If there is another Canon wireless flash system nearby, you can change the channel number to prevent signal confusion. the sender and the receiver units must be set to the same channel number.
Manual flash or stroboscopic flash can be set manually with the receiver unit. Do this in the following cases 1. When you want to set the flash output with the receiver units individually for wireless flash as with studio flash units
Remove the contact cover from the side of the flash. Then connect the power cord for the CP-E4 to the flash. This power the is used to recycle the flash faster so be sure to have batteries in the flash as well.
It enables you to see the shadow effect on the subject and the lighting balance. You can fire the modeling flash for wireless and normal flash shooting.