Effective Greenscreen Tips

By Ian Sandall & Peter Middleton (Video Mastery UK Faculty)

Greenscreen or Chromakey is a technique that’s widely used in corporate video, tv and movies. Presenters and actors are placed in front of a green or blue screen that can be replaced, live or in post-production, by a variety of different backgrounds in the form of video, photographs, graphics or detailed virtual landscapes. Green or blue is used as they are the colours furthest from our natural skin tones.

 

In movies and broadcast drama the technique is widely used to ‘place’ actors on fantastical sets or in scenes that just couldn’t be easily replicated in real life. A whole virtual set can be created using advanced computer graphics so that as the camera tracks the actors as they move and the perspective of the virtual ‘set’ changes accordingly, creating whole new worlds to explore in films such as Lord of the Rings or Dune movies.

 

 

Rather more mundanely, it is used in news broadcasting, weather reports and corporate video to place presenters in front of virtual sets, otherwise inaccessible locations, or an attractive background when filming in an otherwise humdrumlocation. Greenscreen is an effective way to add a little extra sparkle and creativity to your corporate productions.

 

 

The problem with greenscreen is that unless you are in a well-equipped video studio with ‘Ultimatte’ (or similar) – a system that allows you to see the effects on screen in real time – you are often working blind.

 

 

It is not just a matter of ensuring the chromakey background is completely smooth and evenly lit or that the subject is the correct distance away. When you’re working on location with a single camera, you have to determine the best lighting, camera angles and chromakey set-up to ensure that your subject fits naturally and seamlessly into your chosen background.

For example, is the light in the studio coming from the same direction as the light source in your background image, and is it the same colour temperature? And is the subject being filmed from the same perspective/angle as the background?

 

 

Without the necessary knowledge and skills, filming on greenscreen often doesn’t work out and your hard-pressed editor has a lot of work to do to try and make up for the filming shortcomings – if it is possible to do so!

In our one-day ”Filming Effectively with Greenscreen” course, we cover everything you need to know about shooting and post-producing greenscreen – in great detail.  The course is very practical, held at your premises, taught by a highly experienced UK producer, and we can work on one of your projects during the training.

Here are a few tips to get you started:

  • Have your presenter stand at least 2 meters from the greenscreen background – the further the better, really.
  • Ensure the green background is evenly lit. If possible, use a light meter to check this.
  • Light the subject separately from the background.
  • Use as low an ISO setting as possible and the best resolution (4K or above is recommended).
  • If you are filming the presenter full length, from toe to the top of their head, ensure that the greenscreen extends under their feet and consider filming in portrait.
  • Check the footage keys properly in your editing app before spending the whole day filming
  • Look carefully at the proposed background and ensure that the lighting on the subject is consistent with the lighting in the background image.
  • If the subject is referencing anything in the background image, ensure that they are pointing in the right place. Sometime a nod of the head in the general direction might be a safer bet,

All of this, and much more, is covered with hands-on exercises in the course. Here’s is what we cover:

When shooting, the placement of background and presenter is critical. There must always be enough separation between the two, otherwise you’ll have ‘green spill’ on the presenter that is very difficult to get rid of. We cover how to get round this easily. We show you how to light a greenscreen background and then how to light the presenter to match the intended background.

Filming with greenscreen outdoors presents its own unique challenges, all of which are addressed in the course. Finally, we cover all the camera settings that are required – especially the choice of lens, depth of field, ISO settings and shutter speeds – and we demonstrate the problems if this is incorrectly shot.

 

 

In post-production a slightly different workflow is often used. We show how to get the best ‘key’ from pictures and colour grading – and how to mend things when it all goes wrong. In the worst case you can use Adobe After Effects to create a ‘mask’, and new AI features, just included in this program, allow us to do that faster and more accurately than ever before. The latest version of Final Cut also includes a special ‘magnetic mask’ feature to help you with this too.

In conclusion, greenscreen is a wonderful technique that can allow you to be far more creative in any production. Having the flexibility of placing your presenter exactly where you need them, in front of a well-known city landmark, on a desert island or even inside a nuclear reactor, without leaving the office is a real timesaver and can add greatly to production values.

To book your place on our 1-day “Filming Effectively with Greenscreen” course call us today on 01604 583414 or visit our website at videomastery.co.uk.

Written by Ian Sandall and Peter Middleton of the Video Mastery UK Faculty.