The Nuances of Shooting Green Screens or Chroma Keys

Scott from Whitney Media, Working with SunTrust on an internal video presentation.

Scott from Whitney Media, Working with SunTrust on an internal video presentation.

When it comes to video production in Orlando, recording a company spokesperson against a green screen can be an effective strategy.  It offers a certain level of sophistication and when done properly can look extremely professional.  The key phrase there is “when done properly.”  When done hastily and without thought it can make your video look like an amateur production.

Just to understand a little bit more…we see chroma key work every single day on the news.  Weather forecasters, sports anchors…they all stand in front of a green background that is replaced electronically with various graphics and motion backgrounds in post-production.

GEEK ALERT:  There’s some tech speak that’s going to be thrown around.  You’ve been fairly warned!

Here are four important factors in pulling off a successful key. 

1.      The camera you’re shooting the project with

Obviously all cameras are not the same.  Just because you’re shooting with a high definition camera doesn’t mean that your green screen project will be infallible.  There are a number of different of ‘flavors’ of HD cameras.  Let’s say your small business has decided they want to shoot in-house videos in an office with a green screen and the boss says here's $500 go pick-up a HD handycam at Best Buy.  Hmmm, chances are you’re going to be in for some challenges.  A camera’s color sampling capabilities will be a strong determining factor in how successful your “key” will turn out.  I know what you're thinking...color sampling??? Without going into a huge amount of detail, a camera’s color sampling relates to the amount of compression that might be going on in the image.  With cheaper cameras there will all sorts of compression.  The color and richness of the pixels are being compromised.  This becomes really evident when trying to do a green screen because you don’t have all the color information that’s required.  Cameras with a 4:2:2 color sampling will be able to create a successful chroma key if the background and subject are lit properly.  Beware of cameras with 4:1:1 and 4:2:0 color sampling.  Which brings us to our next point…

2.      Lighting

 Lighting is crucial in green screen work.  It’s not a matter of just pointing some lights at the subject and background and saying the job is done.  That’s not going to work!  The subject needs to be lit separately from the background, and you really don’t want any of the subject’s lights spilling off to the background.  The background should be lit evenly and flat.  No hot spots, no areas where the lighting falls off.  It’s also imperative that a backlight or hair light is used on the subject.  It should be subtle, not harsh.  This will also provide added depth and create separation from the subject and the background. 

3.      Space

  Our subject needs to be a proper distance away from the background.  We don’t want any shadows from the subject spilling onto the green background.  The on-camera spokesperson should be about 6-10 feet away from the green background.  That way you’re safe from shadows and you have a better chance of lighting the subject as a separate component from that distance.

4.       Clothing

 This point is just as vital as the others already mentioned.  If the background being used is green, the subject cannot wear any kind of green at all.  Stay away from any kind of green stripes or green lines in shirts, blouses, pants, dresses and vests.  That applies for any kind of accessories as well.  If the background is blue, the rules stay away from wearing any kind of blue wardrobe or accessories.  If a mistake is made, there’s little to correct it.  The subject will bleed through and be transparent in the areas where the colors match. 

Green screen work requires experience, skill and know-how.  They should only be used when there’s a purpose in mind for using that strategy.  The key to web videos these days is authenticity.  Employing artificial effects can come across as fake.

Have questions?  Chances are we probably have some answers for you.  Contact us!