Professional actors have no trouble looking right into the camera as they talk.
But for regular people, the inscrutable black abyss behind the lens is disconcerting.
Which makes it a tough technique to pull off when you want to shoot real people talking without a script.
Unless you have an interitron.
With this device the talent looks straight into the camera but instead of the black hole they see the director's face on a live video feed. It's like a teleprompter but with a human being instead of the scrolling words.
Talking to the camera becomes as natural as talking to another person, and the effect of the interviewee's eye contact is stunning.
Legendary documentary filmmaker Errol Morris is credited with inventing the first interitron setup. Now there are several equipment manufacturers with various designs for this device, which all basically do the same thing.
We used an interitron most recently a Google video on how kids use their cell phones.