| Term | Definition |
| Magnification | The degree to which the image of a specimen is enlarged. |
| Resolution | The ability to distinguish individual features as separate; the ability to see detail. Typically,as magnification increases it increases. |
| Contrast | How well features stand out against the background. Magnification does not affect it. To improve it a biological stain must be used. (Blue idion -plant tissue) |
| Field of view | The area seen when looking through the ocular lens. As magnification increases, it decreases....the circle visible through the lenses. |
| Diameter of field | The measure length of the field view. |
| Depth of focus/field/view | The vertical distance always in focus with a particular objective lens. As magnification increases, it decreases. |
| Working distance | The vertical distance from the specimen to the objective lens when focused. As magnification increases, it decreases. |
| Parfocal | The ability to change magnification and keep the image focused. |
| Parcentral | The ability to change magnification and the image centered in the field of view. |
| Compound Light Microscope (lens & magnification) | Ocular lens or eyepiece (10x)
Scanning objective lens.(4x)
Low power objective lens (10x)
High-def objective lens. (40x)
Oil immersion objective lens (100x) |
| Stereo/dissecting microscope (lens & magnification) | Ocular (1x)
10x objective
20x objective |
| 2 types of microscopy | 1. Electron microscopy
2. Light microscopy |
| 2 types of electronic microscopes | Scanning electron microscope- reflects the beam off the surface of the specimen and is therefore useful for observing surface features.
Transmission electron microscope-
Transmits the electron beam through the specimen and is useful for observing internal |
| Compound Light Microscope | Uses more than one lens...results in inversion....use transmitted light which pass through the specimen...useful in observing internal features. |
| Stereo/dissecting microscope | Uses single length to produce magnified image so inversion doesn't occur....uses reflected light which bounced off the surface of the specimen....useful for observing surface features. |
| Ocular lens (eyepiece) | 10x |
| Viewing head | Hold the ocular lenses |
| Arm | Support upper parts and provides carrying handle. |
| Nose piece | Revolving device that holds objective. |
| Scanning objective len | The shortest...used to scan the whole slide...magnifying power 4x |
| Low-power objective lens | Used to view objects in greater details....magnifying power 10x |
| High-power objective lens | Largest of scanning and low-power lens....used to view greater details ...magnifying power 40x |
| Oil - immersion objective lens | Holds a 95x to 100x lens...used in conjunction with immersion oil to view objects with the greatest magnification |
| Stage | Holds & supports microscope slides. Mechanics one is movable |
| Coarse - adjustable knob | Used to bring object into approximate focus;..used only with low powered objective |
| Fine-adjustment knob | Used to bring object into final focus |
| Condenser | Lens system below stage used to focus the beam of light on the object being viewed |
| Diaphragm or diaphragm control lever | Controls the amount of illumination used to view the object. |
| Light source | An attached lamp that directs a beam of light up through the object. |
| Base | The flat surface of the microscope that rests on the table. |
