Whether it is answering your complex technical questions, or even just having a friendly conversation, we treat you the way you want to be treated. An optical schematic illustrating the basics of autocollimation is shown in Figure 1 below. The system begins with a light source followed by condensing lenses and a projection reticle. The condensing lenses are used to maximize both the intensity and uniformity of the light directed through the projection reticle in focal plane P 1 . After passing through the beamsplitter, light enters the objective lens where it is collimated prior to exiting the instrument.
Collimation simply means that the light rays exit the instrument parallel to one another.
The return image appears in sharp focus on the measuring reticle in focal plan P 2 after being redirected 90 by the beamsplitter. An eyepiece is used to view the return image. Deviation of the mirror by an amount A as shown in the figure will cause the return image to be laterally displaced in P 2 a distance X with respect to the measuring reticle. In this equation, f L , is a constant equal to the focal length of the objective lens. From the equation it is apparent that X is independent of the distance between the instrument and the reflecting surface.