In this video Rob shows us how to perform the field collimations for the SX10 camera. These collimations are to adjust the telecamera auto focus and the automatic camera calibration.
The telecamera auto focus adjustment ensures that when the camera focuses on an object, that the object is indeed in focus. This adjustment only needs to be done if you notice that the camera looks fuzzy or is not properly focusing on objects. It also checks/adjusts the focus for Face 1 and Face 2.
The automatic camera calibration corrects for errors between Face 1 and Face 2 for the Overview, Primary or Telecamera. Angles observed in a single face are corrected for collimation errors, which eliminates the need to measure in both instrument faces.