I'm going to mount my projector on the ceiling next week and I wondered if there was a clever way to work out how long a pole I need to order. The ceilings in our house are very high and a normal length mount won't do it, so I'm going to order one with an extension pole. The thing is, I know the projector will be mounted upside-down, but does that affect the way the image is projected? How do I work out how high (or low) I need to mount the projector? Any help would be appreciated.