1) why are images produced under the microscope reversed & inverted?
2) why does a specimen need to be centered in the field of view on low power before going to high power?
1. I know this is a poor answer but it's the best I can do. The images are reversed and inverted because that's what lenses do.
2. At high power it takes VERY LITTLE movement to take the specimen out of the field of view; therefore, you want to get it centered and you do that with low power and you have a relatively large field of view.
1) Images produced under the microscope are reversed and inverted due to the optical properties of the lenses. To understand why this happens, let's briefly explain the structure of a compound microscope.
A compound microscope consists of two sets of lenses: the objective lens and the eyepiece lens. The objective lens is located close to the specimen and magnifies the image, while the eyepiece lens further enlarges the image for our eyes to see.
When light passes through the objective lens, it undergoes several refractions and produces an intermediary image called the "real image." This real image is then further magnified by the eyepiece lens to create the final "virtual image" that we observe.
Due to the arrangement of lenses and the refraction of light, the real image formed by the objective lens is flipped vertically (reversed) and flipped horizontally (inverted). This inverted and reversed image is then magnified by the eyepiece lens, leading to the same orientation of the virtual image we observe through the eyepiece.
2) It is important to center the specimen in the field of view on low power before switching to high power on a microscope for several reasons. Let's go through the reasons below:
a) Field of View: The field of view refers to the area visible through the eyepiece when looking into the microscope. On low power, the field of view is larger, and it becomes narrower on higher magnifications. By centering the specimen in the field of view on low power, you have a better chance of keeping it in view when you switch to high power, where the field of view is smaller.
b) Focus: On low power, the image of the specimen appears relatively larger, allowing you to easily locate and focus on it. Once the specimen is centered and focused on low power, switching to high power will maintain the position of the specimen in the center, making it easier to re-focus without losing sight of it.
c) Slides and Stage Adjustments: Some microscopes have a mechanical stage that allows for precise movement of the slide in both X and Y directions. By centering the specimen on low power, you can conveniently adjust the slide position using the stage controls, ensuring that the specimen stays centered as you switch to higher magnifications.
In summary, centering the specimen in the field of view on low power before moving to high power helps maintain the specimen in view, facilitates easier focus adjustments, and allows for convenient slide and stage adjustments.