Differential interference contrast effect

Another system for examination of low-contrast objects such as living cells is the Nomarski or differential interference contrast system. It is also particularly useful for materials that cannot be stained satisfactorily for other reasons, such as very thin sections that take up too little stain. This system employs polarizing filters and quartz prisms instead of the annular diaphragm and phase plates used in phase contrast. This eliminates the halo effect seen in phase contrast, rendering sharply defined images with good contrast, having a characteristically (pseudo) three-dimensional appearance. It is rather less suited to routine work than phase contrast however, and is considerably more expensive. 

Pseudo-3D-effect lending the image the appearance of three dimensions, comparable to the differential interference contrast method. 

Differential interference contrast (DIC) This gives a better contrast than the phase contrast method. It utilizes a phase difference to improve contrast but the separation and recombination of a light beam into two beams is accomplished by prisms. DIC generates interference colors and the contrast effects indicate the refractive index difference between the particle and the medium. 

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