iPhone FaceTime Video Calls

Get some FaceTime Press the FaceTime button,
indicated by the video camera icon, to start your
video chatting session
Conducting webcam-based calls on a laptop or PC is nothing new. FaceTime extends the concept of video chatting to smartphones.

You need a Wi-Fi or 3G cellular network connection and for whoever you’re calling to have a FaceTime compatible device (an iPhone 4/4S or iPhone 5, a 2010 or later iPod touch or a Mac with an iSight camera).

To initiate a FaceTime call, you can make a voice call as usual and then switch over to a video chat by tapping the FaceTime button. This appears where the Hold button usually does during phone calls. (You’ll still see Hold if you have the FaceTime feature disabled, or you can bring it up by pressing and holding the Mute button).

A question mark appears if your iPhone isn’t sure that the other party has FaceTime abilities. If they do, the recipient will be presented with a screen allowing him or her to decide whether to accept your FaceTime request. If they decline, you’ll stay on the phone sans video. If you accept it, FaceTime will launch and both callers will appear onscreen.

FaceTime now works over cellular as well as Wi-Fi, but you may need to turn it on by going to Settings > FaceTime and changing the Use Cellular Data setting to On. Be careful of how much data you are using though.

iPhone FaceTime Video Calls
Source : The Complete Guide to the iPhone 5