A microscopic lense condenser is one apparatus that sits directly below the stage and contains one or much more lenses. The lenses take it the scattered microscopic lense light source and “convert” the irradiate rays into a neat, converging beam, or a cone of irradiate which light up with the stage aperture and specimen.

You are watching: Function of the condenser on a microscope

The procedure of typical microscopes relies on 2 things. One, the light hitting the specimen correctly. Two, the light entering the target lens correctly. A light source needs come illuminate the specimen in the suitable fashion. The light requirements to refract through and around the specimen in an arranged fashion. How deserve to we focus the irradiate onto the specimen so that the irradiate is organized, and much more light information deserve to be gathered through the target lens?

There room multiple procedures the irradiate goes v to obtain from the light source to the specimen. A halogen irradiate or LED light is a simple enough light source. From this source, we need to make certain the light gets focused onto our specimen i beg your pardon is much smaller 보다 the size of the irradiate source. This is done making use of the condenser.

How does a Condenser Work?

What carry out you notification about exactly how the light that exits the light bulb? that goes in all type of different directions! This is no an excellent if we room trying to focus the light up v the stage aperture.


*

We require a method to focus as much of this irradiate as possible onto the specimen we room interested in. So, let’s collection up a schematic that a light source and ours specimen.

*

We have the right to see that for the many part, irradiate isn’t really hitting the specimen sample (the smiley challenge on a glass slide) in an reliable manner. They are hitting the at various angles and different directions. Once this light passes v the microscope slide and then right into the lens ~ above the other side, it is walking to be unorganized and our photo will be blurry and unresolved. 

This is wherein the condenser comes right into play. The condenser will certainly go in between the light resource and the specimen and also takes the random angles and also “converges them”. The condenses every these various light rays into a solitary point right into an organized cone that light.


*

The light it s okay condensed and also hits the sample in a much more organized fashion. Thus, when the light pipeline the specimen and also goes come the target lens ~ above the other side, the specimen will appear much more clear and vivid once we look in ~ it through our eyes. A condenser is usually two lenses back on cheaper microscope sets there may only be one. The bigger lens help to collect light and kind the light source and one more smaller lens concentrates the light under further. 

There are commonly two controls to aid control the condenser. There is one knob the moves the whole condenser closer or additional from the specimen stage. This helps through fine-tuning the resolution the the picture being seen. The other control is the diaphragm, i beg your pardon controls the lot of light in reality going to the sample. For much more information top top diaphragms check out Diaphragm the a Microscope: What is it and how deserve to it it is in used?

The mechanics the a microscope condenser are summarized below:

Light light ray propagate in arbitrarily directions from the light source.Some of this light end up hitting the condenser lens.The condenser lens “organizes” the light into parallel, or a converging beam.This beam includes “organized” light.This “organized” cone of irradiate is directed up and also refracted through the specimen i beg your pardon is gathered by the objective lens.

Types the Condensers

There are multiple type of condensers the end there to exactly for certain things aberrations or imperfections that are seen through the observer. Together we currently know, the condenser help to focus the light onto the specimen in a much more organized and uniform fashion. Not to acquire too technological – however this focusing procedure can it is in tricky.

Light beam don’t specifically travel in a perfect manner, for this reason engineers and scientists got an innovative in condenser style to account for these imperfections. Over there are usually three species of condensers: The Abbe (original) condenser, Aplanatic condensers, and devoted condensers. 

Abbe Condenser

The Abbe Condenser, named for ernst Abbe who designed it ago in the 1800s, to be the original one. This is basically the condenser we talked around in the above section. 

These are used in simpler and also less high-quality microscopes and are typically the default condenser shipped by the manufacturer. 

These types of condensers carry out not correct because that spherical or chromatic aberrations but can have actually numerical aperture settings, in an ext expensive models, approximately 1.40 number aperture. If you room not certain what number aperture is take it a look in ~ this post.

See more: How Much Was A Candy Bar In 1960 S, What Candies Were Popular In The 1950S


*

Aplanatic and also Achromatic Condensers

These kinds of condensers deal with some errors in how light gets concentrated onto the beam. Ideally, light the enters and exits the condenser lenses leave prefer this:

*

The irradiate beams go into the second lenses mainly parallel to every other and also exit with a convergence on the smiley face. In reality, this happens:

*

The irradiate is every muffled! This is what optical engineers call an aberration. Basically, that is impossible to do a perfect lens because of imperfections of the glass material or exactly how the lens is shaped. So, if friend really need perfect light to get in your sample, you would certainly use among these progressed condensers come account because that these aberrations in her light source.

The instance described over is a spherical aberration. So, there are condensers that assist mitigate these kinds of errors of light propagation. Another form of aberration is referred to as a chromatic aberration

This is slightly more complicated. In the spherical aberration, it seems every light beam takes a contempt “off-path” course from the appropriate case. Fine in chromatic aberrations, every light ray of different wavelength additionally deviates from their right path. 

This is a an outcome of how light diffracts when it enters and exits the lenses. Chromatic aberration-solving condensers improves upon spherical aberration-solving condensers through not only fixing irradiate paths, yet by solving every wavelength’s light path. 


*

Specialized Condensers

The final category is rather broad! There room a ton of specialized applications in microscopes – even if it is you room looking at transparent (see-through) specimens, dark or irradiate specimens, using various kind of light resources (using LED, OLED, or a halogen irradiate source), etc. 

There are different kinds of condensers prefer dark field or phase contrast which assist create images with more contrast, or if you room probing materials that are dark, you need corrections to deal with how irradiate interacts with the sample. For much more information top top phase comparison microscopy view this post. So, there are a ton of condensers gift used, girlfriend just have to research what exactly finest fits what you space trying come accomplish!

Numerical Apertures and Condensers

As alluded to earlier and worth discussing here, condensers room a system of two lenses, and also every lens has actually a numerical aperture (NA) setting that along with other determinants ultimately identify the resolution that the image you will certainly get.

This is where points can get tricky with microscope design – exactly how do you integrate multiple lenses with various numerical apertures? 

Well the cheat is to complement the number aperture. If her objective has actually a numerical aperture that 0.80, then her condenser setting should be set to 0.80 number aperture. There are a lot of various techniques to maximize the objective-condenser combinations. As explained in the post Microscope number Aperture: A Layman’s Explanation, optimizing numerical aperture the lenses is a highly sought-after systems for scientists and engineers. 

Methods like oil immersion are regularly used in condensers to improve their numerical aperture and ultimately the resolution of the image. 

For example, if you space using an oil objective with a number aperture of 1.4 and you are trying to usage a condenser through numerical aperture the 1.4 to match the objective, girlfriend will need to use oil, not only to the objective, yet to the peak condenser lens between the condenser lens and the underneath side of the slide to accomplish the appropriate numerical aperture. If girlfriend don’t apply the oil the highest possible numerical aperture you might get is 1.0. 


*

Takeaways

What we have learned now is the the condenser the a microscope is a collection of lens supplied to control the irradiate hitting the sample. Light leaving the light resource is sporadic and also the condenser help to “organize” and “focus” the light onto the specimen correctly. 

There are committed types the condensers to account because that errors in exactly how light goes through a lens or with concerns related come the contrast of images. Condensers are consisted of of lens, so ultimately the number aperture the the condenser will decide exactly how fine the resolution of the final we see deserve to get. 

Condensers are crucial parts of any type of microscope system, and their connection to the light and also objective lens is the can be fried decider of how well a microscope will function.