How do I interprete Camera extrinsic parameters?

As per this link, the extrinsic parameters consist of a rotation, R, and a translation, t. The origin of the camera’s coordinate system is at its optical center and its x- and y-axis define the image plane.

However when I tried this example. The Z value of translation matrix 't' and Z value of 'cameraLocation' don't match.

Are they not the same? If not how do we define cameraLocation?

Answer 1

[Matt J]

cameraLocation = -camExtrinsics.Translation/camExtrinsics.R;

or in other words if , the optical center is at .