I'm preparing to do a very lightweight photo shoot with two speedlights inside 24" softboxes. These particular softboxes have the speedlight completely contained inside the softbox.
I have one speedlight that will be directly connected via 1/8" cable to my camera hot shoe. Will the sensor on the speedlight in the other softbox be able to pick up that flash through its optical slave and fire, or do I need to get some remote triggers for both lights?