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  2. Numerical aperture - Wikipedia

    en.wikipedia.org/wiki/Numerical_aperture

    A lens with a larger numerical aperture will be able to visualize finer details than a lens with a smaller numerical aperture. Assuming quality (diffraction-limited) optics, lenses with larger numerical apertures collect more light and will generally provide a brighter image, but will provide shallower depth of field.

  3. Magnification - Wikipedia

    en.wikipedia.org/wiki/Magnification

    Optical magnification is the ratio between the apparent size of an object (or its size in an image) and its true size, and thus it is a dimensionless number. Optical magnification is sometimes referred to as "power" (for example "10× power"), although this can lead to confusion with optical power.

  4. f-number - Wikipedia

    en.wikipedia.org/wiki/F-number

    For example, if a lens's focal length were 100 mm and its entrance pupil's diameter were 50 mm, the f-number would be 2. This would be expressed as " f /2 " in a lens system. The aperture diameter would be equal to f/2. Camera lenses often include an adjustable diaphragm, which changes the size of the aperture stop and thus the entrance pupil ...

  5. Cardinal point (optics) - Wikipedia

    en.wikipedia.org/wiki/Cardinal_point_(optics)

    For a single lens surrounded by a medium of refractive index n = 1, the locations of the principal points H and H ′ with respect to the respective lens vertices are given by the formulas = ′ = (), where f is the focal length of the lens, d is its thickness, and r 1 and r 2 are the radii of curvature of its surfaces. Positive signs indicate ...

  6. Optical microscope - Wikipedia

    en.wikipedia.org/wiki/Optical_microscope

    A simple microscope uses a lens or set of lenses to enlarge an object through angular magnification alone, giving the viewer an erect enlarged virtual image. [1] [2] The use of a single convex lens or groups of lenses are found in simple magnification devices such as the magnifying glass, loupes, and eyepieces for telescopes and microscopes.

  7. Lens - Wikipedia

    en.wikipedia.org/wiki/Lens

    A burning apparatus consisting of two biconvex lens. A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction.A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (elements), usually arranged along a common axis.

  8. Abbe sine condition - Wikipedia

    en.wikipedia.org/wiki/Abbe_sine_condition

    When the imaging system obeys the Abbe sine condition, the ratio of the sines of these angles equal the (lateral absolute) magnification of the system. In optics , the Abbe sine condition is a condition that must be fulfilled by a lens or other optical system in order for it to produce sharp images of off-axis as well as on-axis objects.

  9. Optical power - Wikipedia

    en.wikipedia.org/wiki/Optical_power

    Converging lenses have positive optical power, while diverging lenses have negative power. When a lens is immersed in a refractive medium, its optical power and focal length change. For two or more thin lenses close together, the optical power of the combined lenses is approximately equal to the sum of the optical powers of each lens: P = P 1 ...