Fixed camera calibration method

The Fixed camera calibration method uses fixed locations of the cameras and the reference markers to calibrate a camera system. This calibration method is mainly useful for systems covering large areas, where a wand calibration may be difficult or impossible to perform. The fixed calibration type requires that the cameras are at fixed, stable locations.

The fixed camera calibration requires that the exact positions of the cameras and reference markers, obtained from a survey measurement, are entered on the Calibration page in the Project options dialog, see chapter Fixed camera calibration. The fixed calibration than calculates the camera orientations and optimizes the focal lengths for each camera, based on the measured positions of the reference markers.

For more information about how to install and use a fixed camera system, contact Qualisys AB.

Outline of how to calibrate (fixed calibration)

Follow these steps to calibrate the camera system with the fixed calibration method:

  1. Make sure the camera system and the reference markers are switched on.

  2. Make sure that the settings on the Calibration page in the Project options dialog are correct, see chapter Fixed camera calibration.

  3. Make sure that the cameras can see the reference markers as specified in the fixed calibration definition, see chapter Camera locations and markers seen by each camera in order from left to right. If needed, mask any extra reflections.

  4. Start a preview by clicking the New file icon .

  5. Click the Calibration icon  and set the settings in the Calibration dialog, see chapter Calibration dialog.

    There are no restrictions for the frequency or the calibration time for the fixed calibration method. When calibrating at a low capture frequency, QTM may automatically prolong the calibration duration in order to collect the minimum number of required frames.

  6. Click OK to start the calibration.

  7. Check the Calibration results and click OK.