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Oil immersion objective lenses look superficially identical to non-oil immersion lenses. In light microscopy, oil immersion is a technique used to increase the resolving power of a microscope. This is achieved by immersing both the objective lens and the specimen in a transparent oil of high refractive index, thereby increasing the numerical ...
Two Leica oil immersion microscope objective lenses; left 100×, right 40×. The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes ...
Water immersion objectives are used not only at very large magnifications that require high resolving power, but also of moderate power as there are water immersion objectives as low as 4X. Objectives with high power magnification have short focal lengths, facilitating the use of water. The water is applied to the specimen (conventional ...
The refractive index of the index-matching material is higher than air allowing the objective lens to have a larger numerical aperture (greater than 1) so that the light is transmitted from the specimen to the outer face of the objective lens with minimal refraction. Numerical apertures as high as 1.6 can be achieved. [26]
The area provides a reference unit, for example in reference ranges for urine tests. [3]Used for grading of soft tissue tumors: Grading, usually on a scale of I to III, is based on the degree of differentiation, the average number of mitoses per high-power field, cellularity, pleomorphism, and an estimate of the extent of necrosis (presumably a reflection of rate of growth).
An optical telescope's ability to resolve small details is directly related to the diameter (or aperture) of its objective (the primary lens or mirror that collects and focuses the light), and its light-gathering power is related to the area of the objective. The larger the objective, the more light the telescope collects and the finer detail ...
A Swift model 687M variable power rifle telescopic sight with parallax compensation (the ring around the objective lens is used for making parallax adjustments). Telescopic sights are classified in terms of the optical magnification (i.e. "power") and the objective lens diameter. For example, "10×50" would denote a fixed magnification factor ...
Binoculars concentrate the light gathered by the objective into a beam, of which the diameter, the exit pupil, is the objective diameter divided by the magnifying power. For maximum effective light-gathering and brightest image, and to maximize the sharpness, [ 27 ] the exit pupil should at least equal the diameter of the pupil of the human eye ...