A standard lens is a combination of spherical lens elements. Spherical element has a flat shape on the surface of the lens. There is a slight problem when light enters through the lens, there is little difference between the middle of the lens and focus the lens edge. This is called spherical aberration. More and more spherical element means the smaller the risk ternyanya spherical aberration on the optic.
Wide-angle zoom lens and wide-angle lens with wide apertures are very prone to spherical aberration.
To reduce this problem, Tokina makes aspherical element. Aspherical surface element has a proper focus for both the middle and the edge of the lens. Also fix the amount of light entering the edge of the section and distortion.
Tokina Aspherical Glass is the result of collaboration with Hoya Corperation.
When standard optical glass is used for telephoto lens, a phenomenon that commonly occurs is chromatic aberration aberration.Chromatic is a tendency to dispersion of the lens for a ray of light into the colors of the rainbow. Rainbow effect is a dramatic example of the prism, in which incoming light is dispersed into the colors of the rainbow. This will cause the colors are less focused, often referred to as "optical noise" that makes the picture becomes less. To reduce the problem of chromatic aberration, Tokina makes an expensive special lens material with super low ability dispersio (SD)
Tokina SD lens with a code using a lens technology that will reduce the problem of chromatic aberration and optical noise.
Wide-angle lens and zoom from Tokina standard features High and Low Dispersion refraction. With a refractive index of high index and low dispersion properties, this lens will reduce the problem of lateral chromatic aberration, which is common in conventional wide-angle lens.
Reflections on the surface of the lens is a serious problem. Tokina has made the technique on each lens coating to prevent this problem. So that the images will produce the appropriate color and image clarity.
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