Incandescent bulbs have a steady glow. When at night you're behind cars with incandescent taillights and you make your eyes scan quickly from one side to the other, the taillights will appear to leave a solid streak in your field of vision.
I've noticed that there are certain makes of cars with LED taillights where a quick eye-scan from side to side creates a sort of "stutter trail" of widely-spaced red dots instead of a streak. This is obviously due to the fact that LEDs pulse on and off in operation.
But what I don't understand is why it's only certain models that do this. I've noticed the "stutter" with Cadillacs, Lincolns, Nissans and VWs, but not with Hondas/Acuras and BMWs. Honda and BMW LED taillight design makes a nearly solid streak on a quick eye scan.
Anybody know why the difference?