The Microscope The History Zacharias Jansen The First Microscope The History Video The History Hans and Zacharias Janssen in the 1590s created the first compound microscope Anthony van Leeuwenhoek and Robert Hooke made improvements by working on the lenses Anthony van Leeuwenhoek Robert Hooke Hooke Microscope Simple Compound Stereoscopic Electron Simple Microscope Similar to a magnifying glass and has only one lense. Compound Microscope Lets light pass through an object and then through two or more lenses. Stereoscopic Microscope Gives a three dimensional view of an object. (Examples: insects and leaves) Fruit Fly Electron Microscope Uses a magnetic field to bend beams of electrons; instead of using lenses to bend beams of light. Pollen How a Microscope Works Ocular Lens (Magnifies Image) Objective Lens (Gathers Light, Magnifies And Focuses Image Inside Body Tube) Body Tube (Image Focuses) The Parts of a Microscope Body Tube Nose Piece 3,4,5 are Objective Lenses Stage Clips Diaphragm Light Source Ocular Lens Arm Stage Coarse AdjCoarse Adj. Fine Adjustment Base Skip to Magnification Section Body Tube holds the objective lenses and the ocular lens at the proper distance Diagram Nose Piece holds the objective lenses and can be turned to increase the magnification Diagram Objective Lenses The Objective Lenses increase magnification (usually from 10x to 40x) Diagram Stage Clips hold the slide/specimen in place on the stage. Diagram Diaphragm controls the amount of light on the slide/specimen Turn to let more light in or to make dimmer. Diagram Light Source Projects light upwards through the diaphragm, the specimen and the lenses Diagram Ocular Lens/Eyepiece Magnifies the specimen image Diagram Arm Supports the microscope when carried. Holds the body tube, nose piece and objective lenses Diagram Stage Supports the slide/specimen Diagram Coarse Adjustment Knob Moves the stage up and down (quickly) for focusing your image Diagram Fine Adjustment Knob This knob moves the stage SLIGHTLY to sharpen the image Diagram Base Supports the microscope Diagram Magnification To determine your magnificationyou just multiply the ocular lens by the objective lens Ocular 10x Objective 40x:10 x 40 = 400 Objective Lens have their magnification written on them. Ocular lenses usually magnifies by 10x So the object is 400 times larger Magnification and Orientation Resolution Resolution ( d ) is the degree to which a microscope can distinguish fine details. The number represents the minimum distance that must separate two points for them to be distinguished by the human eye. Field of View and Light Intensity As the magnification increases--- The field of view decreases and the light intensity decreases Using a Microscope Start on the lowest magnification Place slide on stage and lock clips Adjust light source Use course Adjustment to focus specimen Switch to High Power Use fine adjustment to focus Dont use the coarse adjustment knob on high magnificationyoull break the slide!!! Caring for a Microscope Clean only with a soft cloth/tissue Make sure its on a flat surface Dont bang it Carry it with 2 HANDSone on the arm and the other on the base Carry a Microscope Correctly