Wet-for-dry is a term in the film industry for a special effect wherein an actor or prop is filmed in a water-filled tank, then imposed onto the film most often via Chroma Key or similar technology. The purpose of this is either to facilitate Slow Motion or to create the image of a supernatural creature not entirely bound by gravity. Filming in water works most effectively on hair and other long, flexible appendages, so expect this effect to take full advantage of such.
The opposite of wet-for-dry is dry-for-wet, where a subject filmed on a stage is imposed onto a water backdrop to avoid having to film underwater, thus making it possible for actors to do a scene while also being able to, for instance, breathe.
Examples of Wet-For-Dry:
- Clouds (by means of dye solutions) were frequently done this way before CGI, though in a sense it's all still wet.
- The dance of the Oracle of Delphi in 300.
- The titular Dogora in Dogora had its alien movements realised by immersing its prop in a tank of water and using a water current to get it to move.
- The zero-gravity space scenes in Guardians of the Galaxy, such as the scene where Peter saves Gamora's life when she is left in space after her space pod explodes, were shot underwater to get the effect of hair flowing weightlessly.
- The Dementors in the Harry Potter films. Also, in the Half-Blood Prince film, actress Georgina Leonidas (who played curse-victim Katie Bell) was filmed wet-for-dry for the scene in which she is suspended in the air, so that her hair would look like it was flaring around her head.
- The Ghost of Christmas Past in The Muppet Christmas Carol.
- The spirits that come out of the Ark in Raiders of the Lost Ark were filmed in a tank to get a ghostly flowing effect on their hair and clothes.
- For the scenes in Rainbow where the children ride inside a rainbow, all four actors were submerged in a pool with a green screen. You'll notice that even though the characters have dialogue here, it's never from whoever's in the shot or from whoever has their back to the camera in the wide shots. This was also one of the first scenes to be shot with prototype HD cameras.
- Doctor Who:
Examples of Dry-For-Wet:Film
- One of the oldest examples is 20,000 Leagues Under the Sea. There are scenes with actual divers, yes, but other scenes requiring James Mason and Paul Lukas to be seen through the helmets were accomplished this way.
- Exterior shots in The Abyss were done with models in a tank filled with air and smoke.
- Exterior shots of the underwater Aquatica facility in Deep Blue Sea were shot on a smoked-up soundstage, which bubbles added digitally.
- The "swimming in the bloodstream" scenes from Fantastic Voyage are all (very obviously) done with the actors hanging on wires and miming swimming.
- For Your Eyes Only: Many of the underwater scenes (including the close-ups between James Bond and Melina) were filmed on a dry sound stage and had lighting effects, slow-motion photography, wind, and bubbles added in post-production. Actress Carole Bouquet (Melina) had a preexisting health condition that prevented her from filming underwater.
- Nearly all the underwater scenes in the film version of The Hunt for Red October were actually done with models in a tank filled with air and smoke, because the smoke created the "just murky enough" effect the director wanted.
- The scene in Lara Croft: Tomb Raider The Cradle of Life in which Lara and her two companions travel down to the underwater Luna temple on motorised sleds was shot dry-for-wet on a smoked-up soundstage.
- Leviathan (1989) utilised dry-for-wet for the underwater scenes, with a combination of blue lighting, fan propelled debris and fog.
- Sam's near-drowning scene at the end of The Lord of the Rings: The Fellowship of the Ring.
- The drowned ghosts in The Lord of the Rings: The Two Towers, those which weren't CGI.
- The underwater scene in The Spirit was filmed dry.
- Doctor Who: "The Underwater Menace" used this for the sequences involving the fish-people, not entirely convincingly.
- Gerry Anderson shows beginning with Stingray (1964) used dry-for-wet underwater scenes, in which model submarines or marionette divers would be filmed through a narrow water tank containing bubble machines and fish.
- A rare theme park example: Tokyo Disney Sea's 20,000 Leagues Under the Sea ride achieves the illusion of traveling underwater by use of a suspended ride system through dry sets and vehicles featuring two-paned windows that contain water that bubbles as the sub pods "dive".