You can make points infinite or locked in the Locator Summary panel. These designators are another way to help the solver, like survey constraints.
To make a point infinite or locked, simply click next to the locator in the Locator Summary panel. To return a point to normal, click the icon again. See the following illustration.
Tells the solver to treat the point as infinitely far from the camera, such as a cloud, mountain, or any feature in the distant background. Knowing a point is infinite, the solver can use it exclusively for calculating camera movement. It does not need to determine the point’s position in space, so the locator becomes hidden.
By making two or more points infinite, you can significantly help the solver calculate zoom shots, provided those points are visible long enough.
Locks the locator point to a specific 3D location. A locked point is exactly like assigning it to a survey Point constraint, but the workflow is easier. Simply click the lock icon and move or snap the locator to a given position. However, Point constraints are still required if you want it to be used for registration only.
