OK, so after a few false starts here is what I would suggest, which works pretty well.
In your camera properties, link the X and Y position values to the Z position, making sure to set the scale paramters of the link behaviors to .414. Note that you won’t be able to see that your’e entered this value as the display only allows for two decimal places of accuracy, but you will find that you can actually enter these more precise numbers.
Now when you animate the Z position of the camera, the bottom left hand corner of your scene will stay locked to the bottom left hand corner of the frame. The scale offset takes care of keeping everything in position.
Note that this is assuming a 45 degree angle of view for the camera – different values will require different scale offsets to keep the same result. I’m not entirely sure what the maths is here so you’ll need to experiment – but the principle works.
If you want to animate the camera in the X and Y axes as well, you obviously can’t now do this directly because these position values are linked to the Z position, but it should be OK to put the camera in a group and then animate the position of the group.
Simon Ubsdell
http://www.tokyo-uk.com