I currently have two Canon Speedlite 430EX Flashes and plan to get the Canon Speedlite Transmitter ST-E2 to control them. I notice in the review the ST-E2 is described as a small and light Canon wireless slave flash controller and focus assist device.
Does this mean it can be used as a focus assist independent of flash use? Like for instance could I use it to speed up the focusing of my Canon EF 50mm f/1.8 II when a flash is not appropriate?
For that matter could a Canon Speedlite 430EX be used in such a manneras a focusassist device but not flash?