Are the SMALL TUBELIKE "cameras" usually placed next to the traffic light cameras used to drivers' photos?

I am talking about the camera that are usually placed NEXT to the traffic lights that look like a small short tube. are those cameras or just sensory devices? i kinda ran a red light but it only turned red for 1 second after it was yellow. what are the functions of these cameras?Are the SMALL TUBELIKE "cameras" usually placed next to the traffic light cameras used to drivers' photos?
they could be a camera or a sensor if you were caught with a camera you would have most likely seen a flash. The tubes where I am from are for sensors for emergency equipment. they have them on the turn lanes and the straight through lanes. Also here the camera has to have signage "red light camera in use ticket enforced" Kind of neat that way you know where they are at.