Normally, light moves so fast that it seemingly instantly jumps from point A to point B, or at least faster than the eye can follow. Not when this trope comes into action. In this case, you can see light bounce all over the place (evidently viewed by photons traveling at normal speed) instead of instantly seeing the new setup.
When applied to beam/laser weapons, may overlap with Painfully Slow Projectile and/or Slow Laser, depending on just how slow the light goes.
Sometimes done for effect in Bullet Time, or to establish causality for the viewer's convenience. Can be used to show off a Light and Mirrors Puzzle
Examples:
- At the conclusion of Legend (1985), the sunlight takes 20 seconds to reflect off all of the shields and reach the underground chamber where it blows away Darkness.
- Blade II has technology that can make light move at different speeds, with really slow flash-grenades and regular full spectrum flashlights.
- Over the Hedge: Towards the climax of the movie, Hammy the squirrel downs an energy drink. His regular speed is already something like a Flash Step, on caffeine he's able to
leisurely out-stroll lasers.
- Light actually works this way in-universe in the Discworld. It's explained that this is because of the Disc's strong magical field distorting the way physical law works, slowing down light to roughly the speed of sound. In an extreme case, we find out that the Disc's sunnote actually travels at twice the speed of its own light ("this does not appear to cause any problems"). Indeed, we find that an observer will start seeing a relativistic red/blue frequency shift while travelling in a magically enhanced coach at the unprecedented speed of 40 miles an hour.
- Hyperion Cantos: In Kassad's tale, both he and the Shrike attack an Ouster military camp. The Shrike slows time enough so that Kassad can literally dodge a laser beam.
- Bones: When Zack shows Booth & Brennan a mirror setup that the Gormagon used to watch the vault, he sets off a laser beam that works its way very slowly around the room.
- Dungeons & Dragons module T1-4 The Temple of Elemental Evil. When the PCs confront Zuggtmoy in her lair she activates a Prismatic Spray-type device that causes beams of light to spring forth and visibly bounce off things.
- In one Scooby-Doo episode, the gang gets locked in an ancient temple. To get out, they need to reflect moonlight onto a symbol on the wall a la Light and Mirrors Puzzle. However, instead of the light instantly appearing on the wall, we see a ray of light slowly bouncing between the mirrors until it reaches the wall. Worse yet, it misses at first, forcing Scooby to readjust just in time for another pulse of light to slowly move in and be reflected.
- Acknowledged in the epilogue of one episode of The Magic School Bus involving a light-based pinball-like game.
- Femto Fotography, recording light at a pace of 0.6mm.
