A microscope is used to view objects that are extremely small. The microscope acts like a high-powered magnifying glass and makes the object appear large and easy to see when you look through the eye piece. Scientists can examine cells and small organisms using a microscope. This helps them research viruses and better understand how life functions at the microscopic level. It is also used to examine DNA evidence in criminal cases.
There are typically two lenses in a basic microscope. One is located at the end the viewer looks through, and the other is found at the end closest to the object under examination. Light shines onto the object and creates a reflection inside this tube. What the viewer sees is an enlarged version of the reflection. The lens closest to the object tries to focus the object itself. The lens near your eye helps your eye focus on the object. When the microscope is used properly, headaches from lack of focus or eye strain should not occur.
Microscopes vary in complexity, but they all include the same basic parts. Understanding the basic parts of the microscope helps you to understand why a more expensive microscope with extra features may be an advantage over a basic microscope. Microscopes that use light illumination, the type that are found in high school classes and science labs, contains the ocular lens to look through, the objective lens or lenses that is closest to the object, a light source, an arm to connect the microscope, and a stage to hold the slide. Adjustment knobs are also added to help focus the microscope.
Microscopes are divided into four categories. The two light illuminated microscopes are compound microscopes and dissection microscopes. The compound microscope is the most common and creates a highly detailed two-dimensional image of the object. The dissection microscope creates lower quality, three-dimensional images of the object.
The other two types of microscopes, the scanning electron microscope (SEM) and the transmission electron microscope (TEM), are much larger and more advanced than light-illuminated microscopes. They use electron illumination to create the images seen. The SEM creates 3D images, while the TEM creates 2D images.
Credit for the microscope's invention is typically given to Galileo or Zacharias Janssen, though others have improved upon the design to help move us toward the microscope we have today. Zacharias Janssen, a spectacle maker working in Middleburg,
Step 1: Set up your microscope and make sure that the lens is clean. Get your slide ready and slide it onto your microscope. Adjust the focus until you get it to the right level.
Step 2: Now that the microscope is ready to go, you'll need to get your camera ready. Make sure that it's lens are also clean, as any dust and smudges will be readily noticeable. Once the camera is clean, you can set up your tripod if you have one. Tip it so that the lens of the camera sits about 1/2" to 1" above the lens of the microscope. Using black construction paper, make a loose-fitting tube that go in-between the two lens to keep the light out. You may need to adjust the camera's distance to get a clear picture.
Step 3: Using the self timer feature on the camera, have the picture delay about 2 seconds. This will give the camera time to stop vibrating from the motion of pushing the camera button. Press the button, stand back, and wait for the picture to be taken - it should be clear and easy to see.
Step 4: Import your picture into Photoshop or GIMP. You'll need to crop the extra black from the picture. You can either retain the circular picture, or crop it in a traditional square shape using the image guides and line tool.
1. When moving your microscope, always carry it with both hands (Figure 1, below). Grasp the arm with one hand and place the other hand under the base for support.
2. Turn the revolving nosepiece so that the lowest power objective lens is "clicked" into position (This is also the shortest objective lens).
3. Your microscope slide should be prepared with a coverslip or cover glass over the specimen. This will help protect the objective lenses if they touch the slide. Place the microscope slide on the stage and fasten it with the stage clips. You can push down on the back end of the stage clip to open it.
4. Look at the objective lens and the stage from the side (Figure 2) and turn the coarse focus knob so that the objective lens moves downward (or the stage, if it moves, goes upward). Move it as far as it will go without touching the slide!
5. Now, look through the eyepiece and adjust the illuminator (or mirror) and diaphragm (Figure 3) for the greatest amount of light.
6. Slowly turn the coarse adjustment so that the objective lens goes up (away from the slide). Continue until the image comes into focus. Use the fine adjustment, if available, for fine focusing. If you have a microscope with a moving stage, then turn the coarse knob so the stage moves downward or away from the objective lens.
7. Move the microscope slide around so that the image is in the center of the field of view and readjust the mirror, illuminator or diaphragm for the clearest image.
8. Now, you should be able to change to the next objective lenses with only minimal use of the focusing adjustment. Use the fine adjustment, if available. If you cannot focus on your specimen, repeat steps 4 through 7 with the higher power objective lens in place. Do not allow the objective lens to touch the slide!
9. The proper way to use a monocular microscope is to look through the eyepiece with one eye and keep the other eye open (this helps avoid eye strain). If you have to close one eye when looking into the microscope, it's ok. Remember, everything is upside down and backwards. When you move the slide to the right, the image goes to the left!
10. Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses.
11. When finished, raise the tube (or lower the stage), click the low power lens into position and remove the slide.
12. Always keep your microscope covered when not in use. Dust is the number 1 enemy!
Remember, microscopes are expensive scientific instruments. Handle them properly and carefully and they will last for many years!
Microscope magnification=Eyepiece magnification X Objective magnification.
e.g. One Microscope equipped with Eyepiece WF10x and Objective 4x, 10x, 40x, 100x, then microscope magnification would be 40x, 100x, 400x, and 1000x.
1. Do the cameras come with a program for capture and measuring? Yes 2. Can it work in chromatic and black-and-white mode? yes 3. Are there Peltier cooling system based to reduce the noise of the image? no 4. What is the time of exposure? 1-3000ms 5. Can the camera work with a computer by velocity connection FireWire? no, USB2.0 only