Lab 4 Microscopy
Iris Diaphragm
A part of the condenser that can be opened or closed to allow different amounts of light through the condenser
oil immersion
A technique used to increase the resolution of a microscope by immersing both the objective lens and the specimen in a transparent oil.
Total Magnification
Achieved through the interaction of two lenses: the ocular lens (10X) and the objective lens currently in use. ( multiply the magnification of the ocular lens by the magnification of the objective lens being used) Example: 10x4=40x (400)
Arm
Attaches the head, nosepiece, and base. When transporting the microscope, grip the arm with one hand
Nosepiece
Connects the objective lenses to the head, and rotates to change the objective lenses
Eyepiece
Contains the ocular lenses (dissection)
Working Distance
Distance between bottom of the objective lens to the top of the slide
Field of View
Everything that is visible when you look through the eye piece
(LPD X LPM) / HPM
HPD Formula
Depth of Field
How much of the total thickness of a specimen is in focus between different objectives
Parfocal
If a slide is in clear focus with one objective, when you move to another objective what you are viewing will be in partial (almost clear) focus. compound microscopes are usually this kind because larger adjustments cant be made with higher mag
Mechanical Stage Controls
Knobs used to move the mechanical stage left and right or up and down
Ocular Lenses
Lenses located in the eyepiece; magnify 10x normal size
Condenser
Located under the stage aperture. It's used to focus the light through the slide. focuses light into the form of a cone
course adjustment knob
Moves the mechanical stage up and down in large increments. The only knob that should never be used with the high power or oil immersion objective lenses
Stage Aperture
Opening in the mechanical stage that allows light to pass through the slide
Mechanical Stage
Platform that holds the slide in place
Base
The bottom part of the microscope. When transporting the microscope, place one hand under the base for support
Eyepiece
The part of the microscope rat you look into
Head
The part of the microscope that provides attachments points for the ocular and objective lenses
light source
a light bulb that provides light for viewing the image
Focusing Knobs
adjusts the focus by raising and lowering the body tube (dissection)
Zoom magnification control
changes the magnification (total mag =10x) (dissection)
Body Tube
contains ocular and objective lenses (dissection)
Light Source
dissecting microscopes normally have an external light source but some have mirrors to reflect light from below through a glass stage to back-light the specimens (dissection)
focal distance
distance between the specimen and condencer
HPD
high power diameter of field of view
HPM
high power total magnification
stage
horizontal platform with a hole for light beam. You place the slides on it.
LPD
low power diameter of field of view
LPM
low power total magnification
Oil Immersion Objective Lens
magnification by 100x
Low Power Objective Lens
magnification by 10x
High Power Objective Lens
magnification by 40x
Scanning Objective Lens
magnification by 4x
coarse focus knob
moves stage up and down
inversion
property of microscopes that makes images to appear upside-down and flipped left to-right
higher the condencer.......
smaller and more concentrated cone of light
fine adjustment knob
smaller dial used with any objective lense to fine tune the view. constant scans to bring image into focus
numerical aperture
the ability of a lens to gather light is referred to as its
resolving power
the ability of an optical instrument to show two objects as separate
Stage
the area of the microscope where specimens are placed for examinations (dissection)
dissection microscope
used for looking at larger items Used for magnification while dissecting a specimen.
compound light microscope
uses a light source and compounds the magnification of several lenses best for viewing objects from 1cm to 5μm
