In this little flash trigger the desired flash is simply plugged into the hotshoe and can then be ignited by light pulse. Of course, the flash must be previously configured manually. The adapter does not require batteries and triggering worked so far very reliable. Also, with the built-in flash of my compact camera is no problem. I use it to provide products eg. To be able to expose a little better for eBay, but only in private and not professional. It is practical, because small, light and the flash can be placed anywhere realtiv. The sensor must also not pointed directly at the master flash, often it will come as well. I use it with my old Minolta 4000AF program and am very satisfied. The solution may nciht be as flexible as radio, but it is also much cheaper and thus exactly what I was looking for.
