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Printer Friendly Microscopes are useful tools for visualizing small structures in great detail. There are two common types of microscopes used in laboratories when studying algae: the compound light microscope (commonly known as a light microscope) and the stereo microscope (commonly known as a dissecting microscope). A light microscope is used to visualize objects flattened onto glass slides in great detail. It typically has a magnification power of up to 1000x. A light microscope might be used when examining individual cells within living tissue. A dissecting microscope is used to view three-dimensional objects and larger specimens, with a maximum magnification of 100x. This type of microscope might be used to study external features on an object or to examine structures not easily mounted onto flat slides. Both microscopes have similar features. Each microscope has an eyepiece as well as a light source. Light microscopes usually have eyepieces that are magnified 10x plus multiple objective lenses that are magnified between 4x and 100x (SF Fig. 2.2 A). The total magnification is calculated by multiplying the eyepiece magnification (10x) by the objective lens magnification (e.g., 40x), for a total magnification would be 400x. On a light microscope, a sample is placed on a glass slide and light is passed through the sample from underneath the stage. This type of microscope shows great detail of small, thin objects. To view thicker objects, the tissue sample must be thinly sliced and prepared on a glass slide in two-dimensions. With a dissecting microscope whole objects can be viewed in three dimensions. Samples do not need to be sliced, and larger, live animals can be observed. Light can be passed through from underneath the sample, but also from the top or side using an external light source. However, the magnification power of the dissecting microscope is less powerful than that of a light microscope. Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. � University of Hawai�i, 2011. This document may be freely reproduced and distributed for non-profit educational purposes. A compound microscope is a microscope that uses multiple lenses to enlarge the image of a sample. Typically, a compound microscope is used for viewing samples at high magnification (40 - 1000x), which is achieved by the combined effect of two sets of lenses: the ocular lens (in the eyepiece) and the objective lenses (close to the sample). Light is passed through the sample (called transmitted light illumination). Larger objects need to be sliced to allow this to happen efficiently. Compound microscopes usually include exchangeable objective lenses with different magnifications (e.g 4x, 10x, 40x and 60x), mounted on a turret, to adjust the magnification. These microscopes also include a condenser lens and iris
diaphragm, which are important for regulating how light hits the sample. The vast majority of microscopes have the same 'structural' components:
StereomicroscopesThe stereo- or dissecting microscope is an optical microscope variant designed for observation with low magnification (2 - 100x) using incident light illumination (light reflected off the surface of the sample is observed by the user), although it can also be combined with transmitted light in some instruments. It uses two separate optical paths with two objectives and two eyepieces to provide slightly different viewing angles to the left and right eyes. In this way it allows a three-dimensional visualization of the sample.  Depth of field is the distance between the nearest and farthest points in a sample that appear sharp in the viewed image. Great working distance and depth of field are important qualities for this type of microscope, allowing large specimens such as small animals, plants and organs to be viewed with most parts in focus at the same time. In addition to the ocular and objective lens, stereomicroscopes typically contain:
Many stereomicroscopes also have adjustable magnification. The stereomicroscope should not be confused with a binocular compound microscope, which has double eyepieces. The image in such a binocular compound microscope is no different from that obtained with a single monocular eyepiece. Learn about the research microscopes scientists use here. When would you use a compound light microscope rather than a dissecting microscope?A light microscope might be used when examining individual cells within living tissue. A dissecting microscope is used to view three-dimensional objects and larger specimens, with a maximum magnification of 100x.
What is the difference between a compound microscope and a dissecting scope?Dissecting microscopes are useful for observing the surface features of the specimen. On the other hand, a compound microscope is meant for looking through the specimen. Also, a compound microscope has a higher magnification ranging from 400X to up to 1000X while a dissecting microscope can magnify to a maximum of 70X.
Why would you use a compound light microscope?Compound microscopes are used to view small samples that can not be identified with the naked eye. These samples are typically placed on a slide under the microscope. When using a stereo microscope, there is more room under the microscope for larger samples such as rocks or flowers and slides are not required.
Why is a dissecting microscope sometimes better than using a light microscope?Further, the dissecting microscope is more useful when viewing objects with low magnification like organ tissues, whereas, the compound light microscope is used for viewing objects not visible with the naked eye like cells, or objects that need to be viewed in finer detail like blood samples.
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Would you use a compound light microscope or a dissecting scope to view these items
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