Kaylee
The Microscope
The first microscope was invented in the 1590's when Zacharias Jansen a Dutch spectacle maker was experimenting with spectacle lenses. After aligning several lenses and placing them in a tube they discovered that this magnified a specimen while looking through it. In the late 17th century Anton van Leeuwenhoek invented a microscope with the capability to magnify at 270x, this became known as the first "real" microscope. This microscope allowed him to see bacteria, blood, yest plants, and life in water.
Magnifying Power: A compound microscope has two sets of lenses. The lens you look through is called the ocular. The lens near the specimen being examined is called the objective. The objective lens is one of three or four lenses located on a rotating turret above the stage, and that vary in magnifying power. The lowest power is called the low power objective (LP), and the highest power is the high-power objective (HP). You can determine the magnifying power of the combination of the two Lense by multiplying the magnifying power of the ocular by the magnifying power of the objective that you are using. For example, if the magnifying power of the ocular is 10 (written 10x) and the magnifying power of an objective is 4 (4x), the, magnifying power of that lens combination is 40x. If an object is magnified 40 times, the image you see is 40 times larger than the object would appear if viewed with the unaided eye at a distance of about 25 cm.
Magnification: The magnification, or power, of a lens is usually indicated by whole number followed by an "x". The total magnification of the microscope is obtained by multiplying the eyepiece power times the power of the objective.
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10x - Eyepiece alone
4x - Low power objective alone
10x - Medium power objective alone
40x - High power objective alone
40x - Eyepiece and low objective combined (10x4)
100x -Eyepiece and medium power objective combined ( 10x10)
400x -Eyepiece and high power objective combined (10x40)
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The Calculated total magnification of the following microscopes:
1. A 15x ocular and a 40x objective? 600x
2. A 10x ocular and a 4x objective? 40x
3. A 10x ocular and a 100x objective? 1000x
4. A 15x ocular and a 4x objective? 60x
5. A 10x ocular and a 40x objective? 400x
6. A 15x ocular and a 100x objective? 1500x
Parts of a Microscope
Diaphragm: Controls the amount of light
Objective Lense: magnifies 10x, 40x, 65x.
Stage: This is where you place your slides
Coarse focus knob: use this when using the lowest objective lens (10x)
Arm: 2-point contact to carry
Ocular lens: you look through the eye piece (10x magnification)
Light: provides light source
Base: Bottom of the microscope another place
Fine Focus Knob: focuses the slide on medium or on high makes the slide more clear.
