07-27-2021 10:04 PM
If you have a Canon speedlite or compatible, you can use it to trigger the optical slave built into the strobe. (I am assuming Alien Bee's have an optical trigger built in that allows them to fire based upon another flash firing and triggering them)
07-27-2021 10:44 PM - edited 07-27-2021 10:44 PM
Can you set the pop up internal T7 flash for manual mode so that it won't always do a pre-flash for the E-TTL system? That exposure check flash would trigger the slaves before the regular full flash. With the Speedlites in manual mode, you don't have the problem with the pre-flash triggering the slaves.