I've just replaced an old BenQ projector with an Optoma HD23. I've had to mount the Optoma about four feet closer to the screen to fill it. The Optoma has very limited zoom compared to the BenQ. Also with the BenQ 16:9 images and 4:3 images would both fill the screen widthways. With the Optoma it seems to be the depth rather than the width that stays constant. This means that a 4:3 image sits small in the centre of he screen and I can't even zoom to fill it. Is this normal or have I got some setup wrong?