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Bright-Field Microscope Principle and Working with Image

A bright field microscope is a type of optical microscope that uses transmitted light to illuminate a sample, which is then observed through the microscope’s eyepieces.

Definition of Bright Field Microscope

With a bright field microscope, the specimen blends into the background and appears black. The bright-field microscope, sometimes called a compound or light microscope, is a standard instrument in most scientific research facilities.

A bright field compound microscope is used to examine stained, fixed, and living specimens. The components of a bright-field microscope are the eyepiece, objective lens, condenser lens, stage, and light source, all of which are used to gather electromagnetic radiation in the visible range.

Working of Bright Field Microscope

On the stage of a bright field microscope, the specimen is placed for examination. Light from the source will pass through the specimen and into the objective lens, where a magnified image of the specimen will be formed. The light will then pass through an oracular lens or eyepiece, which will further magnify the image before it enters the user’s eyes. They see a dark image against a bright background.

In a bright field light microscope, only scattered light can get through the objective lens. Unscattered light rays, or transmitted light, can’t get through, so the viewer sees a dark image against the bright field.

LightPath of Bright Field Microscope

Light in a typical bright field microscope is directed from the light source, through the condenser, the specimen, the objective lens, and finally the eyepiece. So, light gets through the specimen and shines on the background, making the specimen stand out. Because natural pigmentation or stains absorb light unevenly, or because they are just thick enough (but not too thick) to absorb a substantial quantity of light despite being colorless, the spectator can perceive objects in the light path.

LightPath of Bright Field Microscope

Figure 1: LightPath of Bright Field Microscope.

Parts of the Bright Field Microscope

 The typical upright compound microscope consists of the following (Figure 1: Bright Field Microscope Image) parts

bright field microscope image

Figure 2: Bright Field Microscope Image

The Base: The base is the part of the microscope that rests on the ground. The U-shaped best describes the layout of this structure.

The Pillar: A pillar is a stand that is placed on the stage and has an orientation that is perpendicular to the stage in bright field compound microscope.

Metal Arm: The curved support known as the arm or metal arm controls and transports the bright field light microscope.

Objective lenses: The image of the specimen is magnified by the objective lenses, which are situated towards the microscope’s base.

Eyepieces: The microscope’s eyepieces are the lenses at the instrument’s top that are used to increase the magnification of the picture.

Stage: This is the platform where the sample goes. Most of the time, it can be changed so that the specimen can be moved to get the image in focus.

Condenser: This is a lens that is placed under the bright field light microscope stage and focuses light on the specimen.

Diaphragm: This is an opening that can be changed to control how much light gets through to the specimen in bright field light microscope.

Illumination system: Illumination system in bright field compound microscope is where the light comes from that is used to light up the specimen.

Fine focus knob: This Fine focus knob is used to make small changes to the bright field light microscope‘s focus.

Coarse focus knob: This is a knob used to make small changes to the microscope’s focus, Figure 2: bright field microscope image.

Nosepiece: This part of the bright field light microscope is where the objective lenses are kept. It can usually be turned, which makes it easy for the user to switch between different objective lenses.

Bright Field Microscope Magnification

Together, the objective lenses and the eyepieces of a bright field microscope establish the bright field microscope magnification. The objective lenses have a predetermined magnification that is typically labelled on the lens. Eyepiece magnification can usually be adjusted and is usually shown on the eyepiece itself. You can use the following formula to figure out how powerful a bright field light microscope is:

Total magnification = Objective lens magnification x Eyepiece magnification

If a bright field light microscope has a 10x objective lens and a 20x eyepiece, for example, the total magnification is 200x (10 x 20).

Application of Bright Field Microscope

Uses of bright field light microscope are often used in biology, medicine, materials science, and quality control, among other fields. Some of the most common ways to use a bright field light microscope are:

  1. Seeing and identifying cells, tissues, and other parts of living things.
  2. Checking for problems in semiconductors and other electronic parts.
  3. Analyzing samples for research and quality control, like in the food or drug industries.
  4. In science education, teaching and showing how to use a microscope is important.
  5. Analyzing forensic evidence, such as fibers, hairs, and other traces.
  6. Examining works of art and historical artefacts in order to preserve and repair them.

Advantages of Bright Field Microscope

There are several advantages to using a bright field microscope:

Simple to Use: Bright field microscopes are simple and straightforward to operate, making them a popular option for novices and educational settings.

High Quality: They are capable of producing high-quality images with exceptional contrast and resolution of bright field microscope, enabling the observation and analysis of specimens in great detail.

Affordable: In comparison to other types of microscopes, such as electron microscopes, bright field microscopes are comparatively affordable.

Versatile:  Bright field microscopes are versatile and can be used to observe several specimens, including cells, tissues, and living organisms.

Common: Bright field microscopes may be found in the majority of laboratories and educational institutions. They are convenient for usage with a range of samples.

In general, bright field microscopes are a useful instrument for a variety of purposes and a viable option for many types of microscopy work.

Disadvantages of Bright Field Microscope

There are several disadvantages of a bright field microscope:

Limited contrast: Bright field microscopes don’t have as much contrast as dark field or phase contrast microscopes. This can make it hard to picture certain details or structures in a sample.

Lack of detail: The wavelength of light used to light the sample limits the resolution of bright field microscope. This can make it hard to see small structures or details in the sample.

Poor visibility: Bright field compound microscope rely on the sample to absorb light to make an image. This makes it hard to see transparent or colorless objects. This means that objects that are clear or have no color might not be able to be seen or might look washed out in a bright field microscope.

Limits Sample: Bright field compound microscope can only take good pictures of thin, clear samples. This can limit the types of samples that can be looked at and may mean that the samples need to be prepared in a lot of detail before imaging.

Sensitive to light: Bright field compound microscope are sensitive to light and can be hard to use when there isn’t much of it. This can be a problem when working with living samples that need a certain amount of light to stay alive.

FAQ

FAQs on Bright-Field Microscope Principle and Working

A bright field microscope is a type of optical microscope that uses transmitted light to illuminate a sample, which is then observed through the microscope’s eyepieces.

Bright field microscopy is used for a wide range of applications, including: Examining cells and tissues, Observing bacteria and other microorganisms, Analyzing samples in materials science, Quality control in manufacturing, Research and education.

Bright field microscopy is a simple type of microscopy that uses white light to illuminate a sample and an objective lens to focus the light on a detector, like the human eye or a camera.

Robert Hooke devised the bright field microscope in the 17th century. Hooke was an English polymath and scientist best recognised for his contributions to microscopy and the area of biology.

Bright field microscopy is used for a wide range of applications, including: Examining cells and tissues, Observing bacteria and other microorganisms, Analyzing samples in materials science, Quality control in manufacturing, Research and education.