Friday, July 13, 2012

Choosing a Children's Microscope

Choosing the right type of microscope for your child can be somewhat daunting. There are multiple types of microscopes and different microscopes are used for different applications. Here are a few things to consider when looking to purchase a kids microscope.

What type of microscope should I buy?

First you must answer the question: What types of things do I want to examine under my microscope? If you would like to look at samples such as leaves, coins, rocks and objects that you can hold in your hand but would like to view a bit more detail - a dissecting microscope (also known as a stereo microscope) will be perfect for your needs.

The Swift SM102 dual power stereo microscope.

Stereo microscopes will usually have a light above and below the stage. Each light is independent of the other. You might use the light beneath the stage to look at a leaf or a butterfly wing. The light above the stage would be better for viewing rocks or coins.

Stereo microscopes come in two varieties:
  1. Single or dual magnification stereo microscopes - these microscopes allow you to switch back and forth between only one or two magnifications. They are typically less expensive than stereo zoom microscopes.
  2. Zoom magnification stereo microscopes - these microscopes provide a zoom range, for example from 10x-30x magnification. You would be able to see all magnifications within this zoom range. Using the example above, you would be able to view 10x, 11x, 12x, all the way up to 30x magnification.
A dissecting or stereo microscope also provides more working room under the microscope. The microscope is similar to a giant magnifying glass and you are able to put larger objects such as a big bug or rock under the microscope and still be able to focus the image.

The MW1-HB3 cordless student light microscope.
A light microscope or compound microscope is used for viewing biological specimens. The light is located beneath the stage, and the flat specimen placed on the stage (usually between a glass microscope slide with a cover slip) will need to allow light to pass through it in order to view a clear image. Because the light shines through the sample, it must be sliced very thinly, and be quite small. The microscope does not provide room for anything much larger than a microscope slide to fit on the stage beneath the objective lens.

Light microscopes are sometimes referred to as compound microscopes because they have more than one lens. A magnifying lens is a type of simple microscope. Compound microscopes have two lenses (an eyepiece and an objective lens) that are arranged so the light has to pass through both lenses before it reaches your eye.

A light microscope will typically provide 40x, 100x and 400x magnification. Some will provide 1000x magnification. These magnifications are a combination of the microscope eyepiece (10x) and objective lenses (4x, 10x, 40x and 100x).

Light Microscope Options:
  1. Corded light microscopes must be plugged into the wall in order to turn the light on.
  2. Cordless light microscopes run on either rechargeable or disposable batteries. These are best for use out in the field, in a barn, or if children will be walking between a table and the outlet and risk tripping on the cord and knocking the microscope off the table.
  3. Mirrored light microscopes are more rare since the invention of battery operated microscopes. They are often trickier to use, as the mirror must be positioned properly in order to allow light to shine up through the stage.

Images Captured with Stereo Microscopes vs. Compound Light Microscopes

The images below give you an idea of the types of things you might see with either a stereo dissecting microscope or a compound light microscope.

Diatom captured with a compound light microscope.
Leaf captured with a stereo dissecting microscope.
Sugar captured at 40x magnification with a stereo dissecting microscope.
Human blood cells captured at 400x magnification.

If you have any questions about selecting a student microscope, please don't hesitate to give us a call at 800-942-0528, or send an email, Microscope World is happy to help.