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Choosing the Right Microscope
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Helicotyenchus nemotode with distinctive spiral shape at 100x.
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An instrument of exploration for the inquiring child or serious adult hobbyist.
In 1675 a Dutch merchant looked through a small handheld lens of his
own making and discovered living creatures in rainwater which had
stood for a few days in a new pot. Without fully comprehending the
importance of what he had seen, Anton van Leeuwenhoek had invented
the microscope.
Today, a quality introductory microscope, such as the Meade Model
9200, would astonish van Leeuwenhoek with the incredible detail that can be
observed. Examine the crystalline structure of ordinary table salt at 40x or
100x; study features of a leaf's cell structure at 100x or 400x; or follow in
van Leeuwenhoek's path and observe a fascinating array of animal life-forms in
a simple drop of pond water. Applications of the Meade biological
microscopes presented here are almost as limitless as your
imagination.
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All biological microscopes share these basic features and components:
- The Stage: Specimens (i.e., objects to be observed)
placed on a glass slide and ready for observing are
positioned on the microscope's stage, a smooth, flat surface used to
hold the glass slide. On most microscopes the specimen glass
remains fixed while the microscope's objective lens and eyepiece
move as a unit up or down to focus the image.
- Objective Lenses: A microscope's objective lens forms the image that
is observed with the eyepiece. Different objective lens designs
permit different magnifying powers. Each Meade microscope includes
three objective lenses mounted on a rotating turret
for ease in switching powers.
- Eyepiece: The ocular, or eyepiece, consists of a series of lenses
mounted in a barrel and placed in the eyepiece sleeve at the upper end of
the microscope. Eyepieces of varying powers work with objective
lenses of varying powers to yield a range of microscope magnifications.
Diatom at 40x. This salt water organism has a beautiful symetrical shape.
Leaf surface at 40x.
Fresh water diatom at 400x displays it's starshaped structure.
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- Magnification: The effective magnification of a microscope is
determined by multiplying the eyepiece power by the objective lens power. Thus a
40x objective lens used with a 10x eyepiece presents an effective
magnification of 400x to the observer. Lower magnifying powers allow for
brighter, sharper images combined with a wide field of view; higher powers, often
useful in specific observing situations, present larger but dimmer images with
narrower fields of view. When observing a specimen, always begin at lower
powers, progressively increasing to higher magnifications.
- Focusing: All Meade microscope models include a focusing control for
quick focusing of the image. More advanced Meade Models 9400, and
9600 include both coarse and fine focusing controls; the fine focus is
particularly advantageous in high-power applications.
- Light Source: Used to illuminate the specimen, Meade Models 9200
and 9400 include adjustable mirrors to reflect an external light source
into the microscope's specimen observing area; Models 9460 and 9600
utilize built-in light sources to provide direct and intense object
illumination at high powers.
- Condensing Lens: All Meade microscope models include a sub-stage
condensing lens that concentrates light on to the specimen. A rotary
variable-aperture diaphragm permits varying illumination intensities.
Models 9460 and 9600 include more sophisticated Abbe-type
condensing lens systems and built-in color filter holders.
- Prepared Slide Set: Each Meade microscope model is packed with a
complimentary set of five ready-to observe prepared animal and
vegetable slide specimens, plus five blank glass slides for your own
specimens.
- Meade #904 Slide Set: Available from your Meade dealer at modest
cost, The optional Meade #904 Slide Set includes 25 prepared slides of
fascinating biological subjects, all of which are different from the slides
included with the complimentary slide set, above.
Meade biological microscopes are manufactured to
discriminating Meade optical and mechanical standards. Objective and
eyepiece lenses are of optical glass, exclusively, providing images far
sharper and higher in resolution than can be obtained with
less expensive plastic lenses. Mechanical systems, including rotating
turret assemblies, rack-and-pinion focusing mechanisms, and lens
mountings are of machined brass and steel to permit years of quality
performance—performance backed by the world's leading name in
commercial optics, Meade Instruments.
Pollen tetrads of Lilium plant, 100x.
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Leaf stomata at 100k.
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Salt crystals at 40x.
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Ectocarpus algae at 100x.
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