3DS – Camera move
Paul, I think what you're dealing with is how the camera will automatically
rotate when it's at 90-degrees vertical in the universe. It rotates to
solve the age-old problem of "gimble lock" when completely vertical, and is
one of the major "features" of quaternion rotations (believe it or not).
I've got two suggestions for you. The first one is to never go completely
vertical in your scene. Always undershoot or overshoot the 100% vertical
axis a bit with the camera. The second one is to make a dummy object at
the target position and link the camera to the dummy. You can then rotate
the dummy and control camera rotation more precisely to get the effect you
want. Give them a shot…
– G