When setting up a compound microscope, it is important to optimize the illumination in order to produce clear and crisp images. There are four areas that should be considered when setting up the microscope illumination. Show
The microscope rheostat control can be found on the side of the compound microscope body. It will typically be a knob that is turned clockwise in order to increase the light intensity, or counter-clockwise to reduce the light. The image at left shows the rheostat control on the Zeiss digital Primostar microscope circled in red. Some microscopes have a recessed dial that is rotated to the right to increase the intensity and to the left to decrease light intensity. #2 - Using a Light Filter Depending what type of illumination your compound microscope has, you may need to use a daylight balancing filter. This is a blue filter and it usually sits directly on top of the illuminator, or in a filter holder above the light. If your microscope has tungsten or halogen illumination, the daylight balancing filter will correct the color temperature and result in a better quality image (and a better color image). If you have an LED microscope, this blue filter will not be needed. Microscopes that have LED illumination have a color temperature that is already high and does not need to be adjusted. The image below shows what your microscopy image may look like if you have a tungsten or halogen microscope and are not using a daylight balancing filter (left) versus what it will look like if you are using the daylight balancing filter (right). #3 - Adjusting the Aperture Diaphragm
If you’re starting your PhD or post-doctoral work, chances are you’ll need to use a light microscope at some stage during your research. Some of you may be seasoned microscopists. For many of you though, this might be the first time you’ve ever plugged in a microscope, or at least the first time you’ve used one since some long-forgotten undergraduate histology course. Yet somehow you’re expected to just dust off that old ‘scope in the corner of the lab, and start using it as if you’re an old hand. Have no fear – help is at hand! In today’s article, I’m going to go over the basics of the light microscope. The anatomy of the light microscopeTo begin with, I’d like to introduce you to the parts of the microscope – basically the bits that might be useful for you to know about. No optical physics required!
Viewing your slidesOK, so now that you know all the parts of the microscope, let’s look at your first slide. What do you do first?
Hopefully, this overview has taken some of the mystery out of using your lab’s ancient light microscope. It can be a nightmare if you’re faced with using a microscope for the first time, but following these few, easy steps should ease the pain a little! What part of the microscope increases or decreases light intensity?Condenser Diaphragm- This diaphragm controls the amount of light entering the lens system. This feature is useful for viewing unstained biological specimens that are translucent. Reducing the amount of light improves contrast, making the specimen "stand out" against the background.
What part of the microscope controls the light intensity?Iris Diaphragm: A rotating disc under the stage that controls the intensity of light hitting the specimen.
Does the light intensity increase or decrease as the magnification increases?When an individual increases the magnification of objects viewed on the microscope stage, the light intensity gradually reduces. This occurs because magnification focuses on a smaller area, and hence the light gets scattered and specimen becomes less focused.
Which part of the microscope is used to adjust the intensity brightness of the light passing through the specimen on the stage?Light from the light source then passes through the condenser which focuses the light on the specimen. An iris diaphragm is used to control the intensity, or brightness, of light which passes through the specimen, thus allowing the operator to adjust the intensity and achieve an optimum viewing contrast.
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