distance objectives to enable larger specimens to be examined.
How Stereo Microscopes Give a 3-D Image
The binocular viewer alone does not make a stereo microscope capable of 3-D. Each eyepiece must capture a separate image from its own magnifying lens, known as an objective. The paired objectives work together to show slightly different views of an object to obtain a three-dimensional image, the same way human eyes work together to obtain depth perception. The eyepiece multiplies, or compounds, the objective magnification in the stereo microscope in the same manner as it does in the compound microscope.
Magnification and Stereo Microscopes
For technical reasons, the magnification capabilities of standard stereo microscopes are usually limited to much less than 200x usually 10x-40x. Our SF-100 offers 3.3x 108x.
Field of View and Stereo Microscopes
They may cover a field of view almost as large as a quarter, or as small as a mustard seed.
Illumination and Stereo Microscopes
Dissecting microscope illuminator design commonly provides for incident light -- light falling on the specimen -- and transillumination light passing through the specimen from a light source inside the base. The SF-100 adjustable illuminator may switch between incident illumination and transillumination.
Special (optional) fiber optic illuminators offer very even incident illumination, and others provide very specific spot illumination. Although difficult to believe, the SF-100 package offers up to seven eyepieces and a multitude of magnification choices from 3.3x to 108x!
Compound Microscopes/Smaller Specimens
This is the microscope preferred by medical laboratory technologists examining blood and urine, pathologists screening tissue specimens and smears for cancer cells and microbiologists identifying bacteria in cultures (see Multiscope and Laboroscope models). If you are interested in examining biological specimens at the cellular level, you require a compound microscope. Compound microscopes take their name from the calculation of magnification by compounding the power of the eyepiece x the power of the objective to get total magnification.
How Compound Microscopes Work, the one-paragraph explanation
We have to start at the bottom, to describe properly how a compound microscope really works. Except for some applications in which light shines on the specimen from above, most compound microscopes use transillumination light projected from below to pass through the specimen to the magnifying objective lens. The magnified image of the specimen projects through the draw-tube to the eyepiece where it is magnified another 10x. The eyepiece sends the image to our eyes where the lens projects it on our retina. It is just like a 35mm slide in a projector, or a movie projector at the cinema.
How Compound Microscopes Work, a Little More Detail
1. The illuminator is usually beneath the specimen, which rests on a platform called a stage. Atop the illuminator are lenses that help it transmit a cone of even, brilliant light onto another lens system called the substage condenser.
2. The sub-stage condenser. This device can be raised or lowered by gears to control the point of focus of the light it has gathered from the illuminator so that it focus sharply on the specimen.
3. The iris diaphragm The condenser is frequently equipped with a light valve called an iris diaphragm. The user may open or close this iris diaphragm to control contrast and sharpness.
4. The objectives Powerful magnifying lenses directly above the specimen. Although a microscope is an optical system dependent on several key components, it is the high dry objective (40x) and the oil immersion (100x) objectives that are essential for much of the microscopes capability to magnify and resolve detail. The careful design and precision shaping of these lenses enable them to focus on the specimen so closely they may practically touch it. Our eyes normally cannot focus closer than 10, but some objectives can sharply focus on the specimen within a distance equal to the thickness of a sheet of writing paper. The 10x low dry and the 4x scanning objective are helpful to locate an area of interest using their larger fields of view. In Multiscope, these two objectives are among the best quality in the entire microscope industry.
5. The nosepiece is a rotating turret that can hold multiple objectives. It must be of great precision to enable each objection to rotate into perfect position centered above the specimen.
6. Rising from the illuminator base is the microscope arm. This structural component holds the platform stage, the focusing mechanism, the drawtube and nosepiece, and at the top, it has a socket into which fits the head or body that holds the viewing optics. The condenser rack-and-pinion is attached below the stage.
7. Focusing mechanisms are usually one of two types. In one variation, the platform stage moves vertically with gears to bring it near or farther from the objective, which remains fixed in place. In the other type, the drawtube is moves vertically with the objective and nosepiece while the stage stays in place.
8. The viewing optics consist of the head and the oculars, or eyepieces. Binocular heads require prisms to divide the image-carrying light rays from the single objective to the two oculars. In most binocular heads, there is a comfort adjustment to bring the two eyepieces in line with distance between the users pupils. This is the interpupillary distance (IPD).
9. The binocular viewer also includes a diopter adjustment. This allows the focusing characteristics of each ocular to match the users own eyes.
Magnification and Compound Microscopes
Typical magnifications of compound microscopes may exceed 1000x. In the medical laboratory, the highest magnification most often used is 400x-500x, although a busy laboratory will frequently examine specimens at 1000x 1,500x.
Field of View and Compound Microscopes
The field of view is tiny as little as 1/5th of millimeter less than 1/100th of an inch at 1000x magnification. About the largest field of you can expect with a compound microscope is 1/5th of an inch at 40x (using a 4x objective and a 10x ocular).
Special Illumination/Imaging Techniques and Compound Microscopes
Aside from typical bright field compound microscopes, there are also dark field, phase contrast, differential interference contrast (DIC), polarization, immunofluorescence, and confocal microscopes, as well as combinations of these. There are also other types with very limited applications. By far, most hobbyists will want bright field microscopes. OpticsPlanet.com can provide all of the above with the exception of confocal.
Special Application Microscopes
If you require a microscope for industrial/research application such as inspection of metal parts, material identification, crystalline structure, forensics, polarization, cell culture, pathology, solid-state circuitry manufacture, inspection or assembly, email us at CustomerCare@opticsplanet.com.