Light microscopes work by employing visible light to detect small objects, making it a useful research tool in the field of biology. Despite the many advantages that are possible with this equipment, many students and teachers are unaware of the full range of features that are possible. Because the cost of the instrument increases with its versatility and quality, the best ones are not usually available to most academic programs. That makes it challenging to provide a well-rounded education to anyone except those who can afford the expense.
Despite the changes in feature availability which are present with light microscopes today, even beginner model can help students to begin seeing the vast array of views that are possible when we start looking inward instead of outward. This instrument can even help teachers to conduct some reasonably sophisticated assignments and experiments without a massive investment in the program.
Many people believe that the key to getting the most out of a microscope is to get a strong enough magnification. There are actually four different challenges that come before this issue: sufficient contrast, finding the focal plane, resolution levels, and recognizing the subject.
If you are getting ready to begin studying in the field of biology, then these are the advantages and disadvantages of light microscopes to review.
List of the Advantages of Light Microscopes
1. Light microscopes are relatively easy to use.
Because the only resource you need to have available with a light microscope is light waves, you can use this equipment almost anywhere to complete your studies. It is also possible to create an artificial environment which provides artificial light in large quantities to make using the microscope possible. You will not need any special aids to operate the equipment unless it malfunctions for some reason. Because of its overall simplicity, almost anyone can afford and use them for their research.
Entry-level models for student studying are about $100 per unit. If you pay about $250, then you will receive a top-of-the-line option that can take you through your student career or provide more teaching opportunities. Upper echelon models are typically priced between $10,000 to $50,000, depending on the exact features that you want.
2. Light microscopes are small and lightweight.
Unlike other microscope designs, the light microscope does not contain anything that is excessive or unnecessary to the structures you wish to view. Entry-level models are some of the lightest and smallest microscopes that you can find in the world today. Because this equipment is exceptionally portable, you can study your findings at almost any location, making it possible to experience instant results.
You won’t receive this advantage if you are trying to use an electron microscope for your work. Some models require an entire room for their operations, which means you need to bring the research to it instead of taking your equipment to where you need to work.
3. Light microscopes offer high levels of observational quality.
When you use this equipment in natural light, then the magnification you receive through the lens will use the spectrum of light waves that you use every day. That process makes it possible to study almost anything in its natural colors thanks to the reflections that occur. You don’t need to worry about any alterations to the color of the cells or the textures of what you are looking at with this unit. That means there are never any questions about the authenticity of what you are seeing because this equipment doesn’t require dyes or visual aids to the same extent as other microscope designs.
If you were to use an electron microscope, then everything you would see would be in black and white. That outcome occurs because electrons do not possess any color since there is no light involved. When a better visual impression is necessary, one must add artificial coloring to the results, which you receive automatically when using a light microscope.
4. Light microscopes are unaffected by electromagnetic fields.
When you are using a light microscope, then the equipment in your hands adapts to changing natural conditions with relative ease. Although darkness and rain are obvious obstacles to the successful use of this item, you will not experience the aberrations that are possible when there are disrupting factors in the environment. Some microscopes will not provide you with accurate results when they are in the presence of a magnetic field. If your work requires that exposure, then this design is your best option.
5. Light microscopes do not require radiation to operate.
If you are using an electron microscope for your research, then the equipment will create a strong beam of high radiation that will kill whatever living objects are in its path as you look at the sample. This issue does not exist when using a light microscope. Although there might be quality issues to consider, especially in low-light conditions, it is also much easier to maintain the overall integrity of each slide with this equipment compared to other operations.
When you work with a premium-quality light microscope, then you can still see many of the critical details that are necessary for the learning process. You will receive details about the cell walls of your sample, bacteria that may be present, and even nuclei details or cellular components to facilitate your progress through the curriculum.
6. Light microscopes require very little training.
You won’t find any microscopes that offer an experience that is comparable to a computer’s plug-and-play design, but a light microscope comes pretty close. Most people can figure out how to use the equipment within a few minutes, even if there aren’t any instruction manuals available to review. That means this equipment is the perfect option for teachers who are teaching an introduction to biology class or specific scientific concepts in this smaller world. You can spend more time on the curriculum because you are spending less time training everyone on how to use each microscope.
7. Light microscopes allow you to observe living organisms.
If you want to observe living microorganisms through a microscope, then a light microscope is your only option. Electron microscopes will kill the organisms because of the radiation they emit. Although this won’t impact your health any, it could impede your studies since there won’t be anything moving around. This process includes bacteria, which is why it is such a beneficial tool in the study of biology.
You won’t be able to observe every structure of some living things because of the natural limitations of light’s wavelengths, but you will get a good sense of what the cellular components of your sample are when using this equipment.
8. Light microscopes come with two common options to use.
There are two different types of light microscopes that are typically used for biology research right now. The first is called a compound microscope, which allows you to have the strongest magnification possible for this equipment option. You must work with specimens which are quite thin and bright for the light to pass through appropriately. Glass slides are mandatory for this unit, which cannot produce a 3-D image even if there are two eye pieces available for the user.
Stereo (dissecting) microscopes provide users with an opportunity to observe larger specimens if they are opaque. They can only magnify up to 70 times with even the top-tier models, but you will receive a panoramic view of what you are studying. The image delivered to each eye is slightly different with this option, which is why the view is beneficial. You don’t need to go through the process of elaborate sample preparation with a dissecting microscope either.
9. Light microscopes have a minor maintenance cost compared to other models.
Not only are light microscopes typically cheaper to purchase, but they are also less expensive to maintain at an operational quality. This advantage applies to both compound and stereo microscopes. The costs may still be too high for some facilities, teachers, or families to afford in some circumstances, but there are more options available with this design compared to any of the different types of electron microscopes that are available today.
If you have a single ocular microscope that you are using, then there is nothing you need to do with the eyepiece except to keep it clean.
10. Light microscopes can use fluorescent lights to display a sample visually.
If you find yourself in a laboratory setting, then you might be able to use a fluorescent light microscope for your work. Although this option is not usually available to the general public, the intensity of light that is available with this option helps to create a longer wavelength that researchers can use for studying. That means you don’t need to use high-intensity light to observe the living sample, which means there is more clarity available with less harm to your research compared to previous evolutions of this technology.
11. Light microscopes are fully adjustable to the comfort level of the user.
This advantage applies directly to the compound or binocular-style light microscopes that are available today. You can adjust the eyepiece on the unit for separation just as you would when looking through a set of binoculars to obtain the clearest view possible of your specimen. Then you can adjust the intensity of the illumination, move the slide if one is present, and adjust your contrast to ensure that you’re viewing something with accuracy.
One or both of the eyepieces on a binocular-style light microscope might offer a telescoping feature as well, allowing you to perfect the focus while working. Since the average person doesn’t have eyes that match perfectly, most will focus on one eyepiece to match the other to create the necessary outcome for study.
List of the Disadvantages of Light Microscopes
1. Light microscopes do not magnify at the same level as other options.
The typical light microscope cannot magnify as closely as an electron microscope when looking at some of the world’s smallest structures. Most models are capped at 2,000 times or thereabouts, with some entry-level models offering significantly less to the user. Because the relatively long wavelength of light decreases the ability of the equipment to magnify in the small focus lens, you may not always see everything that is going on with a slide when choosing this option.
Although some electron microscopes go into magnification factors that are in the millions, you would spend several thousand dollars on the average optical microscope with a 2,000x resolution. You can grab a student electron model for less than $500.
2. Light microscopes have a lower resolution.
The reason why a light microscope has a lower resolution compared to other equipment options is because the refracted light waves are spread out when viewed through the lens. That results in the image that you see being blurry. Even if you can increase the magnification of the unit by adding additional lenses, you will not improve this disadvantage to the point where what you see becomes useful. When you want to view something that is exceptionally small, then you must seek out an alternative microscope.
When you compare this style to an electron microscope, the disadvantage becomes clear when compared to light microscopes. An electron microscope can magnify up to 2 million times, allowing you to visualize structures that are rarely visible when using a form of optical microscopy.
3. Light microscopes make it challenging to view living internal structures.
When you want to view the internal structure of a living thing, then you must use dye to highlight the cells that are present. The only way currently known to science to make this work is to either extract biological elements from the specimen (such as a blood draw or biopsy) or to kill it. Then you must fix it during the dyeing process to ensure that what you can see is an accurate representation of what is on the slide. Following all of these steps will typically eliminate what is usually one of the most significant advantages of using a light microscope for your work or studies.
4. Light microscopes cannot operate in darkness.
The most obvious disadvantage of a light microscope is that you must use it under specific conditions. Although you can add artificial light to the equipment to improve your view, some models do not offer that opportunity. Built-in illuminators are another feature that can be added to the unit if you’re willing to spend enough on the feature. If you don’t have access to any natural or artificial light, then you’re not going to work. It is that simple.
This disadvantage applies to some of the smaller objects that you may wish to study in the world of biology as well. A micrometer, which is often referred to as a “micron,” is one-thousandth of a millimeter. Light microscopes use a white light wave that is the equivalent of 0.55 microns. That means you cannot observe the details of anything smaller than 50% of the wavelength with clarity, which is 0.275 microns.
5. Light microscopes cannot provide three-dimensional renderings.
When you are using a stereo microscope, then you can sometimes see depth in the sample thanks to the fact that you’re receiving two slightly different views of the object you are studying. If you need to see the 3-D external shape of an object with your work, then your best option will always be an electron microscope. You will need to use an SEM (Scanning Electron Microscope) to counter this disadvantage of the light microscope design, so expect to pay about $1 million for an upper-echelon field emission model.
6. Light microscopes require you to have an expectation of what you want to find.
It is challenging to locate something when you have no expectations about what it will look like under the microscope. You will need to consider whether it is moving or not. The item might be stained, pigmented, or filtered with markers, so you must understand what is aiding the color of the slide or object under study. Many students will look through a light microscope for the first time and think that what they are looking at is dirt if the settings are at a low enough magnification level.
When you have an electron microscope (especially a scanning model), then you have an equipment option which can allow you to match the pictures you see with current textbooks, online resources, and other research materials. You do not have that luxury when using a light microscope.
7. Light microscopes can come with very low magnification caps.
It is not unusual for an entry-level microscope to come equipped with a maximum magnification level of just 40x if you purchase one of the models priced under $100. Some models come with a power level as low as 3.5x to help you find the initial specimen that you wish to study, but there are models that do not go up much higher than this. The most frequently used lens when operating a light microscope is 10x, which can give you a final magnification of 100x when used in conjunction with a 10x ocular lens.
Is a Light Microscope the Best Option for Your Studies?
The advantages and disadvantages of a light microscope are taking advantage of an explosion in technological evolution that is occurring in this field. Advanced models that include fluorescent lighting making it possible for researchers to see two different proteins at the same location without requiring dyes that could harm the sample. When using the standard red and green markers, they overlap to form a yellow color that makes it easier than ever before to identify key components.
Although a light microscope does not come with the advanced components of an electron microscope, a compound model is very affordable and easy to use. You can still access more information about the micro-world when studying biology while enjoying an exceptional level of portability. That is why almost everyone’s first microscope ends up being a light microscope.
Natalie Regoli is a child of God, devoted wife, and mother of two boys. She has a Master's Degree in Law from The University of Texas. Natalie has been published in several national journals and has been practicing law for 18 years.