Beach sand
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There are basically two types of microscopes,
high power and low power. You would use a high power microscope for looking at very tiny things like bacteria, blood cells, life in pond water, cells and insect legs.
The low power microscopes are used to look at larger things like a bee, a fly, fabric weaves, coins, stamps and sand grains.
On the left, sand, placed on black paper is best seen with a low power microscope. Head lice (right) are small but visible and yet are best seen with a high power microscope.
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Head Lice -Yuk !
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High Power Microscopes are Most Popular
- For children, hobbyists and general use, high power microscopes are most popular as one can see the truly "invisible" things like blood cells, amoebas and bacteria
- If you are shopping for a child, DO NOT purchase a plastic toy microscope, They will do nothing but frustrate you and/or your child. Real microscopes, with metal frames and glass optics are what you want but are rarely found in stores. When shopping for children, look for a company that provides slides and support material with the microscope so your child will have some direction in using and enjoying the instrument.
- High power microscopes go up to 1000X and have a light under the specimen. The light on a high power microscope must pass through the specimen for you to see an image. You would not look at a coin with a high power microscope as you would only see a black circle on a white background. For most high power applications, a maximum magnification of 400X is sufficient.
- Purchase a model with a built in light source. Models with mirrors are rarely sold today.
- There are no manufacturers of microscopes in the US today. The best "economy" models are made in China.
Some very good product is now coming from China but be careful as there are also some poorly built instruments. We have looked at many brands and can highly recommend the National Optical brand name. They are based in San Antonio, Texas. Microscope World, one of their dealers, carries their products and provides excellent customer service and technical support.
Recommended high power models.
(click on pictures for larger view)
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For
ages 7-12
The National Optical Model 109-L (about $128)
The
109-L is the most popular model used in elementary schools today. With an all metal frame and glass optics, the 109-L provides crisp clear images at
three powers (40X, 100X and 400X). It is
compact in size (about 12" tall) and has a 110 volt illuminator. Shop for this model here.
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For ages 10 - Adult The National Optical Model 131-CLED (about $212)
Unlike the 109-L above, the 131-CLED is a full sized instrument and measures 14" tall. It is very popular in middle school and high school biology classes. Many adults use this model as well (animal breeders etc.) The 131-CLED has an all metal frame, glass optics and a bright LED light which is cool and will not harm specimens. (Hot lights can kill specimens such as protozoans that may be swimming around on your microscope slide.) It has three powers of 40X, 100X and 400X and provides a bit sharper image than the 109-L. Optional accessories include a hard plastic case and mechanical stage. Shop for this model here. |
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For ages 16 - Adult The Model 138-SPMS (about $342)
Exactly like the 138 above but built to superior performance (SP) standards and with a professional built-in mechanical stage (MS). This is more microscope than you would see in a HS biology class as it has four powers, 40X, 100X, 400X and
1000X. It includes a special focusable Abbe condenser above the light and a much smoother mechanical stage than the bolt on types used on the regular 138.
Shop for this model here. |
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For ages 16 - Adult The Model 157 (about
$555)
There is a big price jump when you go from a monocular to a binocular model. The previous models have one eyepiece. The 157 has
binocular vision and is a true research grade microscope. It has a smooth built in mechanical stage, four powers (going to 1000X), a substage Abbe condenser and a bright 110 volt fluorescent light. A cordless version with an LED light is also available (model 158-LED). Shop for both models here. |
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Adult The Model 163 (from $844)
The 160 series offers more features than the 150 series (shown above) and the 163 is a
trinocular model which means that it provides binocular vision plus a third tube where you can place a camera. Research quality, four powers, halogen lamp with dimmer, coaxial coarse and fine focusing. For the price, this is a very fine instrument. Shop for this model here. |
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Adult Digital Microscopes (From $349)
Digital microscopes are similar to the models above but include a built in camera in the top of the microscope. Using the USB port on your computer, the image is displayed on the screen or captured to a folder on your hard drive. Digital microscopes can be used as regular microscopes, without the computer and come complete with software, cables and calibration slide (for making measurements). Shop for digital microscopes here. |
Low power microscopes
are used for looking at larger things.
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Low power microscopes usually have both a top and bottom light (reflected and transmitted) and are good for looking at transparent objects as well as opaque objects. Specimens include coins, stamps, whole insects, fabric weaves, insect wings, sand, soil and tiny electrical components. Magnifications range from 10X to about 80X.
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Most low power microscopes are called "Stereo" microscopes and have two eyepieces and a separate objective lens for each eyepiece lens. This allows triangulation and provides a "stereo" or 3 dimensional image. When you look through a stereo microscope, the image will have depth.
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Low power or stereo microscopes are usually chosen for a particular application. The most common magnifications used are 20X, 30X and 40X. More magnification is not always better as you see less of the object at the higher powers. A coin collector, for example would want a 10X model and someone who collects sand would want one from 30X-40X.
- There are three general types of stereo microscopes. Those with a single power (we recommend 20X or 30X), those with two separate powers (we recommend 10X / 30X or 15X / 45X) and Zoom models. Zoom
stereo microscopes provide a continuous range of magnifications, from about 10X to 40X.
Recommended low power models.
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So
which microscope should I choose?
It really
depends on your applications. As a gift for children, you will find that
the high power microscope is more useful and has more educational value than the
low power counterpart.
There are many more activities that one can do with a high power microscope and
high power observations are arguably more exciting. We have seen children
spend literally hours examining pond water critters and insect parts with a microscope.
Also, high power microscopes are generally the types used in schools (grades
3-12). If you are looking for other types of microscopes or curious about models other than these basic instruments, go here and see other types.
Now I have a microscope. What do I do with it?
There are many books and online resources available describing educational activities that one can do with a microscope. If you are working with a high power microscope, you should first learn how to properly use it and learn how to prepare wet mount slides. Hopefully the company you purchase your microscope from will provide slides and information. Check out this website for other info and activities. A good place to start would be here. Bookmark or link to us as we are continuously adding new material.
To learn more technical information about evaluating microscopes, read this.
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