GREEN SCREEN, SECRET BEHIND BLOCKBUSTER TRICKS, KNOW THIS

 The world is fast changing, technology replacing traditional methods. Filmmaking as earlier define in our previous Articles A GUIDE TO FULL TIME FILMMAKING we understand Filmmaking is the art of telling stories via audio/Visual devices for diverse reasons and purpose by capturing  motion pictures in frames

Traditional filmmaking of Light, Camera, Action is gradually being replaced with Green screen technology and virtual Production. Each system requires proper understanding in usage to creatively tell a story via motion pictures. In this article, we will be looking at the Green screen technology

CHROMA KEY

As wonderful as it is, the era of green screen and to it's gradual replacement with virtual Production many filmmakers are yet to be conversant with this technique which is more problem solving, escape route from certain Challenges

WHAT IS GREEN SCREEN

Green screen or Chroma are long backdrops placed behind shots for later digital replacement in post Production to archive Specific creative imagination. importance of green screen

• Reduce cost and Stress of mobility
• Reduce cost in location hiring e.g airports, supermarkets 
• Reduce cost in hiring certain Props which can be CG generated e.g cars, airplane etc
• Creation of possible reality features(super humans, landscape, mountains,Animals etc..) that naturally are impossible 

However they are possible disadvantages of using green, this disadvantages are as a result of no or little understanding of this technique which are commonly color spill, high reflective, poor compositing and Animation that frustrate energy.

 In a nutshell proper knowledge and Understanding is key to escape color spill, reflective and mastering digital compositing and Animation.

Requirements for setting up green screen

• Sufficient Chroma material
• Stands and clips
• 3 to 4 Lights positioning
• Camera/Tripod/lense(s)
• Other applicable

Settings green screen for shoot most be treated and set up with alot of caution and precautions, a common DIY set up should be at least 12ft square. The following among others are helpful tips for set up

1. Properly stalling of green chroma with stands, well clipped treating wrinkles for proper smooth background flow down

2. Accurate positioning of Light to expose the Chroma separately from the object or Character. Evenly lighten will save colors spills and reflective issues

Note!! In making choice of chroma  materials reflective materials should be avoided, light absorbing materials are solution to reflections.

 Also Object or Characters most never be costume with Green color clothing, reflective objects like glasses and mirror should be avoid and if a most to be used, should be treated with caution

Light objects or Characters separately from the Chroma to avoid light spills on characters or shadows falling on background , Objects or Characters should be aleast 3ft to 6ft away from the backdrop this also solve shading issues,lastly but not the least let the lightening exposure of your footage be in corresponding with your CGI elements

Filming on green backdrop will require attention to camera setup since it differs from outdoor shoot. Most filmmakers often get it wrong at this point which can in turn frustrate creative effort.

Understanding the exposure circle for capturing frames on backdrop should be top most top priority after evenly lightening  green backdrop.The relationship between the ISO, APATEUR, SHUTTER SPEED for green backdrop slidely contradict outdoor shoot in this

A native or lower ISO or slidely above the native ISO is Recommendable this avoid much image light since physical Lighten has well expose both the backdrop and Character evenly ,this also totally avoid image noise created by higher ISO. The key here is having camera ISO at native or possible best lower ISO 

An APATEUR range of 4,5,6 highly recommended because it controls and avoid much Light from entering the camera, keeping everything(Backdrop, Character) in Focus for proper keying reading in post software. The idea here is keeping a deep Depth of Field to have everything in Focus than a shallow Depth of Field

Filming on green backdrop will demand avoidance of motion blur, to best Achieve this using cam on tripod, a SHUTTER of 1/120 or 1/125 at 30fps or 60fps quite Recommendable. The key here is avoid motion blur by keeping possible best Faster shutter speed that avoid motion blur. situations may arise for rules to be broken but creative people act with safety mentality. MORE HERE

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