Chromatic Aberration — usually associated with objective lenses of refractor telescopes, is the failure of a lens to bring light of different wavelengths (colors) to a common focus.
色差-经常在折射望远镜的物镜上出现，是因为透镜不能把不同波长(颜色)的光聚焦到一点而形成的。
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Spherical Aberration — causes light rays passing through a lens (or reflected from a mirror) at different distances from the optical center to come to focus at different points on the axis.
球差-使以不同孔径角穿过透镜(或从镜面上发射)的光线不能聚焦在轴上的同一点。
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This phenomenon is called a chromatic aberration; another example of this effect is seeing a rainbow when you shine white light through a prism.