Photomicrography is a method or process of taking photographs using a microscope. The primary medium for photomicrography was film until the past decade when improvements in electronic cameras and computer technology made digital imaging cheaper and easier to use than conventional photography. Visible light represents only a small portion of the entire electromagnetic spectrum of radiation that extends from high-frequency gamma rays through X-rays, ultraviolet light, infrared radiation and microwaves to very low frequency long-wavelength radio waves. The complex phenomenon of visible light is classically discussed in terms of rays and wave fronts. Beginning with the nature of electromagnetic radiation, including refraction, reflection, diffraction, interference, birefringence, polarization, primary colors, human vision, mirrors, prisms, beam-splitters, laser systems, geometrical optics, filtration, color temperature, and the speed of light. Microscopes have been omnipresent in the scientific process for four centuries. The main concept is to make use of lenses to bend light or some other waves so that an image is magnified. Nevertheless, contemporary microscopes have been invented, which sense a surface and map what they feel. These are called scanning probe microscopes.

The two common operating modes for microscopy are transmission and reflection. In transmission it is the light that passes through the specimen, which is monitored. In reflection, the light that bounces off the specimen is examined. There are specialized microscopy techniques such as Hoffman modulation, contrast enhancement techniques and oblique illumination, as well as fluorescence microscopy, differential interference contrast, phase contrast and other important optical techniques used in microscopy. Dramatic increase in the ability to enhance features, extract information, or modify the image resulted from digitization of a video or electronic image captured through an optical microscope. When compared to the conventional mechanism of image capture photomicrography on film, digital imaging and post-acquisition processing enable a reversible, basically noise-free modification of the image as a structured matrix of integers rather than a sequence of analog variations in intensity and color. Many of the basic concepts in optical microscopy can be distilled into a few rules and formulas.

Reviews of the important elements and equations are necessary for an understanding of concepts such as resolution, field of view, numerical aperture, image brightness, useful magnification range, and depth of field. In view of the broad variety of accessories presently available for stereomicroscope systems, this class of instruments is exceedingly useful in a multitude of applications. Stands and illuminating bases for a selection of contrast enhancement techniques are available from all of the manufacturers, and can be modified to virtually any working situation. There are ample choices of objectives and eyepieces, enhanced with attachment lenses and coaxial illuminators that are fitted to the microscope as an intermediate tube. Working distances can range from 3-5 centimeters to as much as 20 centimeters in some models, allowing for a considerable amount of working room between the objective and specimen. The virtual microscope techniques include differential interference contrast, fluorescence, Rheinberg illumination, and polarized light. Martin L. Scott, a noted author and microscopist observes current advances in the microscope optical train, including infinity-corrected optical systems and new design motifs for modern objectives.