Microscope Types & Principles
Magnified Observation and Instruments
A microscope is an optical instrument used to view small objects by enlarging them with two convex lenses. Optical microscopes, used for research, illuminate samples with visible or ultraviolet light. Depending on its structure, a biological microscope is categorized as an upright or inverted with a magnification ranging from 10x to 1500x.
Different types of microscopes are used based on the desired level of magnification. Magnifying glasses or loupes are used for quick inspection with a low magnification; binocular microscopes are used to observe from 10x to 50x, and upright/inverted microscopes are used to observe from 50x to 1500x.
Viewable objects by magnification
|1x||Naked eye||Hair (approx. 0.1 mm)|
|Approx. 2x to 5x||Magnifying glass||Plant or insect|
|Approx. 10x to 20x||Stereoscopic microscope||Water fleas and other microorganisms|
|Approx. 50x||Upright/inverted microscope||Insect's compound eye|
|Approx. 100x||Upright/inverted microscope||Paramecium|
|Approx. 200x||Upright/inverted microscope||Pollen|
|Approx. 400x||Upright/inverted microscope||Euglena|
|Approx. 800x to 1,500x||Upright/inverted microscope||Cell or chromosome
|Approx. 2,000x to 1,000,000x||Electron microscope||Objects from 1μm to 0.1 nm such as a DNA (2 nm)|
Trivia: What is the reference for a magnification of 1x?
A magnification of 1x is based on the point where a nearby object can clearly be observed by the human eye. Because this distance is 250 mm (distance of distinct vision), the size that can be observed at this distance is specified as 1x.