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RM2BTXTN3–Dark field light micrograph of yellow pond lily (Nuphar polysepala) pollen grains, pictured area is about 160 micrometers wide
RM2HHC3MT–Microscopic free-living nematode worm from garden soil, possibly Panagrellus sp., dark field micrograph, horizontal field of view is about 1.1mm
RME68D8E–Common Pheasant Phasianus colchicus, mircoscopy is used to image feather barbules using dark field illumination, Nottingham.
RMMBNRWK–Dark field light micrograph of Lactarius rubrilacteus (bleeding milkcap) mushroom spores, pictured area is about 120 microns wide
RM2J22REN–Dark field micrograph of a mosquito wing, horizontal field of view is approximately 0.61 mm
RF2CAGMH5–Microscopic view of a Horsetail (Equisetum arvense) spores with elaters. Polarized light with crossed polarizers.
RM2HR274K–Human cheek epithelial cells under the microscope, horizontal field of view is about 125 micrometers
RM2FX7AAE–Dark field photomicrograph of fresh-water algae, horizontal field of view is about 121 micrometers
RM2GK94FE–diatom (Diatomeae), Diatoms from Emeralda, light microscopy, dark-field microscopy, magnification x 140 related to a print of 35 mm width, USA,
RM2G9YYCT–House fly (Musca domestica), mouthparts of a house fly (dark field, and DIC microscopy, UV light)
RMMM85PT–Dark field light micrograph of Verpa bohemica mushroom spores, pictured area is about 0.65mm wide
RMT9XY9A–Thrips (probably Thripidae), dark field micrograph, field of view is approximately 0.61mm high (on-sensor magnification 28x)
RMK0C5X0–Broken diatom frustule from a fresh water sample (about 120 microns in length), dark field micrograph
RF2CAGMH7–Microscopic view of a Horsetail (Equisetum arvense) spores with elaters. Polarized light with crossed polarizers.
RMKW111K–Photomicrograph of a Treponema pallidum bacterium using dark field microscopy technique. Mag 400x, Dark field microscopy involves the application of light rays in an oblique manner to microscopic specimens in order to illuminate these organisms, which are normally difficult to see using normal lighting techniques. Image courtesy CDC/Schwartz, 1961.
RM2G9YY70–House fly (Musca domestica), mouthparts of a house fly (dark field, and DIC microscopy, UV light)
RMKR0171–Dark field micrograph of a stain edge on a prepared microscope slide, pictured area is about 0.8mm wide
RMRHKYEN–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SPENCER. 1 ASSURES MAXIMUM OPTICAL PERFORMANCE OF YOUR MICROSCOPE — Koehler type illumination— ideal for bright field . .. phase . . interference ... polar- izing ... and dark field microscopy and photomicro- graphy. Numerical aperture . . and field diaphragm settings regulated accurately and effectively — permit full resolving power of your microscope. 2 OFFERS WIDE SELECTION OF FILTERS — Eight levels of intensity . . plus daylight, green and red filters . . quickly selectable by simple finger-tip rotation of tur- ret mount
RMRYFAFC–Elementary chemical microscopy elementarychemi00cham Year: 1921 ILLUMINATION OF OBJECTS; DARK FIELD 39 illuminator in which, Fig. 15, a lens is combined with a parabo- loid to bring the rays to a proper focus. t ^v&
RMKR14CT–Photomicrograph of leptospiral microscopic agglutination test with live antigen using dark field microscopy technique, 1961. Leptospirosis is a common global zoonotic disease of man and several warm-blooded animals especially in sub-tropical regions of the world, caused by the spirochete bacteria Leptospira . Image courtesy CDC/Mrs. M Gatton.
RM2G9YYCY–House fly (Musca domestica), mouthparts of a house fly (dark field, and DIC microscopy, UV light)
RMKPP96P–Flammulina velutipes (velvet foot mushroom) growing on a log, with dark field light micrograph of its spores
RM2AWNXM8–The microscope; an introduction to microscopic methods and to histology . Tzer. Cross theNicols. In the dark field will be seen multitudes of shining crystals,and if the preparation is a fresh one in water, part of the smallercrystals will alternately flash and disappear. By observing carefully,some of the larger crystals will be found to remain dark with crossedNicols, others will shine continuously. If the crystals are in such aposition that the light passes through them parallel with the optic Fig. 126. ChamoVs Microscopefor Micro-Chemical Analysis {Jour-nal of Applied Microscopy 1899, p.
RMMA7ERD–. Elementary chemical microscopy . Cover-glass and Slide Gauge. - - In dark-field illumination it is necessary to employ the proper slide thickness for which the reflecting condenser has been designed. So too when using high-power dry objectives, especially those with correction col- lars, it is necessary that we ascertain the thickness of the cover- glass and correct for this thickness either by means of the cor- rection collar of the objective or by lengthening or shortening the draw tube as the case may require. The most satisfactory gauge with which the author is familiar is shown in Fig.
RMRYGD63–Elementary chemical microscopy elementarychemi00cham Year: 1921 40 ELEMENTARY CHEMICAL MICROSCOPY tive. Only those rays included in a low numerical aperture are available. Hence the employment of an objective of high numerical aperture and very short working distance yields a field which is never dark. Since practically all high-power immersion objectives are made with as high numerical apertures as possible, it is absolutely essential that some means be used to reduce their numerical aperture below i, if they are to be employed in dark-field studies. This is accomplished by introducing into
RM2G9YYKE–House fly (Musca domestica), head and mouthparts of a house fly (dark field, and DIC microscopy, UV light)
RM2CD91ND–. The microscopy of vegetable foods, with special reference to the detection of adulteration and the diagnosis of mixtures . e in all the common reagents, including boiling alkali. Insurface view the markings, resembling those of a tortoise shell, which arcdue to the variable thickness of the pigment material, and the rows of MADIA SEED. 199 minute pores appearing as light spots in the dark field, make this layerthe most striking in the fruit. 4. Fiber Bundles (/). The fibers are 5-15 [x in diameter and oftenare i mm. long, being smallest in the outer layers. Between the bundlesare groups of t
RMMA7G29–. Elementary chemical microscopy . Fig. 19. Types of Reflecting Condensers for the Study of Ultramicroscopic Particles. in Fig. 14 will disclose that their inclination is considerably greater. For the chemist the ultracondensers are of far more value than simple dark-field illuminators.1 The Adjustment of Dark-field Illuminators for use requires close attention, chiefly, to five conditions: (1) a selection of a sufficiently powerful radiant and the projection of a spot of light large enough to completely fill the lower opening of the illuminator; (2) the employment of objectives having a numer
RMT0D17J–Electron microscopy; proceedings of the Electron microscopy; proceedings of the Stockholm Conference, September, 1956 electronmicrosco00euro Year: 1957 354 J. H. TALBOT Fig. I. Ray diagram illustrating the principle of the dark- field system. At the right is shown the special annular aper- ture. are collected with a thermal precipitator directly on beryllium films about 30 A thick. After collection they are heated to 550 C to remove organic matter and condensed oil vapour. At the same time the beryllium oxidizes to form a crystalline oxide film, the diffraction pattern of which is used to
RMRD1FHX–. Elementary chemical microscopy. Microscopy; Microchemistry. 168 ELEMENTARY CHEMICAL MICROSCOPY. Cover-glass and Slide Gauge. - - In dark-field illumination it is necessary to employ the proper slide thickness for which the reflecting condenser has been designed. So too when using high-power dry objectives, especially those with correction col- lars, it is necessary that we ascertain the thickness of the cover- glass and correct for this thickness either by means of the cor- rection collar of the objective or by lengthening or shortening the draw tube as the case may require. The most satisfa
RMMA7G2M–. Elementary chemical microscopy . Fig. i 6. Fig. i 8. Fig. 17. Methods of Reducing Numerical Aperture of Objectives for Dark-field Studies. (D, D, D, Removable Diaphragms.) purchased. Diaphragms for use with objectives in dark-field studies are generally supplied by the manufacturers of reflecting condensers for introduction into the special objectives to be used. These funnel-like diaphragms are not interchangeable and can be employed only for the objectives for which they are designed. Figs. 16, 17 and 18 show three different types and forms of dia- phragms employed for this purpose. In the
RMT0D17K–Electron microscopy; proceedings of the Electron microscopy; proceedings of the Stockholm Conference, September, 1956 electronmicrosco00euro Year: 1957 Fig. I. Ray diagram illustrating the principle of the dark- field system. At the right is shown the special annular aper- ture. are collected with a thermal precipitator directly on beryllium films about 30 A thick. After collection they are heated to 550 C to remove organic matter and condensed oil vapour. At the same time the beryllium oxidizes to form a crystalline oxide film, the diffraction pattern of which is used to calibrate the diffra
RMRD1GPW–. Elementary chemical microscopy. Microscopy; Microchemistry. 40 ELEMENTARY CHEMICAL MICROSCOPY tive. Only those rays included in a low numerical aperture are available. Hence the employment of an objective of high numerical aperture and very short working distance yields a field which is never dark. Since practically all high-power immersion objectives are made with as high numerical apertures as possible, it is absolutely essential that some means be used to reduce their numerical aperture below i, if they are to be employed in dark-field studies. This is accomplished by introducing into the
