I'll go into a little more detail to explain exactly what I'm trying to achieve.
Firstly, the camera that I mention is actually a real camera (A canon G9 camera that I'm operating remotely)
I know the focal length of the camera so basically I can work out the perspective matrix of the camera (theres also
a bit of lens distortion but its not too bad).
The camera is located anywhere in the room but is always facing the inside of a sphere. My problem is that I need
to calculate the location of the camera in relation to the centre of the sphere.
In order to calculate this I figure that I need to physically mark three arbitary points on the inside of
the sphere that the camera can see. I can measure the XYZ locations of each of these points relative
to spheres centre.
The resulting camera position would be a best-fit solution.