In the early days of technology, microscopists used to watch specimens under the microscope through natural light or oil lamps. These were the only sources of light for the old yet essential microscopes. Some microscopists created new ideas and used light by reflection or scattering mechanism. Unfortunately, these were not very reliable methods to direct the light on the specimen, and scientists found it tiring to see any object under a microscope clearly.
Modern microscopes, like compound and electron, utilize an advanced and integral light source with a relatively higher intensity. Different microscopes have induced this technology, including optical microscopes. These microscopes are generally divided into simple and compound microscopes, but the latter is primarily used.
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What is a Compound Microscope?
It is a type of optical microscope that typically has two lenses attached to magnify an object. Compound microscopes consist of many essential parts that are all particular in their function. These are widely used in microbiology, medical laboratories, education, or scientific research to understand and enlarge small details in a proper light. A compound microscope generally has structural and optical components that help it function properly.
The optical components of a compound microscope are:
- Objective lens
- A condenser
- Light source
- Collector lens
- Body tube
These components and other mechanical parts help the compound microscope work, allowing an observer to go through tiny details of microscopic or other objects. Let’s mainly discuss the function of the light source.
What does a Light Source do on a Microscope?
The light source is a part of the illuminator in any type of microscope, usually in the base. Most microscopes utilize halogen bulbs or low-voltage lights to illuminate the specimen. A light source can be pre-installed in the equipment, or some researchers use external sources for a better view. A light source illumes the specimen under observation, so the spectator can easily magnify and observe the details. Once the light falls, it passes through the diaphragm and condenser lens to enhance the focus through an objective lens. This entire process is based on reflection as the light reflects through the objective lens and eyepiece to produce an enlarged image.
The person using the microscope can even adjust the intensity of illuminating light, which means that every microscope has adjustable light sources. Changing or adjusting the light source is essential to produce a clear image, as sometimes the specimen can wash out in excessive light. Moreover, most users find it difficult to get a clear picture in too little light.
Other Optical Components
Light sources alone cannot help a person observe tiny objects under a microscope, but other components have equal significance. These are:
Objective lens: These types of microscope lenses are adjusted near the specimen to provide an initial magnification to the set specimen. A compound microscope has a variety of magnifications for the objective lens, such as 4x, 8x, and up to 100x that are switchable.
Eyepiece: It is another lens that is adjusted near the eye of the observer. An eyepiece helps a viewer closely look at and observe the specimen. An eyepiece of a compound microscope typically has a magnification of 10x.
Condenser Lens: It is another adjustable lens located below the stage. A condenser lens focuses the light from the light source onto the specimen. A user can control the amount and direction of light entering the sample.
Collector Lens: The primary function of a collector lens is to gather light rays from the source and directly focus it on the condenser to help magnify the object.
Body Tube: This part functions to connect both lenses, objective and eyepiece, while the light passes through the specimen. A body tube is a long and cylindrical part of the microscope.
In general, like other microscopes, a compound microscope has numerous uses through different components attached to magnify an object. The light source is one such essential element of illumination in a microscope. This adjustable feature allows the users to control the intensity and direction of light entering the specimen. Understanding the functions of these optical components is vital to achieving the best output while observing any sample.