The Light Microscope

Learning goals We are learning the parts of a microscope. We are learning to accurately view objects through a microscope.

Microscopes In high school we use light microscopes. They use light to illuminate images. There are other microscopes called electron microscopes which use a beam of electrons. These give amazing views but each cost hundreds of thousands of dollars.

Red Blood Cell Images Light microscope Electron microscope

Using a Microscope What is the field of view? The white circle that we see when we look under a microscope.

Special Parts of a Microscope Ocular Lens: Or the eyepiece lens, it is what the scientist looks through to observe the prepared slide on the stage. Also magnifies the image 10 times the naked eye (10x). Objective Lens: Lens that provides additional magnification. Three types: Low (4x), Medium (10x), High (40x) All three lenses on a revolving nosepiece.

Diaphragm: Controls the amount of light entering the slide. Adjustment Knobs: Provides focus control. Two types: Coarse: Large increases in focus Fine: Smaller increases in focus to clarify image.

The Compound Microscope Ocular Lens High powered objective lens Low powered objective lens Medium powered objective lens Arm Clips Diaphragm Stage Coarse Adjustment Knob Light source Fine Adjustment Knob Base

Calculating Magnification Eg.1: What is the magnification of a sample seen clearly under the medium powered objective lens (10x)? Ocular Lens = Med Obj Lens = Total Magnification = The object is magnified 100x that of the naked eye. 10x 10x x *Take the product of both lenses 100x

Drawing Scientific Drawings Guidelines to following when doing microscope drawings: Circle indicating field of view Title at top of drawing Magnification at bottom of drawing Draw using pencil ONLY Label significant points using a ruler

Learning goals We are learning the parts of a microscope. We are learning to accurately view objects through a microscope.