Off-camera slave triggered by built-in as wireless (with Pentax K-30)

About the issue

It seems that, although the Bower SFD926 flash works flawlessly as an on-camera flash, when using it off-camera in slave mode, and combined with the on-camera (perhaps built-in) flash in wireless mode (either master or controller) or in automatic mode, it fails to trigger the slave flash if set to high power (perhaps higher than 1/4).

The issue is that the on-camera flash emits a pre-exposure pulse, which the slave flash (Bower in this case) assumes is the trigger and outputs the burst of light. However moments later, during the actual exposure, the on-camera flash emits another pulse that should be the actual trigger; unfortunately if the slave flash (Bower) is set to a high power (perhaps higher than 1/4), it will not have enough power to output another burst of light.


The only solution (without involving extra hardware) is to either:

By using additional hardware, one can either: