The Microscope
Stage
clamps hold the slide in place on the stage, and knobs move the stage in either direction
Condenser
directs light from the illuminator through the specimen to be examined
Illuminator
light source located below the condenser provides light for viewing the specimen
Ocular lens
magnifies the image formed by the objective lens. a monocular microscope has only one ocular lens, while a binocular microscope has two ocular lenses. the total magnification of the instrument is the product of the power of the two lenses. thus with a 10X eyepiece and a 10X (low power) objective lens, the total magnification would be 100X, the high power lens would be 400X, and the oil immersion lens would be 1000X. the ocular lens range commonly in power of magnification from 5X to as high as 20X. msot microscopes are equipped with a 10X eyepiece, the best all-purpose size.
Parfocal
object focused using one of the lenses will remain in focus at all other magnifications
Resolution/resolving power
refers to the ability of a microscope to reveal find detail
Diaphragm
regulates the amount of light reaching the specimen. low power requires less light, so it is desirable to lower the condenser and/or partially close the iris diaphragm when the low power objectives are employed. high power and oil immersions objectives require greater illumination.
objective lenses
the primary lenses that magnify the specimen. in the compound microscope these lenses are mounted on a revolving nosepiece that include three objective lenses, low power, high power, and oil immersion. each lens is marked with the magnification. the low power lens is usually marked 10X, which refers to an initial magnification of 10 times. similarily, the high-dry lens is usually marked 40X and the oil immersion objective lens 100X
Refractive index
the refractive index of glass and oil is similar (light does not change speed between glass and oil) so it is not refracted. this is why we use oil immersion and high magnifications
Coarse and fine adjustment knobs
utilized for raising and lowering the body tube. the coarse adjustment is used to bring the object into approximate focus using the 10X objective lens and the fine adjustment is the employed for precise focusing with higher power lenses