The sensor for movement is usually pointed at the white line at the entrance of the intersection, so that the first picture is a wide angle shot of you entering the intersection while the light is red (ie, it won\'t take a photo if the light was yellow when you entered the intersection), and the second photo is generally a slightly closer picture but with frame of reference from the first photo, so that they can determine both your licence plate and speed from the second (ie, .2 seconds apart, they can show how fast you were moving by distance travelled). Every light camera here is set up that way.