Hi, all.

In the 1980s I ran my own video production company. Eventually I worked a very short time at a TV station until I got hired at a major airline which was what I really wanted to do. Nonetheless, the experience in TV was and still is, valid and valuable.

I'll make this short. You may have heard of Green Screens or Green Screen TV/Video. Green is the most common color and the color of green used is common to your Microsoft icons on your computer. Think of it as an intense green. Production switchers in television stations/networks/mobile busses, etc look much like audio consoles in recording studios. These production switchers are able to nullify the green and paste any person or object over a background to make it appear that person is in the location of that background. This is called chroma-keying. Seeing Hillary in an airplane hangar for example. The way this is done is to video the main subject with a pure green, blue or red (not ever used but possible) background. Then the switcher "keys" out that background leaving the underlying video track or input from a live camera which essentially puts the subject on location. Many will actually believe that the person such as Hillary Clinton is on location shown.

There are two main ways to notice if chroma-keying is being used when you see a video. The first is to notice any ghosting in material of the dress/suit/object the person is wearing. In such areas the background bleeds through slightly and often has some movement to it. A shimmer if you will. This can often be seen during your local weather forecast. The other giveaway is what might appear only momentarily around the edge of the garment the speaker is wearing. It appears as an almost invisible dotted line especially around the shoulders. Other places on the person can show up also, but that is where they are most likely noticed as the viewer tends to gravitate to the face.

There you go, things you can watch for in videos to decide if they are live or chroma-keyed.

Also, one other technique you might not notice and not technical in nature is how the person is framed in the surrounding shot. What I mean is it takes a sharp eye and some experience, but when no crowd is ever shown in the video it generally means there was not a crowd present. It also alerts the viewer to look hard for the tell-tales just mentioned above. Also, you photographers out there should also be watching for unmatched depth of field to the main subject. The subject seems to appear to be floating in the frame unnaturally. Usually this is hard to spot but go with the feeling that something is not right and it probably isn't. But there is a long explanation just on that.

Now you have more info than you did and can become a chroma key spotting expert quickly.

Gooday all,

CapnGriff