What is Green Screen?

What is Green Screen?

Everyone’s seen a video like this; A famous person is acting in a studio somewhere in Hollywood, surrounded by walls, people and other objects coloured with a bright, lime green hue. Then, in the final film, the same person is seen battling dragons or running around in an unbelievable science fiction world.

Whether it’s for creating unimaginable new worlds, for transporting people back in time to a bygone era, or for creating the entire set of a television news studio, green screen has become synonymous with creating special effects in video. It has seemingly enabled every and any idea to come to life – albeit with varying levels of success.

Given the general public’s awareness of the technique, it’s easy to see why people may think that a green screen is a silver bullet for solving any and every challenge that faces a video. After all, if a green screen lets Warner Bros. bring the world of Harry Potter to life, surely it can make a humble corporate video better?

What most people don’t realise is that the green screen, in and of itself, doesn’t actually do anything.

How it works

At Southpoint Films, we have a green screen in our Southampton-based video production studio. In all honesty it’s just a wall that we’ve painted green. Unlike some of our cameras, it’s not some high tech piece of kit that we’ve made a huge investment in. You can have your own for the cost of a few tins of paint – and the cost of a wall, of course!

The thing that makes the green screen work is the technology behind it. Firstly there’s a process called chroma keying, then there are a variety of visual effects processes that are used to build a digital scene around the person or object you’ve filmed.

In simple scenarios the chroma keying process works by analysing a photo or video and removing all of the colours that match a defined criteria. For example, removing all of the green in an image. 

While this process can technically work with any colour, luminous green is the most commonly used because it’s an unlikely colour to appear on a person or object. Blue screens are also quite common too, but the colour blue often appears in business attire, so we don’t tend to use it for corporate video production.

Once the chroma keying process has been completed, the editor will have footage with lots of transparent sections where the green once was. This footage can be overlaid on top of an existing image or video clip, or it can be used in advanced animation applications to create digital scenes that blend real footage with animation.

This may sound simple but the reality is that post-production of this kind is very time-consuming and intensive to achieve. There’s a reason why major blockbusters like Star Wars finish filming several years ahead of their release; an army of visual effects artists spend all of that time turning the green screen footage into the stunning effects-laden movie you see in the cinema. It’s no small task!

Using Green Screen for corporate videos

Given that we have our own green screen studio, as well as an array of portable green screen options, we often find ourselves evaluating the best ways to use this technique to enhance our corporate video productions.

In our experience, green screen is best reserved for simpler applications, like adding a background to an interview or piece-to-camera. If planned well the effect can be undetectable, which is the primary goal when using this technique to create realistic videos. If there are technical reasons such as a location being too loud, or a health and safety challenge, using a green screen may be your only option.

For anything more ambitious, green screen is probably not the best option. A video that features people moving around or interacting with a location is best done on location. The amount of time and resources needed to make a convincing video in a green screen studio will vastly outweigh the benefits of hiring a suitable location, even if it’s not quite the location that was originally hoped for. The last thing anybody wants is for the audience distracted from the message of the video because the visual effects are awkwardly produced.

On the other hand, there’s a chance that you might actually be looking for something a bit different, in which case using a green screen could be the perfect tool. There are plenty of unusual ways that green screen footage can be used to help your business or brand stand out. 

Here’s a music that I worked on for my friends Minus Alive that was filmed entirely against a green screen for a heavily stylised result, which helped the band differentiate themselves from their peers.

While the needs of a band and a business are very different (and I only make the occasional music video for fun – not commercially), there’s a lot to be said about the common need to stand out in a crowded marketplace.

If you’re interested in using green screen for your next video, please get in touch with us. Even if you’re not sure whether it’s the right fit for your project, we can offer advice on the best way to achieve the result you’re looking for, and make suggestions for alternative approaches too. We look forward to hearing from you!

This article was originally published on 8th April 2015.
It was last updated on 13th February 2020.