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  2. Parfocal lens - Wikipedia

    en.wikipedia.org/wiki/Parfocal_lens

    Zoom lenses (sometimes referred to as "true" zoom) are ideally parfocal, in that focus is maintained as the lens is zoomed (i.e., focal length and magnification changed), which is convenient and has the advantage of allowing more accurate focusing at maximal focal length then zooming back to a shorter focal length to compose the image. [1]

  3. Bright-field microscopy - Wikipedia

    en.wikipedia.org/wiki/Bright-field_microscopy

    A bright-field microscope has many important parts including; the condenser, the objective lens, the ocular lens, the diaphragm, and the aperture. Some other pieces of the microscope that are commonly known are the arm, the head, the illuminator, the base, the stage, the adjusters, and the brightness adjuster.

  4. Optical microscope - Wikipedia

    en.wikipedia.org/wiki/Optical_microscope

    The optical microscope, also referred to as a light microscope, is a type of microscope that commonly uses visible light and a system of lenses to generate magnified images of small objects. Optical microscopes are the oldest design of microscope and were possibly invented in their present compound form in the 17th century.

  5. Microscopy - Wikipedia

    en.wikipedia.org/wiki/Microscopy

    Antonie van Leeuwenhoek (1632–1723). The field of microscopy (optical microscopy) dates back to at least the 17th-century.Earlier microscopes, single lens magnifying glasses with limited magnification, date at least as far back as the wide spread use of lenses in eyeglasses in the 13th century [2] but more advanced compound microscopes first appeared in Europe around 1620 [3] [4] The ...

  6. Zoom lens - Wikipedia

    en.wikipedia.org/wiki/Zoom_lens

    Many so-called "zoom" lenses, particularly in the case of fixed-lens cameras, are actually varifocal lenses, which gives lens designers more flexibility in optical design trade-offs (focal length range, maximal aperture, size, weight, cost) than true parfocal zoom, and which is practical because of autofocus, and because the camera processor ...

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  8. Millions hurt by credit repair firms to share $1.8 billion in ...

    www.aol.com/millions-hurt-credit-repair-1...

    More than 4 million Americans gouged by credit repair companies including Lexington Law and CreditRepair.com will soon collectively receive $1.8 billion in refund checks, the Consumer Financial ...

  9. Near-field optics - Wikipedia

    en.wikipedia.org/wiki/Near-field_optics

    The limit of optical resolution in a conventional microscope, the so-called diffraction limit, is in the order of half the wavelength of the light used to image.Thus, when imaging at visible wavelengths, the smallest resolvable features are several hundred nanometers in size (although point-like sources, such as quantum dots, can be resolved quite readily).