written by: Rianne Hill Soriano•edited by: Tricia Goss•updated: 10/26/2011
Imagination is the limit when it comes to the special effects any person can use in a movie production. From photorealistic to fantastic effects, these visual elements require combining technical and creative skills in order to produce the desired look for the film's visuals.
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Making Special Effects
Although there are many ways to create special effects in movies, they can be categorized into optical effects and mechanical effects. Optical effects involve the use of specific techniques to photographically produce or alter original images during the shoot or during the film's post-production. As a filmmaking term, special effects now covers specific shooting techniques, old-school post-production techniques involving optical printers used in 16mm and 35mm film formats, and visual effects done using digital technology.
Meanwhile, mechanical effects involves the use of physical effects, props and sets during the shoot such as mechanical props and characters, scale models or miniature elements, pyrotechnics, rear or front projections, live rain or snow effects, and make-up and prosthetic effects. Often times, by the film's post-production, these mechanical effects are further enhanced to make them look more believable or visually striking by adding some optical effects using special effects programs.
The green screen technique is widely used in film productions to combine live-action footage with special effects shots. Most of these works require shooting actors and possibly some crucial sets and props behind a green screen background. This green background is erased by the movie's post-production, and then the empty spaces around the shot are replaced by a different footage. This can be another live-action shot to serve as a new background for the scene, an animated background or a photorealistic recreation of a supposed live-action shot that is either impossible or impractical to shoot live. Some of the most popular examples of these are scenes that need an entire city blowing up in an action movie and a scene in outer space in a sci-fi movie.
Shooting on green screen generally requires an evenly lit green screen background, which can be bought, rented or made. Meanwhile, the special effects shots replacing the green screen background on live-action footage can be simply shot separately or created digitally. Some computer programs also provide users with a library of ready-to-use digital backgrounds for green screen shots.
Many special effects programs cater to different kinds of visual effects. There are also those that specifically accommodate a certain category of special effects such as particles, sprites or explosions. Generally, the more specialized programs offer more control and special features to make the effects tailor-made to the film's requirements. Some programs also provide users with ready-made special effects shots they can already use for their movies. Often times, they can also make certain alterations to these instant special effects shots for their projects.
Aside from stand-alone special effects programs, animation and video-editing programs may also be used for creating special effects shots. For more complicated effects, these programs can take advantage of plug-ins meant for generating specific special effects works. In doing so, the workflow considerably becomes faster as there is no more need to transfer in between programs to complete the project's special effects requirements.
Today, most special effects work in movies combines optical and mechanical effects to maximize the potential of their projects.
Once a movie is in the post-production stage, the filmmakers choose a specific production workflow fitting its technical and creative requirements. Completing all art requirements, importing them in computer programs and editing the film's final footage inclusive of the special effects don’t all follow the same basic workflow. Generally, the live-action footage is first edited offline, which means the special effects and image attributes of the original live-action shots are edited without any form of image alteration. The editor would assume that the special effects are finalized, when in fact they are still about to be made or are currently being produced. The offline edit serves as basis for the completion of the movie's special effects work. Once completed, the final special effects shots made, along with the color correction done on the entire film, are incorporated in the final edit, which is now called an online edit.
Aside from selecting the right production workflow for the film project, it is also important to decide which program/s to use to meet the demands of the film's special effects requirements. Any program of choice can vary depending on specific parameters such as making photorealistic, 2D-animated or 3D-animated effects, or shooting on green screen backgrounds.