Floodlight must be close to activate lights

I've turn my flood light to the maximum distance and increase the sensitivity of the camera. I have no issues with the camera activating and catching everything that drives down the street. My issues is you have to walk all the way up to about 5-10 feet of the garage for the motion lights to turn on. If someone wanted to break into a vehicle at the end of the driveway they wouldn't turn on. It's only a 2 car lengths long. The camera is mounted about 15ft high. Is my light zone defective?