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The stereo or stereoscopic or dissecting microscope is an optical microscope variant designed for low magnification observation of a sample, typically using light reflected from the surface of an object rather than transmitted through it. The instrument uses two separate optical paths with two objectives and eyepieces to provide slightly different viewing angles to the left and right eyes. This arrangement produces a three-dimensional visualization of the sample being examined.〔("Introduction to Stereomicroscopy" ) by Paul E. Nothnagle, William Chambers, and Michael W. Davidson, ''Nikon MicroscopyU''.〕 Stereomicroscopy overlaps macrophotography for recording and examining solid samples with complex surface topography, where a three-dimensional view is needed for analyzing the detail. The stereo microscope is often used to study the surfaces of solid specimens or to carry out close work such as dissection, microsurgery, watch-making, circuit board manufacture or inspection, and fracture surfaces as in fractography and forensic engineering. They are thus widely used in manufacturing industry for manufacture, inspection and quality control. Stereo microscopes are essential tools in entomology. The stereo microscope should not be confused with a compound microscope equipped with double eyepieces and a binoviewer. In such a microscope, both eyes see the same image, with the two eyepieces serving to provide greater viewing comfort. However, the image in such a microscope is no different from that obtained with a single monocular eyepiece. ==Differences to normal optical microscopes== Unlike a compound light microscope, illumination in a stereo microscope most often uses reflected illumination rather than transmitted (diascopic) illumination, that is, light reflected from the surface of an object rather than light transmitted through an object. Use of reflected light from the object allows examination of specimens that would be too thick or otherwise opaque for compound microscopy. Some stereo microscopes are also capable of transmitted light illumination as well, typically by having a bulb or mirror beneath a transparent stage underneath the object, though unlike a compound microscope, transmitted illumination is not focused through a condenser in most systems.〔("Illumination for Stereomicroscopy: Reflected (Episcopic) Light" ) by Paul E. Nothnagle, William Chambers, Thomas J. Fellers, and Michael W. Davidson , ''Nikon MicroscopyU''.〕 Stereoscopes with specially-equipped illuminators can be used for dark field microscopy, using either reflected or transmitted light.〔("Illumination for Stereomicroscopy: Darkfield Illumination" ) by William Chambers, Thomas J. Fellers, and Michael W. Davidson , ''Nikon MicroscopyU''.〕 Great working distance and depth of field are important qualities for this type of microscope. Both qualities are inversely correlated with resolution: the higher the resolution (''i.e.'' the greater the distance at which two adjacent points can be distinguished as separate), the smaller the depth of field and working distance. Some stereo microscopes can deliver a useful magnification up to 100×, comparable to a 10× objective and 10× eyepiece in a normal compound microscope, although the magnification is often much lower. This is around one tenth the useful resolution of a normal compound optical microscope. The large working distance at low magnification is useful in examining large solid objects such as fracture surfaces, especially using fibre-optic illumination. Such samples can also be manipulated easily so as to determine the points of interest. There are severe limitations on sample size in scanning electron microscopy, as well as ease of manipulation in the specimen chamber. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Stereo microscope」の詳細全文を読む スポンサード リンク
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