Compositing is one of the most prevalent techniques in the visual arts – but what is compositing? Thanks to the technological advancements of the last few decades, composite images are seen everywhere. We’re going to look at different types of composite images from green screen to rotoscoping to CGI and everything in between. By the end, you’ll know how visual artists have used different types of compositing over the years to expert effect.
Composite Image Definition
First, let’s define compositingThe composite process encompasses a wide range of advanced filmmaking techniques such as green screen capture, computer generated imagery, and rotoscoping. This next video puts many of these techniques to the test – check it out here:
We’re going to break down different types of compositing, including the ones we referenced earlier, but first let’s quickly go through a compositing definition.
What is compositing?
Compositing is the process through which two or more images combine to make the appearance of a single picture. The composite process can be done on-set and in-camera or during Post-Production. There are dozens of different ways to composite shots but perhaps the most common example is when a weatherman is placed in front of a greenscreen with the weather details behind them.
- Multiple Exposure
- Blue or Green Screen
- Physical Compositing
- Front or Rear Projection
Compositing Graphics Like Méliès
Early history of compositing
Composite imagery existed in cinema long before the days of personal computers. In fact, the birth of compositing can be traced back to the turn of the 20th century with the works of Georges Méliès, one of the best movie directors of all time.
This next clip is taken from Méliès’ 1900 short The One Man Band in which he used a seven-fold multiple exposure technique to give the impression he was playing every instrument in a band.
Georges Méliès was a master of compositing techniques and quite literally pioneered the term “movie magic.” During the middle part of the 20th century, background projection (aka rear projection) was a massively popular compositing technique. But what is background projection? Well, it’s simply when the background content of a scene is projected onto a screen (or plates) to give the impression of one picture. This next clip from Alfred Hitchcock’s To Catch a Thief should clear up any confusion.
Nearly every driving scene from the Golden Age of Hollywood used background projection – it wasn’t perfect but it certainly did the trick.
One of the more complicated early compositing techniques was matting. Matting is the process of taking multiple elements of a film print and combining them – one at a time – onto a duplicate strip of film. Check out this next video to see some early special effects tricks in action.
Many of these camera tricks are easy to replicate on digital video. You don’t need CGI or high-fidelity LED screens – you simply need a camera, an editing program, and a penchant for creativity.
Digital Compositing Software Techniques
The art of layering visual effects
Nowadays, it seems that just about every studio film uses VFX – but what is VFX? Well, in simplest terms, VFX is a term used to describe visual effects compositing that take place outside of a live action shot. As such, the art of VFX is one way you can composite layers. And like I said earlier, we see composite VFX everywhere in cinema; even when it might not always be necessary. Don’t believe me? Check out this great behind the scenes video of the composite VFX in 2013’s The Great Gatsby.
It’s clear from watching the VFX in The Great Gatsby that we’ve come a long way from the early days of matting. But is that a good thing? The choice to use elaborate VFX comes down to an opportunity cost calculation on the behalf of the producers. Ultimately, I’d say that something is lost in the artificial flair that comes with the use of VFX simply for VFX’s sake.
But sometimes you need VFX to relay the magic of another world. Check out this video to see how we remade the cafe scene from Inception on a shoestring budget. You won’t want to miss how we break down step-by-step how to composite art assets into shots.
It’s amazing how much compositing we can do with such limited resources. Of course, it helps when you have a talented compositor and video editor like Keith doing the heavy lifting – but the point is that with enough time and practice, you can composite shots just like the professionals do.
Photo Compositing Techniques
Breaking down green screen strategies
A green screen is one of the most useful tools filmmakers can use to add visual effects compositing assets in Post-Production. If you’re wondering how to get started, check out our article on how to make a green screen with DIY green screen hacks. Perhaps it would be helpful to think about it this way: if you're combining several images into one, then a green screen or blue screen is the perfect tool for layering images to achieve that coveted final result.
Chroma keying is essentially the process by which a color is removed from an image. For example: it’s the process by which green is removed from a green screen video and replaced with something else in Post-Production. But as technology has advanced, some filmmakers have turned to a new strategy that removes the compositing process – check it out below:
It seems likely that green screens will one day become obsolete in studio films. However, it would be naive to think that smaller-scale productions would layer images in real-time with massive LED screens.
Compositing Animation Techniques
What is compositing in 3D animation?
Compositing animation was one of the earliest types of composite images in cinema. Max Fleischer was a pioneer of animated filmmaking and his idea to trace real footage changed the course of animation forever.
Check out this next video to see how Fleischer did it.
Rotoscope animation is the process through which live action footage is traced frame-by-frame. A Rotoscope effect can also be achieved in live action films by matting out objects – like it was here in the original Star Wars.
Remember: compositing is simply the process of taking two or more images and combining them to make a single picture. These “images” could be as small as the light-effect on a lightsaber or as big as a desert background on Tatooine.
3D Composition as an Art Form
What’s the purpose of compositing?
Now that we’ve looked at a variety of compositing techniques, perhaps we should ask: what’s the purpose of compositing? I’d say the purpose of compositing is to visually depict things outside the reality of an image. That statement is a bit of a catch-22 though; if an element can physically be part of a scene’s production design, it should.
Compositing is often best suited for building worlds that would otherwise be impossible to create in a practical fashion. In this next video, Charmaine from ILM explains how the team used compositing to build an otherworldly feel in Star Wars: The Last Jedi.
“We want to put people in a world that doesn’t exist and make it relatable for them.” - Charmaine, Senior Compositor at ILM.
A lot can be said about Star Wars: The Last Jedi but there’s no denying that the team at ILM did an excellent job of creating visual splendor. Ultimately, compositing proves to be the perfect strategy for achieving movie magic.
What is Double Exposure?
Double exposure is one of the most popular compositing techniques today – but did you know it was widely used in the Golden Age of Hollywood too? In this next article, we look at double exposure compositing examples from Vertigo, Blade Runner: 2049, and more. We’ll also show you how to achieve a double exposure effect in your own project.