Microscopes

Parts of the light Microscope 1. Ocular lens or eyepiece: most are 10x magnification. The scopes used are binocular (two eyepieces). 2. Body tube: contains mirrors and prisms which direct the image to the ocular lenses. 3. Nosepiece: holds the objective lenses, rotates 4. Objective lenses: usually 3-4 on our scopes, 4x, 10x, 43x, 100x oil immersion (red banding). Total magnification = ocular power x objective power. Most of our binocs have fixed position lenses--the stage moves up and down rather then the lens. 5. Stage: Movable platform on which slides are mounted for viewing; all of the scopes have mechanical stages with X,Y vernier scales. Focus knobs move the stage up and down. 6. Condensor: A substage lens which focus the light on the specimen. The binocs have condensors that move up and down to focus the light beam. 7. Iris Diaphragm: the diaphragm is located just below the stage and controls the amount of light which passes to the specimen and can drastically affect the focus of the image. 8. Focusing knobs: outermost is the fine focus and innermost is the coarse focus. On the binocs these knobs control up/down movement of the stage. 9. Light source: The scopes have built in light sources. The rheostat ON/OFF switch is located either on the scope or on the external power supply and is used to regulate light intensity.

Centering the specimen before switching to high power helps ensure that you are viewing the area of interest in focus. It helps prevent the objective lens from hitting the slide, which can damage both the lens and the specimen. Additionally, centering the specimen can improve the image quality by reducing glare and shadowing.

Increasing the magnification of a microscope typically decreases the working distance, or the distance between the objective lens and the specimen. Higher magnification requires the objective lens to be closer to the specimen to achieve focus, reducing the working distance. Similarly, lower magnification allows for a greater working distance between the lens and the specimen.

You do not use the coarse focus knob on high power because it can damage the slide and the objective lens of the microscope. Use only the fine focus knob to bring the specimen into sharp focus on high power.

TEM (transmission electron microscope) and SEM (scanning electron microscope) use electron beams instead of light to magnify specimens, providing higher resolution images. Compound microscopes use visible light and lenses to magnify specimens. TEMs transmit electrons through the specimen to create an image, while SEMs scan the specimen's surface with electrons to generate an image.

The objective lens is the part of the microscope that helps to make an object look larger by magnifying its image.

The limit of magnification for a light microscope is around 2000 times due to the wavelength of visible light, which affects the resolution of the image. Beyond this point, the details of the specimen become blurry and cannot be resolved. To achieve higher magnifications, electron microscopes that use electron beams instead of light are used.

Electron microscopes were invented to overcome the limitations of light microscopes, which have a limited resolution due to the wavelength of visible light. Electron microscopes use a focused beam of electrons to achieve much higher magnification and resolution, allowing scientists to see smaller details in samples such as cells, bacteria, and structures at the atomic level. This has revolutionized our understanding of the microscopic world and has applications in various fields such as biology, materials science, and nanotechnology.

The focusing mechanism in a camera lens adjusts the lens elements to ensure that the subject being photographed appears sharp and clear in the image. It allows the lens to maintain precise focus on different subjects at varying distances. By manipulating the focusing mechanism, photographers can achieve desired depth of field effects and control the sharpness of their images.

An image is created by a scanning electron microscope (SEM) by scanning a focused beam of electrons across the surface of a sample. As the electrons interact with the sample, they produce various signals, such as secondary electrons and backscattered electrons, which are then detected and converted into a grayscale image. The image represents the topography of the sample at a very high resolution, providing detailed information about its surface characteristics.

When you pull the arm of the microscope towards you, it adjusts the distance between the objective lens and the specimen. This movement helps to focus the image by bringing the specimen into sharper view.

The inclination joint connects the head and the arm of the microscope. This movement allows for tilting and adjusting the angle of the microscope head, making it easier to view specimens from different angles and positions.

In an electron microscope, the condenser lens is comparable to the condenser lens in a light microscope, as both concentrate and direct the light/electron beam onto the specimen. The objective lens in an electron microscope is similar to the objective lens in a light microscope, as both magnify the specimen image. Additionally, both types of microscopes have a stage where the specimen is placed for observation.

The mechanical stage controls the movement of the specimen slide from left to right and front to back in a microscope. This allows for precise positioning and focusing of the specimen under the lenses.

Electrons do not bounce off objects in microscopy. In electron microscopy, electrons pass through a thin slice of the object and interact with it to create an image with high resolution. Scanning electron microscopes (SEMs) use a beam of focused electrons to scan the surface of a specimen and create detailed images.

The microscope that uses beams of electrons to produce magnified images is called an electron microscope. It has a much higher magnification and resolution capability compared to a light microscope, allowing for detailed examination of very small structures.

To find the new field of view at 400X magnification, you would divide the original field of view by the magnification increase factor (which is 10 in this case since you are going from 40X to 400X). So, 6000 um / 10 = 600 um. Therefore, the field of view at 400X magnification would be 600 micrometers.

The fine focusing mechanism on a microscope is used to make small adjustments to the focus of the specimen being viewed. This allows for precise clarity and detail to be achieved when observing the specimen under high magnification.

The coarse focusing mechanism in a microscope is used to quickly adjust the distance between the objective lens and the specimen to roughly bring the specimen into focus. This allows the user to start focusing on the specimen before making fine adjustments with the fine focusing mechanism for a clear and detailed image.

When you move the coarse adjustment knob on a microscope, it raises or lowers the stage quickly, allowing you to bring the specimen into rough focus. This knob is used to make large adjustments to the focus of the image.

If only half of the field is illuminated in a microscope, the image will appear dimmer as there is less light available to form the image. This may make it harder to visualize details and can affect the quality of observation. Adjusting the lighting to evenly illuminate the field will provide a clearer and brighter image for better analysis.

When only half of the field is illuminated in a microscope, it may be due to uneven lighting from the light source or improper adjustment of the mirror or condenser. Ensure the light source is evenly distributed across the field, adjust the mirror or condenser to center the light properly, and make sure the specimen is in focus to maximize illumination.

A phototube in a microscope is used to capture images of the specimen being observed by converting light signals into electrical signals. These electrical signals can then be processed and displayed on a screen or printed out for further analysis or documentation. It allows researchers to document and analyze the samples they are studying in greater detail.

Electron microscopes use a beam of accelerated electrons to view objects at extremely high magnifications. The electrons interact with the sample to produce images with much higher resolution than can be achieved with light microscopes.

The small aperture and focal length of a microscope objective allow for high resolution and magnification by increasing light-gathering ability and minimizing aberrations. A small aperture increases depth of field and improves contrast, while a short focal length reduces spherical aberration and increases optical performance.