I have a question about the wireless remote control for the D40 (ML-L3). I take it that since it is an accessory item, it should trigger all of the compatible cameras which are in range and expecting the signal? I suppose I have to test it at a store to be sure. I am building a minimum cost stereo photogrammetry setup and am trying to be sure they can be fired simultaneously ... so that I can have one of the cameras fire its flash, and the other camera would just have its shutter conveniently open when the flash comes. I guess I could use a little longer exposure time just to be sure that the flash is seen by both cameras. I think I need to use a flash which is operated in a non-i-TTL mode. If the first camera fires the preflashes (i-TTL), this would mean that the second camera takes its picture before the flash is "properly" fired.