Modeling flash enables you to see the shadow effects on the subject and the lighting balance. You can use modeling flash with a master flash unit or Speedlite Transmitter (sold separately) attached to the camera. Modeling flash can be used for wireless flash shooting as well as normal flash shooting.
Separately control flash compensation for off-camera Speedlites and the built-in flash Setting up an EOS 7D, 60D, or Rebel T3i (600D) to control one or more wireless Speedlites involves two basic steps: 1. Set up the camera for Integrated Speedlite Transmitter operation. 2. Set up the off-camera Speedlite(s) for wireless control.