your word for today is...
ABERRATION (ab-er-ay-shun)
(1) Something that prevents light from being brought into sharp focus, dis-enabling the formation of a clear image.
(2) Lens flaw - the inability of a lens to reproduce an accurate, focused, sharp image. Aberration in simple lenses is sub-categorized into seven types:
Astigmatism - lines in some directions are focused less sharply than lines in other directions, Chromatic aberration or Axial chromatic aberration - different wavelengths of light coming into focus in front of and behind the film plane, resulting in points of light exhibiting a rainbow-like halo and reduction in sharpness, Coma - the image of a point source of light cannot be brought into focus, but has instead a comet shape, Curvilinear distortion - distortion consisting of curved lines, Field curvature - the image is incorrectly curved, Lateral chromatic aberration also known as Transverse chromatic aberration - variation in the magnification at the sides of a lens (this aberration type used to be termed “lateral color”), Spherical aberration - variation in focal length of a lens from center to edge due to its spherical shape - generally all parts of the image, including its center |
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