I need some digital help! I have a Nikon Coolpix 8700. There is a certain picture I wish to capture, and as yet I have had no luck. The setting is this: Where I go to school, the foyer is made of marble, and is mostly glass enclosed. So in the cooler parts of the year, ( or in early morning), the space heaters turn on autimatically. They are in the floor, so the heat will rise. When the sun hits the foyer at the correct angle, you can see the heat waves rising along the base of the walls. Try as I might, I cannot capture those heat waves -- all I get is a great looking exposure of a marble wall! Should I even be using digital, or should I switch to SLR for this type of photography?