External Orientation Calibration

There are several instances in which the use of the External Orientation Calibration can be helpful:

1. Large measurement fields for which a large enough grid is not practical.

2. The cameras have been moved or bumped since calibration, giving you a higher than expected projection error

3. Test setups that include nonstandard distortions, such as from a glass pane or viewing window

The linked document explains the different procedures for using this feature for all of the above instances.