Is there a sensor to track a Person as they move around a room?

Query by Tim R: Is there a sensor to track a Man or woman as they move close to a room?
Seeking for a sensor that will track a man or woman in buy to make a easy point like a light or video digital camera comply with that man or woman. I have believed of motion sensors, possibly two in conjunction, and many others. What else is there for this? Would be preferable if it ended up affordable. Thank you


Best reply:

Remedy by norafarawi
infrared? have a spy:P

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