How can I key out the background in a photograph?

Episode 1366 (16:32)

Joe from Wikiwatchi, FL
Green screen

Joe is a photographer and he wants to be able to key out the background and replace it. He wants to be able to do this in real time so he can show the client the photo with the keyed background. Leo says the first step is to tether the camera to a laptop so it'll show the image on a screen right away. That means he'll be adding a radio transmitter or something to his camera and a receiver on the laptop. Then he'll need software like Lightroom that could do this.

Someone in the chatroom said they use Capture One Pro for tethering. Leo says many photographer supply stores have all-in-one kits for this as well.

Image By Jared Tarbell from Albuquerque, United States of America (green room) [CC BY 2.0], via Wikimedia Commons