Imaging Characteristics of the Oil Immersion Objective for Metallographic Microscopes
The imaging principle of a metallographic microscope is based on physical optics. It uses electron beams and electron lenses instead of light beams and optical lenses, and forms images relying on the imaging principle of convex lenses. It employs objective lenses with very high magnification to observe fine structures of specimens.
An important component of the Olympus metallographic microscope is the oil immersion objective. When using a 100× objective lens in the metallographic microscope, light will refract and scatter when passing through media with different refractive indices. Part of the light will be lost, resulting in less light entering the lens barrel, a dark field of view and blurry specimen observation. This occurs because the oil immersion objective of the metallographic microscope has a high magnification but a small lens aperture.
Therefore, a medium with a refractive index similar to that of glass, such as cedar oil, is added between the lens and the slide. More light can enter the microscope oil immersion objective, the brightness of the field of view is improved, and the specimen image becomes clear.
However, it should be noted that the operation of the microscope oil immersion objective differs from other objectives. The focal length of this objective lens should be adjusted before observation with the oil immersion objective.
