| Ramsden eyepiece | <microscopy> An ocular consisting of two plano-convex lenses with the plane side of the lower lens nearer the objective. The focal plane is outside the system, hence it is of the positive type with the diaphragm below the lenses. While this eyepiece gives a somewhat flatter field than the Huygenian and for this reason has been used in the past for micrometre oculars, the colour correction is poor with the formation of colour fringes around the object. The modern Ramsden eyepiece has an achromatic doublet for the eye lens to correct for colour. (05 Aug 1998) |
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| Ramsden circle | <microscopy> The circular spot of light formed at that distance above the eyepiece where the chief image forming rays cross, the back focal plane of the eyepiece. The objective back focal plane is in conjugate focus in this same plane. In visual microscopy, the point where the pupil of the eye is placed. (05 Aug 1998) |
| Ramsden disk | <microscopy> The small circular patch of light that appears at the eyepoint above the ocular lens. This is the exit pupil of an optical instrument that, in a microscope adjusted for Koehler illumination, lies in a plane conjugate with the objective rear focal plane, condenser iris, and light source. Alteration of the Ramsden disk (for example, by the observer's iris) modifies the aperture function, diffraction pattern, and direction of view of the specimen. (05 Aug 1998) |
| Ramsden, Jesse | <person> English optician, 1735-1800. See: Ramsden's ocular. (05 Mar 2000) |
| Ramsden's ocular | An eyepiece of a microscope, consisting of two planoconvex lenses with convexities turned to each other. (05 Mar 2000) |
| reticle eyepiece | <microscopy> A microscope ocular having at its focal plane a reticle. (05 Aug 1998) |
| periplan eyepiece | <microscopy> A compensating type of eyepiece made by Leitz with a doublet for the eyelens. The field is larger and flatter than the regular compensating ocular, but there is apt to be spherical aberration or distortion present near the periphery of the field. (05 Aug 1998) |
| planoscopic eyepiece | <microscopy> An American Optical Company (Reichert) eyepiece designed to flatten the field of achromatic objectives. (05 Aug 1998) |
| widefield eyepiece | <microscopy> An ocular with an achromatic doublet for the eyelens and with the plane side of the lower lens nearest the objective. Such a corrected system does not have to be stopped down with a diaphragm, hence a large flat field is achieved. A positive achromatic eyepiece, having a large eye lens and a high eye point, intended primarily for use with widefield binocular microscopes. (05 Aug 1998) |
| holoscopic eyepiece | <microscopy> An eyepiece suitable for achromatic, fluorite and apochromatic objectives. The eyelens can be adjusted closer to or further away from the field lens to spherically correct for the various types of objectives. (This adjustment also changes the magnification of the eyepiece.) (05 Aug 1998) |
| Huygenian eyepiece | <microscopy> An under corrected (blue rim at periphery of field) ocular designed by Huygens for the telescope and later adopted for achromatic objectives. This ocular consists of two plano-convex lenses separated by a diaphragm, hence it is of the negative type with the focal plane inside the system. Both plane surfaces face the eye, as distinguished from the Ramsden eyepiece. (05 Aug 1998) |
| hyperplane eyepiece | <microscopy> A special eyepiece made by Bausch & Lomb for flattening the visual field. (05 Aug 1998) |
| negative eyepiece | <microscopy> An eyepiece in which the real image of the object is formed between the lens elements of the eyepiece. (05 Aug 1998) |
| eyepiece | <microscopy> The lens system used in an optical instrument for magnification of the image formed by the objective. (05 Aug 1998) |
| eyepiece, negative | <microscopy> An ocular in which the real image of the object is formed between two lenses. The Huygens type. (05 Aug 1998) |
| Ramsden's eyepiece |
(Rams
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제품명 |
판매사 |
보험코드 | 성분/함량 | 구분/보험급여 |
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제품명 |
판매사 |
보험코드 | 성분/함량 | 구분/보험급여 |
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