hi krissy, to get the best quality pic try setting your camera to no flash mode this is on the top round dial, then if you can slow the aperture speed down and raise the iso to 400. lava might look a bit blurry because the shutter will be open longer as the lava movse. use a tripod and taken the next pic with flash on, use the clone tool in photo shop or photo editing software and copy the lava from the flash shot into the first pic. photo should look great. hope this helps. chris
Also you should use a camera with an IR filter in its lens, which most compacts and cell phone cameras do not have, and their sensors pick up IR light (try taking a shot of a remote control's IR led while in use).
For lava lamps this often means that you will get washed out colors and visible IR light e.g. black wax will appear a washed out puple instead of black. This can be limited by using plenty of external light or a strobe light, though.