Unfortunately there are many modern cameras without hotshoe. And then maybe you have an old flash from analog times and it can not fix. Since the Hama Slave unit is just right. You can attach it to a rail side of the camera and then connect the "old flash" it. Dissolve now the camera flash off, the external flash via a sensor is triggered almost simultaneously with. The camera's automatic and automatic external flash control of the amount of light. Anyone who wants can naturally attach the external flash in the studio and laterally on a tripod. The range between flash trigger sensor and trigger lightning is 10 meters.
But beware: This method does not seem to be working at Canon flashes and cameras with pre-flash, which can not be switched off are not suitable.
Good experience I did with an old Nikon flash SB-24.
