ABSTRACT
The resolving power of a diffraction-limited microscope objective is determined by the diameter of the diffraction image of a point source. A series of objectives is frequently designed so that the exit pupil has a nearly constant value of approximately 6.4 mm. In order to obtain diffraction-limited resolution, it is very important to obtain a high level of correction of the chromatic aberration in microscope objectives. For microscope objectives with large magnifications, the magnification chromatic aberration is difficult to correct, although the remaining aberration is not very large. There are many types of microscope objectives, whose design depends on the desired magnification. The chapter describes some of the most common types. Sometimes low-power objectives have an extra single thick meniscus element to reduce the Petzval curvature.
