Transmitted light optical microscope

Figure 7.1. Schematic of the components of (a) transmitted light optical microscope and (b) reflected hght optical microscope.

A specialized form of the transmitted-light compound microscope is the inverted microscope (Figure 3), used for objects such as cell cultures, in which the microscope tube and optics are mounted below the specimen, which in turn is illuminated from above. A prism is used to incline the eyepieces at a comfortable viewing angle. Another specialized form is the portable microscope , of which the McArthur instrument is the best known. These allow a compound microscope to be taken out into the field. 

The conventional transmitted-light compound microscope uses a bright-field system, in which the condenser gives a bright, even illumination across the whole of the field of view. This form of illumination, when correctly set up, is ideal for the examination of a wide range of specimens, particularly stained thin sections of biological material. Where there are no natural variations in color or optical density of the... 

Suppose a bulk-crystallized polymer sample is observed in an optical microscope with the sample placed between Polaroid filters oriented at right angles to each other. In the absence of any sample, the light would be attenuated owing to the 90° angle between the vectors describing the light transmitted by the two filters. With a crystalline sample of polymer in place, however, a display like... 

The observations are performed with a Leitz Ortholux polarizing microscope equipped with the ftOpak illuminator, lamps for reflected and transmitted light, immersion objectives, and verniers. Characteristics of the polished thin sections and of the nuclear emulsion plates are observed in transmitted light with the same immersion optics after removing the Berek prism. 

Optical microscopy of resin and plastisols were conducted using transmitted light on a Zeiss Optical Microscope. 

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