collimating
 准直
 Col·li·mate v. t. [imp. & p. p. Collimated; p. p. & vb. n. Collimating.]  Physics & Astron. To render parallel to a certain line or direction; to bring into the same line, as the axes of telescopes, etc.; to render parallel, as rays of light.
 Collimating eyepiece, an eyepiece with a diagonal reflector for illumination, used to determine the error of collimation in a transit instrument by observing the image of a cross wire reflected from mercury, and comparing its position in the field with that of the same wire seen directly.
 Collimating lens Optics, a lens used for producing parallel rays of light.
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