optical microscope

microscopy

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June 25, 2026

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An optical microscope is an instrument that uses lenses to magnify small objects, allowing for a closer examination of minute structures. These microscopes utilize light to create enlarged images, and their magnifying power is expressed as a ratio indicating how many times the object appears larger. The resolution of an optical microscope, measured in micrometres, indicates the smallest detail that can be observed.1

Optical microscopes can be simple, with a single lens, or compound, with multiple lenses. Simple microscopes can magnify up to 300 times, while compound microscopes can achieve magnifications of up to 2,000 times and resolve details down to about 0.2 micrometres. Images can be captured through photography, known as photomicrography, with modern digital imaging replacing traditional film. Specialized optical microscopes exist for specific purposes, such as metallographic microscopes used for examining metal surfaces and minerals.123

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microscope
History of optical microscopes
The concept of magnification has long been known. About 1267 English philosopher Roger Bacon wrote in Perspectiva, “[We] may number the smallest particles of dust and sand by reason of the greatness of the angle under which we may see them,” and in…
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The concept of magnification has long been known. About 1267 English philosopher Roger Bacon wrote in Perspectiva, “[We] may number the smallest particles of dust and sand by reason of the greatness of the angle under which we may see them,” and in…
Read More

metallurgy
Optical microscopy
The simplest, and oldest, type of metallography (though hardly a century old) involves polishing the surface to a mirrorlike finish and examining light reflected from it at magnifications of 50 to 1500×. If the surface is lightly etched in an appropriate solution (often…
Read More
The simplest, and oldest, type of metallography (though hardly a century old) involves polishing the surface to a mirrorlike finish and examining light reflected from it at magnifications of 50 to 1500×. If the surface is lightly etched in an appropriate solution (often…
Read More