How to set up chroma key correctly

Whether you are a VFX producer, manager, or intern, you’ve probably heard about chroma key technology. It’s something that is used not only in just about every movie these days but in music videos and social media content too.?

If you already have experience with chroma key or it is something completely new to you, the following guide for filmmakers should help explain the concept to you. This is an extract from the article 'Chroma Key Technology: Guide for Filmmakers' on our website.

Step 1: Consider the purpose of your chroma key shot?

The first step to chroma keying correctly is to consider why you are doing it in the first place. What sort of scene are you trying to achieve? Are you trying to place the main character of your film into a CGI spaceship, or are you simply trying to mix two different backgrounds together? Take a while to consider this, as it will determine how you will need to layout your shot.?

Step 2: Prepare your chroma key background?

Once you have figured out what purpose chroma keying will hold in your VFX production, it’s time to prepare the content for the scene. This could take a while depending on the complexity of the content, so it’s important to plan the previous step ahead within suitable time!?

Step 3: Consider what colours your scene will include?

You will now need to refer back to the section of this guide on chroma key colors. Consider what colors will be used within your scene – ask yourself the following questions.??What color will the main subject’s outfit be? Do you have a variety of color screens to work with or only a green screen? This will be very important in determining the success of your chroma keying, so choose wisely!

Step 4: Set up the screen

You should now be ready to set up your chroma key screen and start filming. You should take extra care in ensuring that everything is perfect at this stage. Make sure the room is well lit, and that there is no inconsistent lighting or coloring on the screen. Make sure that it is completely flat, and that there is no wind or drafts that is going to compromise its steadiness.?

Step 5: Film your shot?

It’s now time to start the filming process. You will need to ensure that your actors or subjects are suitably framed within the colored screen. Make sure they don’t do anything silly like bump into it or show any awareness of it, as this would break the VFX illusion!

Step 6: Editing the chroma key shot?

You should now have your chroma key footage ready to be edited. Simply import your shot into a chroma key software, and get to work. If you completed Step 4 correctly, this shouldn’t be too much work. However, if there was any inconsistency, you may have to do some manual chroma keying in post-production.

Bonus from FRENDER: best chroma key software

Back when chroma keying was first invented in 1940, filmmakers were actually achieving the technique through film reels alone! It was a painstakingly frustrating and time-consuming process, but thankfully we have software these days to handle the heavy work.?

When it comes to industry-standard chroma key software, you will generally be looking at accessing Adobe After Effects. This software is excellent for all kinds of VFX production and post-production and features a specialized chroma key editor for seamless chroma keying. Furthermore, it integrates within other Adobe filmmaking software such as Premier Pro, facilitating seamless chroma key workflows.

Another solid choice is PowerDirector, particularly for Windows users. Whilst this software is perfectly capable of achieving chroma key techniques in the same way as After Effects, it must be said that it can feel a little clunky and frustrating to use at times.

Many producers will also swear by Final Cut Pro X for chroma keying. Once again, this is decent software and can definitely achieve the technique, but it is also a bit more rudimentary than After Effects and PowerDirector. It’s also only available for Mac users, so Windows users will have to look elsewhere.?

Whichever software you choose, chroma-keying is thankfully a lot easier than it was back in 1940. There are even in-built chroma key tools on mobile video editing software these days. Whichever method you choose, we wish you good luck, and don’t forget to choose your chroma key color carefully!