Calculations with Optical Instruments
Microscope
Calculate magnification, focal length, and tube length of a microscope. A light microscope has two lens systems: the eyepiece at the top, through which you look, and the objective lens at the bottom. The tube is located between them. Focusing, or sharpening, is achieved by changing the distance between the objective lens and the specimen.
Mt = Mob * Mep
The overall magnification of the microscope is therefore the result of the magnification of the objective lens multiplied by the magnification of the eyepiece.
Mob = ltl / fob
In a classic microscope with a finite tube length, the magnification of the objective lens is approximately calculated by dividing the mechanical tube length by the focal length of the objective lens.
Mep = 25 cm / fep
The magnification of the eyepiece and its focal length are in the same relationship as the corresponding values of a magnifying glass, because these two objects essentially act as visual aids that increase the viewing angle. However, an eyepiece is generally more complex in its construction.
A microscope is an optical instrument used to magnify and thus visualize very small objects or structures. Light microscopy is based on the sophisticated use of lenses. These refract light rays, producing a magnified image. Modern microscopes often have various objective lenses with different magnifications, selectable with a revolver. Additionally, illumination systems, condensers, and filters can be used to improve contrast, brightness, and resolution. In many areas of biology, medicine, and materials science, the light microscope is an important tool that enables rapid, often non-destructive, and detailed examinations with relatively little effort.
