Light microscopes and compound microscopes are often used interchangeably. However, what if we tell you they are not entirely the same?
Light microscopes comprise all microscopes that use a light source to illuminate an object. On the contrary, compound microscopes are used to observe biological and microbiological samples. You may say that all compound microscopes are light microscopes, but all light microscopes are not compound microscopes.
Let’s tell you the differences between light microscopes and compound microscopes in detail.
Table of Contents
Difference Between Light and Compound Microscope
What are Light Microscopes?
A light microscope is any microscope that uses visible light to illuminate the sample and produce an image. Previously, light microscopes used natural light to brighten the specimen. But now, an artificial light source of visible wavelength is used to provide light to the object under observation. It may be a halogen light source or LED illumination. Some microscopes have a transmitted light, while others have an incident light.
Light microscopes can be compound microscopes or stereo microscopes. Both are used to observe samples in science labs, yet their application differs. Here is a brief description of both types of light microscopes.
Types of Light Microscopes
Compound microscopes are also known as biology or microbiology microscopes. They study microorganisms and other biological samples like blood cells. Compound microscopes have a maximum magnification of 2000x. You may observe the structure of tissues and other living cells in compound microscopes compared to electron microscopes. Multiple objective lenses allow you to examine the specimen in varying magnifications.
The other type of light microscope is a stereo microscope. They are also known as dissecting microscopes. Dissecting microscopes also use LED or halogen light sources for illumination, but they are not used to examine germs or other microbes. Instead, they have more common applications in physics and electronics labs to study circuits. They are also often called microscopes for electronics. Their magnification ranges between 10x and 50x. They provide information about the details on the surface of visible objects like coins under examination. Biology students may use stereo microscopes to study insects, leaves, or similar samples.
Applications of Light Microscopes
As mentioned above, light microscopes have applications in almost all fields of science, from biology and microbiology to electronics and geology. They are often used to examine rocks and jewels found in nature or to study details on coins by coin collectors.
What are Compound Microscopes?
Compound microscopes are a type of light microscope that enables the examination of organic material at the tissue level. They provide a magnification of up to 2000x, higher than dissecting microscopes. They use a halogen or LED light source to produce images on the objective lens, which are then picked by the eyepiece.
The light source sheds light on the specimen after passing through the condenser lens. The objective lens examines the object with the help of illuminant light and captures the image. The ocular lens or eyepiece picks the observation and magnifies it further for clarity.
Types of Compound Microscopes
There are various classifications of compound microscopes, the most common being:
- Bright-field Light Microscope
- Dark-Field Light Microscope
- Phase Contrast Light Microscope
- Fluorescence Light Microscope
Bright Field Compound Microscope
Bright-field microscopy is the study of samples under a microscope that produces a dark image on a bright background. The common biological microscopes of various brands and manufacturers in school labs are examples of bright field microscopes. They comprise two lenses used to view animal and plant cells at high resolution. People generally refer to a bright field compound microscope when talking of a compound microscope.
Dark Field Compound Microscope
As the name suggests, the dark field compound microscope produces images on a dark background. It is achieved by placing a darkfield cover underneath the stage. The light passing through this cover enters the objective lens only from the specimen. It is mostly used to examine living cells you do not want to stain like live bacteria. It produces unique imaging by providing the specimen with a hollow cone beam of transmitted light.
The specimen seems illuminated and surrounded by a darker area. Thus, this technique of producing specimen images is called dark field microscopy.
Phase Contrast Compound Microscopes
Phase contrast microscopes enhance the contrast or colorless and transparent images to have a detailed look at cells unclear in bright field or dark field microscopes. It is one of the best techniques to observe the living cells in their natural state without staining or fixing them. That is why most biologists prefer using phase contrast microscopes. You may also have a detailed look at biological processes and record them through a microscope camera such as the AmScope MU1803 18MP.
Phase contrast microscopy is preferred for thinner samples. Using an inverted microscope system provides more working space than upright compound microscopes.
Fluorescence Compound Microscopes
Fluorescent compound microscopes are different from the other types of compound microscopes as they produce fluorescence themselves. A dye molecule such as a fluorochrome is added to the sample, which absorbs light energy and releases the trapped energy in the form of light. The fluorescent microscope provides UV or violet, or blue light to the specimen. The mercury vapor arc lamp in fluorescence microscopes produces a light beam that passes through the exciter filter. The filter emits a specific wavelength of light to the specimen and produces the fluorochrome-labeled image.
While toy microscopes are not exactly a type of microscope, they are different from the above-mentioned biological and research microscopes. Microscopes for children have the same composition as a student microscope. However, they are less in weight and cost. You can get a microscope for less than $100.
Application of Compound Microscopes
Compound microscopes are typically utilized in school labs to examine biological and microbiological samples. They may also be used in research labs to study cells and tissues. Examination of biological tissues enables an understanding of parasitic behaviors.
Similarities Between Light and Compound Microscope
As compound microscopes are also a kind of light microscope, there are many similarities between the two. The working principle of light and compound microscope is apparently the same as they both use a visible wavelength light source. Eventually, their structure is also similar to each other.
Let’s tell you the similarities between light and compound microscopes.
Light and compound microscopes follow the same working principle due to similar construction. The light passes through the specimen after falling onto the condenser lens. The objective lens records the image and sends it to the eyepiece. The eyepiece magnifies the observation for the reader to study conveniently.
Both microscopes use a light source of visible wavelength between 400 nm and 700nm. Mostly the light source is LED bulbs. Yet, some microscopes also use halogen light for the illumination of objects.
The structure of light and compound microscopes is almost the same, with slight exceptions. Both contain an illumination source, condenser lens, objective lenses, eyepieces, coarse focus knob, fine focus knob, neckpiece, headpiece, arm, stage, stage clips, and the base. The specimen is placed on the stage to be magnified by the objective lenses.
While the magnification of the compound microscope is higher than the stereo microscope, it is still significantly less than an electron microscope. Thus, you cannot observe the detailed structure of organelles like ribosomes and mitochondria in depth.
Inability to Observe Viruses
Light microscopes, including compound microscopes, cannot be used to observe viruses or atoms. These entities can only be seen under an electron or scanning electron microscope.
The Bottom Line
Compound microscopes are a type of light microscope that uses the light of visible wavelength to brighten the specimen. Light microscopes also include stereo light microscopes or dissecting microscopes. They could be monoculars, binoculars, or trinocular. Compound microscopes are of four types: dark field microscope, bright field, phase contrast, or fluorescence. These microscopes vary in magnification, but they are not the best choice for viewing viruses and the chemical composition of molecules. AmScope B120C is a popular compound light microscope.