Chapter 12 - PHOTOGRAPHIC AND DIGITAL PRINTING

Abstract

This chapter presents some modifications that electron micrographs may undergo as a result of different treatments during the photographic printing procedure. Considerable variations in the appearance of an electron micrograph are imposed by the choice of photographic paper, particularly by its grade. A print with adequate contrast should span essentially the entire black and white scale. Although micrographs on hard paper usually appear sharp and contrasty and seem to have much information, fine details are often hidden in the very light or very dark regions, for example, the mitochondrial granules to the right. For routine purposes, micrographs on the soft side are generally preferred because they allow the detection of all objects in the image. The processing may differ for electron micrographs that are used for visual analysis, for measurements, or for publication. The processing will also be different for negatives with a high and a low inherent contrast and for negatives with a wealth of fine details, or for those with only a few grades of density. Even excellent electron micrographs will lose much of their information by inadequate photographic processing, whereas electron micrographs of suboptimal quality may turn out to be useful if skillfully treated.