Quote - IMO, all wrong answers.

Assuming you used the main camera first, parent the dolly camera to the main, six inches away. The dolly camera will be lock stepped to whatever you did to the first camera. Use the dolly camera for your other "eye".

You can also make a new camera for this purpose if you like - but the idea is the same. When you want one object to stay in specific position relative to another, you parent one to the other.

That would be the easiest thing, i think. But the problem here is that Mike wants his camera not only to move around, but also to zoom. I tried to bind the focal length of one camera to the other camera with dependent parameters, but for some reason it does not work (with Poser8); the cameras seem to completely evade the grasp from the dependent parameter's force (for both driving and receiving them). I did not try with the deltaAddDelta thing in the pz3 file though. Also, the dependent parameters might work in Poser2012, if so, it would be a very elegant solution.