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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. Biological specimen - Wikipedia

    en.wikipedia.org/wiki/Biological_specimen

    Biological specimens in an elementary school science lab. A biological specimen (also called a biospecimen) is a biological laboratory specimen held by a biorepository for research. Such a specimen would be taken by sampling so as to be representative of any other specimen taken from the source of the specimen. When biological specimens are ...

  4. History of photographic lens design - Wikipedia

    en.wikipedia.org/wiki/History_of_photographic...

    For example, retrofocus wide angle lenses tend to have excessive spherical aberration [158] and astigmatism at close focusing distances and so the Nikkor-N Auto 24mm f/2.8 (Japan) of 1967 for Nikon 35mm SLRs had a Close Range Correction system with a rear three element cell that moved separately from the main lens to maintain good wide aperture ...

  5. Live-cell imaging - Wikipedia

    en.wikipedia.org/wiki/Live-cell_imaging

    Biological systems exist as a complex interplay of countless cellular components interacting across four dimensions to produce the phenomenon called life. While it is common to reduce living organisms to non-living samples to accommodate traditional static imaging tools, the further the sample deviates from the native conditions, the more likely the delicate processes in question will exhibit ...

  6. Laboratory experiments of speciation - Wikipedia

    en.wikipedia.org/wiki/Laboratory_experiments_of...

    A simplification of an allopatric speciation experiment where two lines of fruit flies are raised on maltose and starch media. Laboratory experiments of speciation have been conducted for all four modes of speciation: allopatric, peripatric, parapatric, and sympatric; and various other processes involving speciation: hybridization, reinforcement, founder effects, among others.

  7. Varifocal lens - Wikipedia

    en.wikipedia.org/wiki/Varifocal_lens

    The change in the subject size is a significant problem in video and true parfocal designs are needed for higher quality video work. Varifocal lenses can be used for image display as well as capture, and Meta's Reality Labs has confirmed developing a varifocal display for virtual reality. [2] A varifocal lens. Left image is at 2.8 mm, in focus.