2.1 Choosing cameras

When two or more cameras arranged in stereo are calibrated (using either photographs or video), the resulting calibration is specific to that particular arrangement of the cameras (their position and orientation). The cameras can move if they are rigidly attached to some support system and the support system itself is moved. However, the relative position and orientation of the cameras relative to one another must remain fixed to collect accurate 3D data. Additionally, the calibration is specific to the particular zoom and focus, so these must also remain fixed.

Keeping the cameras immobile and maintaining the same zoom and focus necessitates a few key technical specifications:

• A remote trigger mechanism (since touching the shutter button repeatedly causes the camera to move)
• Manual focus mode (i.e. ability to turn off auto-focus)
• Manual zoom mode (i.e. ability to turn off auto-zoom)