Bright field simple microscope
- 1. BRIGHT FIELD SIMPLE MICROSCOPE AVANISH DIXIT Roll NO- DEP.- AAHM
- 3. DISCRIPTION; DEFINITION AND HISTORY • What is the Brightfield simple microscope? • Bright-field microscopy is the simplest of a range of techniques used for illumination of samples in light microscopes, and its simplicity makes it a popular technique. • This is Simple Microscope is a type of optical Microscope or light Microscope. • This is the most elementary form of microscopy illumination techniques and is generally used with compound microscope. • A Brightfield simple microscope is used to see the magnified image of an object. • The main property of this microscope is convex lens is to produce a virtual, erect and enlarge image when the object is placed within the focal length. • The name “brightfield” derived from the fact that the specimen is dark and contrasted by the surrounding bright viewing field.
- 4. EXAMPLES OF BRIGHTFIELD SIMPLE MICROSCOPE
- 5. History- Antoine van Leeuwenhoek, a Dutch, invented the first simple microscope, consisting of a small single high powered converging lens to inspect the small microorganism in a drop of freshwater and credited to bringing attention to the biologist. He saw bacteria and fungi algae and yeast through it. From his great contributions, many discoveries and research papers, Anthony Leeuwenhoek (1632-1723) has since been called the "Father of Microscopy". The early “Brightfield simple microscope” which were really only magnifying glasses had one power, usually about 6x- 10x. And this glasses called as “flea glasses”.
- 6. THE MAIN USE OF BRIGHT FIELD SIMPLE MICROSCOPE 1. A microbiologist used it for examining and studying microscopic fungi, algae, and other biological specimens that are difficult to visualize using the naked eyes. 2. A dermatologist or skin specialist used it to check for various skin diseases. 3. It also can be used to visualize the scale pattern of fishes means in field of SCUAMATION. small parts of the jewelry, to magnify a tiny part of the watch. magnify various particles of various types of soils.
- 7. MAIN PARTS OF BF-SIMPLE MICROSCOPE • Eyepiece: It is the lens that is used to study the samples and is placed at the top. It has a magnification of 10X to 15X. • Base: This provides support to the microscope. • Tube: This is used to connect the eyepiece to the objective lenses. • Objective lenses: These are found with the magnification of 10X, 40X and 100X and are colour coded. The lower power lenses are the shortest lens and the highest power lenses are the longest lens. • Revolving nose-piece: This is also known as the turret. It is used for holding of other objective lens and can be rotated while viewing the samples.
- 8. CONT….. • Diaphragm: It is used to control the amount of light that passes through the stage. • Stage: It is the platform used for placing the slides with samples. • Stage clip: These are used to hold the slides in the proper place. • Coarse adjustment knob: It is used to focus on scanning. • Fine adjustment knob: It is used to focus on oil. • Arm: It is used to support the tube and connects to the base of the microscope. • Power switch: The main power switch used to turn on or off the microscope. • Condenser: It is used to focus the light on the sample and 400X power lenses are used
- 10. WORKING PRINCIPLE OF BF-SIMPLE MICROSCOPE When you place a tiny object or specimen in front of a simple microscope’s lens within its focus, then a virtual, erect and magnified image of the object is formed at the least distance of distinct vision from the eye held close to the lens. A simple microscope is one that uses a single lens for magnification, such as a magnifying glass to enhance the magnification of an object. It uses a lens to enlarge an object through angular magnification alone, giving the viewer an erect enlarged virtual image It is actually a convex lens of small focal length, which is used for seeing the magnified images of small objects.
- 12. Working Mechanism of Simple Microscope This ray diagram in below, explains how simple microscopes is working; 1. A small object AB which is to be magnified is placed between the principal focus F’ and optical center C of the convex lens. 2. Now, a ray of light AO parallel to a principal axis which is coming from point A of the object passes through the focus F along the straight line OX after getting refracted by the convex lens.
- 13. RAY DIAGRAM OF BF-SIMPLE MICROSCOPE 3.A second ray of light AC coming from the point A of the object passes through the optical center C of the convex lens along the straight line CY. 4.As is clear from the figure that the two rays i.e. OX and CY are diverging rays so these rays can intersect each other only at point A’ when produced backward. 5.Now, on drawing A’B’ perpendicular from point A’ to the principal axis,
- 14. Magnification of a BF-Simple Microscope The magnifying power of simple microscopes is given by: M = 1 + D/F Where, D = the least distance of distinct vision F = focal length of the convex lens It should be noted, • Smaller the focal length of the lens, greater will be itsmagnifying power. • This microscope has a maximum magnification power of 10, which means the specimen will appear 10 times larger by using the simple microscopes of maximum magnification.
- 15. LIMITATION OF BF-SIMPLE MICROSCOPE The main limitation of light microscopes are, that they have a lower resolution and cannot see beyond 200nm. And it cannot see smaller organelles like ribosomes. Brightfield microscopy has very low contrast and most cell absolutely have to stained to be seen staining may introduced extraneous details in to the specimens that should not be present. Also the user need to be knowledge in proper staining techniques. Lastly this method requires a strong light sources for high magnifications and intense lighting can produce heat that will damage specimens or kill living microorganism. By using an aperture diaphragm for contrast, past ascertain point, greater contrast adds distortion. However, employing an iris diaphragm will help compensate for his problem.
- 16. Limitations… Brightfield simple microscopy cant be used to observe living specimen of bacteria, although when using fixed specimens, bacteria have an optimum viewing magnification of 1000x. And it is increasing the magnifying power is determined by the value of focal length and the closeness with which the lens can be held near the eye. IT Has low contrast for weakly absorbing samples and low resolution due to the blurry appearance of out-of-focus material. Certain disadvantages are inherent in nay optical imaging technique.
- 17. LIMITATION OF BF-SIMPLE MICROSCOPE Simple microscope comprises of single biconvex lens used as a magnifying glass. Natural light is the source to see the objects. The condenser lens is not present. Non-adjusting magnification that is it provides only one level of magnification which depends on the used lens in the microscope. Magnifying power is up to 300 times It is used for the basic purposes such as reading and magnifying glass.
- 18. Advantages Brightfield microscope is a very simple to use with fewer adjustment needed to be made to view specimens. Some specimen can be viewed without staining and the optics and the optics used in the brightfield technique don’t alter the colour of the specimen. It is adaptable with new technology and optional pieces of equipment can be implemented.
- 19. References Bright-field microscopy – Wikipedia Simple Microscope - Definition, Types, Working Principle & Formula (vedantu.com) Bright Field Microscope: Definition, Parts, Working Principle, Application. (microbiologynote.com) Microscopy (slideshare.net) Simple Microscope Definition, Magnification, Parts And Uses (byjus.com) Microscope: Structure, Uses, Functioning Processes of Simple , Compound Microscope (brainkart.com)