Collimated light

The collimation (Latin colli mare, modified by collinear "to lead in a straight line " ) refers to the direction parallel optics of light rays. The associated lens is called a collimator.

A so-called auto-collimation occurs when behind the collimator is a mirror and the light rays are reflected through the same lens. The image remains sharp even when the position of the mirror is moved. The collimation is determined by the cross hair sight and Absehlinie of the telescope.

In metrology collimation means that the real value of a measured variable with the read from the meter setting matches exactly. Is not present this correspondence, the instrument with a collimation is affected, which in size and location to be determined by exactly, so you can set it for each individual measurement in accounting or eliminated.