“Wow! How is it done?”.
This is likely the very first reaction towards a jaw-dropping movie scene that we just experienced. No matter how old we get, this rhetorical question is often asked in disbelief.
Be it Superman flying, buildings collapsing around people as heroes save their world, or with animals that can break out into song, many adventures appearing on our theatre or television screen are moments that we simply cannot see being done in real life.
Well, for one, movies are the closest we can get to see the impossible become possible. To witness all our favorite fictional stories come to life. As for how most of that magic happens, you would have to acquaint yourself with one of the cinema’s greatest tools and aid — The Green Screen.
What’s a Green Screen?
Contrary to popular belief, the green screen is in fact, not just a screen that is green in color. Rather, it is much more fitting to describe it as a technique that requires a stretched out green material to be placed onto any surface to replace its displayed image or background.
To simply put it, the green screen is a method similar to the functions of a projector. With the help of external graphics and images, it is ultimately a tool that allows filmmakers or content creators to project whatever desired visual they might require in their resultant works.
How does Green Screen work?
The general technicality behind the Green Screen is the act of layering or as Infocus Film School best summarises it:
“Green screen is a visual effects (VFX) technique where two images or video streams are layered — i.e. composited — together.”
However, to go more in-depth to how this technique is actually executed would require us to go all the back to understanding its formal name, as well as the term coined for its primary special effects process: Chromakey.
Chroma which is the Greek word for ‘color’ which represents the purity of color while “keying” means to select a specific color. The act of chroma-keying is a technique best recognized in the field of visual effects by removing or replacing backgrounds.
What is often chosen and used for this background screen is a specific striking shade of green, due to it being the furthest difference from our skin tone and a color that contrasts with most of our everyday items.
To paint a clearer image, just imagine a person standing before a widescreen with nothing on it but one bright shade of green. What chromakey does is to separate anything with this specific color tone from everything else in the frame during the stages of post-production, then making it transparent.
In turn, external graphics or visuals can be inserted into the shot and onto where the green screen is. As such, now all we see behind the person is not a wide green screen but instead, the image or video that was placed atop later.
A technique that might take a while to understand, the green screen effect is actually something rather simple to execute. Even within the four walls of your own home.
Considerations behind the Green Screen
While it holds true that the green screen is a technique feasible with simply the presence of a plain wide green material and an editing software equipped with a “Chromakey” function, the factors to make every looming castle or crashing spaceship as realistic as they can be, do not just stop there.
Here are a few points to take note of when using the green screen during a shoot.
1. Practical restrictions
A no-brainer to start but a serious necessity to remember: Rid off all green at all costs. Or more specifically, the shade of green used for the green screen.
Put on a green shirt and be ready to have a transparent body between your head and legs on screen. Hold a green cup and you might as well not be holding anything. Have a mirror that caught the reflection of your green screen and count your luck with the empty holes found on its surface.
In the case that green might be a required color in your shoot or story, try your best to avoid shades that are anywhere similar to what you use for your screen. However, if worse comes to worst, there are always ways to achieve desired results during post-production.
With all that in mind, always do your practical planning properly during all works with the green screen, where one point should always take priority in your decisions: Avoid the bright green.
Just like how well-designed lighting can enhance moods for the looks in a photograph and the stories within a shot, a properly lit set can also ensure effective green screen executions. Flat and even lighting is seen as ideal since it reduces the amount of shadows, which helps with the chromakey process and image manipulation best.
An additional detail in similar regards is also to use the same type of lights on both sides of the green screen to ensure evenness throughout the entire frame. Positioning them at similar angles would also reduce risks of the beams overlapping each other in the center of the screen, disrupting the consistency in lighting.
Additionally, the green screen should also be lit separately from everything else. In the best-case scenario, your characters and objects should stand at least 6 feet away from your background, to avoid any green lights or reflection bouncing onto them. Similarly, this would also make sure that external shadows from your subjects would not be cast onto the green background.
3. Proportion and Movement
However realistic or believable an image or shot is depends largely on the relationship between the subject and the background. In turn, what stands as a link between these two parts is their proportion and the matching of movement in comparison to each other.
The background should move along according to the speed the subject is moving, and vice versa. If a man is walking slowly, the background edited behind him should go pass just as slow. Similarly, the subject should also be natural-looking in size when standing in front of the added infrastructure or props. A human child should not be the same height as a house.
Always think about your final work when blocking or positioning your characters and objects, or at least have a picture of your desired background when you are on the shoot. Only this way would you be able to convince your audience that what you have created is possible.
Uses of the Green Screen
Now that we have learned what the green screen is and how it works, it is time to understand how they help and are incorporated into a shoot. While the possibilities with this simple green material appear to be seemingly endless, here are the few of many uses and changes it brings.
To craft locations
Perhaps because they are places restricted to enter, or they are incessantly expensive to get, or simply for the plain fact that they don’t exist, some locations just cannot be translated from the script to real life. Well, at least before the green screen comes in.
Where external graphics and visuals can be superimposed onto any surface with the effect, green screens have the ability to make the impossible possible. They are the base for the construction and existence of most large-scale fictional worlds like Middle Earth in Lord of the Rings as well as safety nets for the dangerous out-of-reach places like the vast icy oceans of Titanic. Even so, they are the made-up unattainable location details like the rooftop city skyline in ABC’s Grey’s Anatomy.
Similarly, green screens are also the tools for crafting any films that might seem unfeasible story-wise, into live-action productions. Think the talking animals in Jungle Book, or fighting robots in Transformers; without stepping out into the outdoors, scenes or even an entire film for that matter can be made in one built studio setting itself.
To add in computer graphics
In the field of purchase, the green screen is very likely the most viable marketplace to getting anything infeasible, dangerous, or straight-out unavailable.
Just like how there are certain things in this world that we cannot get our hands-on, not everything we see in our favorite TV shows or movies can just be bought or attained. The control panel in Hunger Games was simply a green board where external graphics were added on while the stick of the lightsaber was painted green so that they could be digitally generated later.
Along the same line, not every effect or action can be simply executed in front of a camera. Green screens are added to every Marvel fight so that all explosions and collapsing of buildings can be layered in later with visual effects. Similarly, people wearing green body suits lift up and move around with objects to replicate them floating around in horror films.
To create characters
Locations and props are not the only things that are all available; roles that are dangerous or fictional are also difficult ones to get.
As such, a green bodysuit is often worn by people who will act out whoever or whatever their characters are meant to be. Later, computer graphics of these characters are then layered over these people, where their movements are tracked to match the on-screen actions and emotions.
As bodysuits, green screens perform its function best as described by Logan Baker from Premium Beats:
“Number one, it gives the animators and VFX artists a real, human reference point to work with. Number two, it gives the actors a real human to act with and react to.”
This has come to be a popularized technique for most characters in fantasy films like the twins, Tweedledee and Tweedledum in Alice in Wonderland. Additionally, they are also used for most movies where animals have to perform human-like or dangerous actions. The tiger in Life of Pi was a wrapped toy figurine, while the raptors in Jurassic World were crouching humans dressed in green bodysuits.
To add in information
Not just for the special effects in movies, the green screen is also a way to display information onto different moving mediums like the news or advertisements.
A green fabric or screen is often layered onto a specific spot where texts or graphics are meant to be done and added during post-production as opposed to being brought onto the shoot itself.
Such situations include the presenting of the weather forecast where details of the weather could only be known on the spot itself, as well as logos or graphics meant to be edited later, that might be displayed onto a screen in advertisements. Should you be an avid user of most social media, you would notice that even TikTok is using the green screen effect as one of their camera filters for entertainment.
The green screen is quite possibly one of the greatest and most effective tools with not just the cinematic landscape, but also every media outlet that produces videos or photos. It has proven to be able to lower production costs, bring realistic and iconic worlds and characters to life as well as become a visual tool to any story or detail.
While the act of turning the impossible possible sounds like an intimidating and expensive feat, the green screen effect can be easy and budget-friendly to achieve. As long as you take into consideration the factors listed in this article, your ideas and creations have the ability to be somewhat limitless.
Now that you have gotten a clearer grasp of this game-changer, I recommend this next: Search for green screen behind the scenes photos to all your favorite blockbusters. You are bound to find an impressionable one.
My name is James, I am a Content Creator, Professional Food Photographer, and Entrepreneur passionate about sharing tips and tricks within media topics.
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