long exposure has been a well known special effect of classic photography. you would typically place your camera on a tripod at night and shoot the stars or the car traffic with several seconds of exposure or “B“ — which would depict the stars in the sky as curved lines. you could not perform long exposures during daytime because that would allow too much light entering the lens, even with a tiny aperture. the neutral-density (ND) filters which throttle the light-input are no real solution.

with the advent of special effects in smartphone photography this night effect was transported into daytime. here is an example, just for demonstration purposes. the image at the top is such a long exposure photo, shot with the google pixel 6. no tripod, no long wait. a matter of maybe 3 seconds, holding the phone in a more or less steady position. the camera delivers two photos. below you see the “original“ — or let‘s call it the classic shot.