Hi Don I will try and buy the remote flash sensor over the weekend (if the shop have managed to get some in) then I will try some more shots using the sound trigger and bulb (I might try bulb hitting the ground).
By the way I have been given about 5 used disposable cameras, I might see if I can use the flash's out of them (some how wiring them together with a battery) to make some sort of ring flash
any ideas on how to get them to fire? maybe using the same remote flash trigger unit?