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  2. Esotropia - Wikipedia

    en.wikipedia.org/wiki/Esotropia

    Esotropia is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. [1] It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called ...

  3. Maddox rod - Wikipedia

    en.wikipedia.org/wiki/Maddox_rod

    The strength of the prism is increased until the streak of the light passes through the centre of the prism, as the strength of the prism indicates the amount of deviation present. The Maddox rod is a handheld instrument composed of red parallel plano convex cylinder lens , which refracts light rays so that a point source of light is seen as a ...

  4. Canon FT QL - Wikipedia

    en.wikipedia.org/wiki/Canon_FT_QL

    The Canon FT QL is a 35mm single-lens reflex camera introduced by Canon Inc. in March 1966. It has a Canon FL lens mount compatible with the large range of FL series lenses. The FT can also operate the later Canon FD series lenses in stop-down mode, but the earlier R series has a different lens aperture mechanism and cannot be used, although ...

  5. Single-lens reflex camera - Wikipedia

    en.wikipedia.org/wiki/Single-lens_reflex_camera

    A single-lens reflex camera ( SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final ...

  6. Prism correction - Wikipedia

    en.wikipedia.org/wiki/Prism_correction

    Prism dioptres. Prism correction is commonly specified in prism dioptres, a unit of angular measurement that is loosely related to the dioptre. Prism dioptres are represented by the Greek symbol delta (Δ) in superscript. A prism of power 1 Δ would produce 1 unit of displacement for an object held 100 units from the prism. [2]

  7. Perspective control - Wikipedia

    en.wikipedia.org/wiki/Perspective_control

    Perspective control. Perspective control is a procedure for composing or editing photographs to better conform with the commonly accepted distortions in constructed perspective. The control would: make all lines that are vertical in reality vertical in the image. This includes columns, vertical edges of walls and lampposts. This is a commonly ...

  8. Flat-field correction - Wikipedia

    en.wikipedia.org/wiki/Flat-field_correction

    This variation is called vignetting, and can be corrected by selectively brightening the perimeter of the image. Flat-field correction ( FFC) is a digital imaging technique to mitigate the image detector pixel-to-pixel sensitivity and distortions in the optical path. It is a standard calibration procedure in everything from personal digital ...

  9. Camera lucida - Wikipedia

    en.wikipedia.org/wiki/Camera_lucida

    Camera lucida in use. A camera lucida is an optical device used as a drawing aid by artists and microscopists . The camera lucida projects an optical superimposition of the subject being viewed, onto the surface upon which the artist is drawing. The artist sees both scene and drawing surface simultaneously, as in a photographic double exposure.

  10. Pentamirror - Wikipedia

    en.wikipedia.org/wiki/Pentamirror

    A pentamirror is an optical device used in the viewfinder systems of various single-lens reflex cameras instead of the pentaprism. It is used to reverse again the laterally reversed image coming from the reflex mirror. Instead of the solid block of glass of the prism in pentaprism system, here 3 mirrors are used to perform the same task.

  11. Image geometry correction - Wikipedia

    en.wikipedia.org/wiki/Image_geometry_correction

    Image Geometry Correction (often referred to as Image Warping) is the process of digitally manipulating image data such that the image’s projection precisely matches a specific projection surface or shape. [1] Image geometry correction compensates for the distortion created by off-axis projector or screen placement or non-flat screen surface ...