Well, have you ever been a passenger in a car and while riding along you felt total boredom. Yep, recently that happened to me. So I grabbed my Nikon D500, rolled down the window and started shooting at various shutter speeds. The slower the shutter speed the more sense of movement is shown in the photo. Yet when the shadow of your car is captured in the photo it is relatively sharp in comparison to the rest of the photo. This is panning in reverse instead of moving the camera, your camera is still yet moving at the same speed as the car. You can create a lot of cool effects doing this.
Both the photo above and below where taken from a moving car with the camera’s shutter speed at 1/8 of a second. The car was moving much faster in the black and white photo in comparison to the color photo. Give it a try sometime, it is fun.