3D rig

A 3D rig is a device for mounting two cameras together to one 3D-system in order to shoot stereoscopic films and images.

To create stereoscopic depth illusion in movie or photography, two slightly different images have to be viewed at the same time, each of them presented to one eye.

In addition to that the cameras have to be geometrically aligned accurately, to minimize the amount of stereoscopic errors.

A side-by-side rig is a proper way to do wide shots like landscape or overviews in sport broadcasting, however they cannot be used for close-ups since the minimum distance between the cameras is limited to the size of the lenses.

[5] They also often provide bigger possible interaxial distances then mirror rigs, which can be used to create a miniaturization effect.

This can throw the system's weight out of balance, which can cause problems when used on a camera stabilization mount (e.g. Steadicam).

Mirror rigs make telling stories with classical tools of film narration possible.

[7] To simply zoom in or use long lenses to get close-up shots with a side-by-side rig leads to a bad roundness.

[8] Another advantage is, that the images can be used for the geometrical alignment of the cameras since stereoscopic errors can be seen most easily when the interaxial distance is zero.