When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Optical aberration - Wikipedia

    en.wikipedia.org/wiki/Optical_aberration

    The reverse, in which the perimeter is magnified more than the center, is known as "pincushion distortion" (figure 3b). This effect is called lens distortion or image distortion, and there are algorithms to correct it. Systems free of distortion are called orthoscopic (orthos, right, skopein to look) or rectilinear (straight lines). Figure 4

  3. Astigmatism (optical systems) - Wikipedia

    en.wikipedia.org/wiki/Astigmatism_(optical_systems)

    Surface distortion due to grinding or polishing increases with the aspect ratio of the part (diameter to thickness ratio). To a first order, glass strength increases as the cube of the thickness. Thick lenses at 4:1 to 6:1 aspect ratios will flex much less than high aspect ratio parts, such as optical windows, which can have aspect ratios of 15 ...

  4. Distortion (optics) - Wikipedia

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

    In geometric optics, distortion is a deviation from rectilinear projection; a projection in which straight lines in a scene remain straight in an image.It is a form of optical aberration that may be distinguished from other aberrations such as spherical aberration, coma, chromatic aberration, field curvature, and astigmatism in a sense that these impact the image sharpness without changing an ...

  5. Perspective distortion - Wikipedia

    en.wikipedia.org/wiki/Perspective_distortion

    In photography and cinematography, perspective distortion is a warping or transformation of an object and its surrounding area that differs significantly from what the object would look like with a normal focal length, due to the relative scale of nearby and distant features.

  6. Dots per inch - Wikipedia

    en.wikipedia.org/wiki/Dots_per_inch

    As it is, the Macintosh 128K featured a screen measuring 512 pixels in width by 342 pixels in height, and this corresponded to the width of standard office paper (512 px ÷ 72 px/in ≈ 7.1 in, with a 0.7 in margin down each side when assuming 8 + 1 ⁄ 2 in × 11 in North American paper size; in the rest of the world, it is 210 mm × 297 mm ...

  7. Anamorphic format - Wikipedia

    en.wikipedia.org/wiki/Anamorphic_format

    One common misconception about the anamorphic format concerns the actual width number of the aspect ratio, as 2.35, 2.39 or 2.40. Since the anamorphic lenses in virtually all 35 mm anamorphic systems provide a 2:1 squeeze, one would logically conclude that a 1.375∶1 full academy gate would lead to a 2.75∶1 aspect ratio when used with ...

  8. Fisheye lens - Wikipedia

    en.wikipedia.org/wiki/Fisheye_lens

    A fisheye lens is an ultra wide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. [4] [5]: 145 Fisheye lenses achieve extremely wide angles of view, well beyond any rectilinear lens.

  9. Atmospheric refraction - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_refraction

    Diagram showing displacement of the Sun's image at sunrise and sunset Comparison of inferior and superior mirages due to differing air refractive indices, n. Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. [1]