NATS 1575 Chapter Notes - Chapter 7: Eyepiece, Optical Instrument, Microscope
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Chapter 7 // The Microscope
-A microscope is an optical instrument that uses a lens or a combination of lenses to magnify
and resolve the fine details of an object.
-The earliest methods for examining physical evidence relied solely on the microscope.
-The magnified image seen by looking through a lens is known as a virtual image, whereas an
image viewed directly is known as a real image.
-The object to be magnified is placed under the lower lens, called the objective and viewed
through the upper lens, called the eyepiece.
-Various types of microscopes are used to analyze forensic specimens.
The Compound Microscope
-In the basic compound microscope, the object to be magnified is placed under the lower lens
(objective lens) and the magnified image is viewed through the upper lens (eyepiece lens).
-The magnification of the image can be calculated by multiplying the magnifying power of the
objective lens times the magnifying power of the eyepiece lens.
-The microscope is composed of a mechanical system which supports the microscope, and an
optical system which illuminates the object under investigation and passes light through a
series of lens to form an image of the specimen.
-The Mechanical System
-Base: the support.
-Arm: the C-shaped upright structure.
-Stage: the plate on which the specimens are placed.
-Body Tube: the hollow tube on which the objectives and eyepiece lenses are mounted.
-Coarse Adjustment: the knob used to focus the microscope lenses by moving the body