I currently have a G6 with a Canon 420EX flash and Gary Fong light diffuser. Since the G6 lacks a sync outlet to fire remote flashes, I use the following for group photography: 2 Vivitar 285HV flash units and Photogenic xsmall litedome softboxes on light stands that are fired from a WEIN digital slave module (that bypasses the G6 pre-flash and fires on the actual flash from the 420EX). The flash units are connected by a sync cord to the Wein slave.
One day, I would like to make a low cost portable portrait setup with a backdrop on a x-bar stand. To do this, I will need a way to illuminate the background. What is the least cost way to do this? The Photogenic modelling light/slave seems great but is VERY expensive.
Thanks.

