Practical Effects

Practical Effects are those which are done using props or special gear to produce an effect for the camera to film. Wind- and rain-machines, squibs, radio controlled vehicles, and pyrotechnics are all practical effects. So are breakaway furniture, walls or windows, and tilting or shaking platforms under the set.

They are probably the most common type of effect and often seen as giving the most realism. The truth of the matter is that they give rise to a lot of Hollywood Science but we are so used to seeing them that The Coconut Effect plays across nearly everything we see and we get used to them. Really all those car explosions, spurting veins and gun shots would behave very differently in reality, it's a shame reality is so unrealistic.

Rightly or wrongly, though, Practical Effects are seen by many as being in some way superior to Computer Generated Images or CGI. Certainly early CGI was much more prone to Special Effects Failure, the lower resolution, texturing and lighting flaws would push the images into the Uncanny Valley while even a bad practical effect could be seen to be physically real. The more modern CGI can be very conspicuous compared to well integrated practical effects.

A number of those who are Doing It for the Art will therefore stick to Practical Effects and the audience will often thank them for it. They will make proud announcements during promotions that everything in their movies is real and will take extra costs and risks to ensure their "realism".

Compare/Contrast Off-the-Shelf FX.

Film

 * Zathura. All the explosions and destruction felt very solid because they actually built the house interior on top of a tilt-able platform, filmed anything that required it to be intact, then proceeded to demolish the set as they filmed. Good luck doing a retake!
 * Many scenes that would normally be done with special effects in the movie Crank are in-camera, including the dramatic finale where.
 * Good Night and Good Luck, which was about the days of live TV, uses one effect for an elevator arriving at different floors. In most films this might be achieved by putting a Blue Screen behind the doors and overlaying a different background scene each time the doors open on a 'different floor'. In Good Night and Good Luck they used the old live TV trick of rotating the entire elevator set (with the camera fixed to the rotating floor) while the actors performed their scene in it, so that each time the doors opened you were looking at a different part of the exterior set.
 * A similar trick to Good Night and Good Luck was applied in John Woo's Hard Boiled. During the final act hospital shoot out, a long take is made of Tequila and Alan shooting their way through that lasts for 2 minutes and 43 seconds and doesn't break when they get into an elevator.
 * A similar trick was also used in the second pilot of Star Trek the Original Series. When Kirk, Spock, and Gary Mitchell ride the turbolift, a corridor wall is visible outside the doors when they close and the bridge is revealed when the doors open. They simply placed a wall outside the turbolift on the bridge set and wheeled it away while the doors were closed. The same trick was later done on the big screen in Star Trek II the Wrath of Khan. When Kirk and Saavik ride the turbolift, you'll notice that when it stops, a wall has been moved in to make it look like a different floor.
 * Remember the "Star Trek Shake", with actors leaning to the left and the right while the camera shook? Well, in Galaxy Quest, the whole set did the shaking.
 * Titanic actually had a stunt sequence involving over 100 stuntmen to roll down the set as the ship started sinking. And entire portions of the set had to be built to flood with water during those key moments.
 * Titanic might have used some C.G.I but most of its effects were still models, miniatures, and sets. It was mentioned on the "making of" that 90% of the effects were practical. The combination of computer graphics and practical effects might be why its visuals are awesome.
 * Batman Begins and The Dark Knight were very conservative on the post production special effects. Only the most extravagant or dangerous stunts were performed in post production. But certain scenes like Bruce saving Ducard from sliding off the edge of a cliff was done on location, with the actual actors wearing the necessary safety lines. The Dark Knight managed to film the wire-assisted flipping of an 18-wheeler by... actually flipping an 18-wheeler on the streets of Chicago. They got it in one try.
 * The 2007 Transformers film only had a handful of actors in front of green screens. While the robots were CGI of course, most of the stunts were entirely real, involving the actual actors shitting bricks while running from timed explosions. And even still there were a handful of images of the robots that were actually puppets: Frenzy in a few shots, Megatron's legs and even Bumblebee when strapped to a flat bed trailer.
 * While Walking with Dinosaurs (as well as its sequels, Walking With Beasts and Walking With Monsters) use a lot of CG, they almost always use mechanical puppets for close ups.
 * A habit probably taking its lead from Jurassic Park which did the same to great effect. While the effects, both practical and computer generated, have aged very well (the CGI probably even has better musculature), scenes like the kitchen chase with the Velociraptors would have been much less taut without the ability for close ups of the 'raptors' faces or having pots and pans being knocked and clashed and jangled by the dinosaurs.
 * Similarly with Deep Blue Sea they mixed in puppet and CGI sharks and in this case the puppets certainly moved and felt more realistic.
 * The earlier Harry Potter films also mixed animatronics and CGI. Fawkes, generally speaking, is an animatronic when he's perched and CGI when he's flying. The animatronic Fawkes could even cry "real" tears for the scene when he heals Harry's arm. Supposedly, it was so convincing that Richard Harris thought it was a real bird, commenting "they sure do train those things well." In the spider grove scene from the second film, Aragog is animatronic and his children are CGI. (CGI took over more as the series went along.)
 * Repo Man has an example that quite encapsulates the "practical effects are better" mentality. The otherworldy glow on the car at the end is glow-in-the-dark paint (bordering on Special Effects Failure if you let it), originally used because they didn't have the funds for CGI. Fast-forward to the present, however, and this ends up being far more convincing than the computer effects from the time it was made.
 * In the first Hellboy film, the writhing hair of the Sammael monsters was a practical effect—the hair was motorized! (Reportedly, when the producer saw the dailies, he was startled that they'd had time to put in CGI hair, when it wasn't CGI at all.)
 * The practical effects in Inception border on the ridiculous. Most notably, the famous spinning/zero-G fight scene was filmed using a full rotating set rather than any CGI or camera trickery.
 * In the 2001 version of Planet of the Apes only the space scenes and some backgrounds were done with CGI (as well as some harness wires removed in post), but otherwise it was all practical effects (including, among other things, the apes outrunning galloping horses).
 * In Ghostbusters many of the Library Ghost effects were practicals: books on wires, library cards being blown through copper pipes, etc. Also, when Stay-Puft kicks over a fire hydrant, the miniature actually sprays blue sand rather than have a gusher added in post-production.
 * The holograms in the climactic scene of Logan's Run were actual holograms - a brand-new technology at the time the film was made.

Live-Action TV

 * In the Star Trek: The Original Series episode "The Trouble With Tribbles", the tribble that moved along the bridge's safety rail had a small motor inside, making it possible to move on-set on its own.