Proper Alignment of the Microscope

Abstract

This chapter presents a few simple guidelines for the best alignment of all those components of the light microscope that can be focused or centered. A better understanding of the function of these components and how their control influences the image has become even more critical for electronic imaging. Although analog or digital image processing can, to a small extent, compensate for poor mechanical and optical alignment, the best end result, free of artifacts, is derived from the best possible optical image. The light microscope, in many of its configurations, is a somewhat complex tool with many adjustable components. Good alignment is essential for good image quality, especially for quantitative studies. The chapter also presents the steps for aligning the microscope for Koehler illumination and benefits of Koehler illumination. With the exceptional sensitivity of electronic detectors, hot spots may occur unless the field diaphragm is closed to the edges of the detector's field. Even, uniform illumination of the specimen is achieved by distributing each source point's energy over the full field. Thus, minimal shading correction is required by the video electronics. Full control over the illumination (condenser) aperture allows for the best compromise between resolution and contrast and for some effect on the depth of field. Key components of every light microscope, such as light source, lamp collector, and infinity space, are also presented in the chapter.