A method for adjusting a power relation between several remote flash devices using TTL and an intermediate radio transmission unit for wireless transmission of radio signals to the remote flash devices and for bi-directionally exchanging signals with the camera via a physical connection between the intermediate radio transmission unit and the camera, the method comprising the steps of: receiving information or setting in the respective remote flash devices about the amount of power that the remote flash devices should use for their respective preflashes; transmitting from the camera to the intermediate radio transmission unit a preflash activation signal; emitting at the same point in time from the respective remote flash devices preflashes with a power relation according to the received information or settings in the remote flash devices; initiating in the camera a preflash image analysis; determining in the camera in dependence on the preflash image analysis one amplification to be applied during subsequent main flashes from the different remote flash devices, wherein the camera is determining the amplification to be applied during the subsequent main flashes from the different remote flashes based on the different amount of power in the preflashes from the respective remote flash devices; transmitting, from the camera via the intermediate radio transmission unit to the remote flash devices, the amplification for the remote flash devices to apply during the main flashes; transmitting, from the camera via the intermediate radio transmission unit to the remote flash devices, a main flash activation signal; and emitting at the same point in time from the respective remote flash devices main flashes while applying in the remote flash devices the amplification, determined in the camera, to the power for the respective preflashes, such that the power relation for the main flashes corresponds to the power relation for the preflashes. receiving information or setting in the respective remote flash devices about the amount of power that the remote flash devices should use for their respective preflashes; transmitting from the camera to the intermediate radio transmission unit a preflash activation signal; emitting at the same point in time from the respective remote flash devices preflashes with a power relation according to the received information or settings in the remote flash devices; initiating in the camera a preflash image analysis; determining in the camera in dependence on the preflash image analysis one amplification to be applied during subsequent main flashes from the different remote flash devices, wherein the camera is determining the amplification to be applied during the subsequent main flashes from the different remote flashes based on the different amount of power in the preflashes from the respective remote flash devices; transmitting, from the camera via the intermediate radio transmission unit to the remote flash devices, the amplification for the remote flash devices to apply during the main flashes; transmitting, from the camera via the intermediate radio transmission unit to the remote flash devices, a main flash activation signal; and emitting at the same point in time from the respective remote flash devices main flashes while applying in the remote flash devices the amplification, determined in the camera, to the power for the respective preflashes, such that the power relation for the main flashes corresponds to the power relation for the preflashes.