Replacing backgrounds.
WHAT IT ENABLES
Placing a subject in any setting.
WHAT MAKES IT WORK
Even lighting on the screen Distance between subject and screen Lighting on the subject matching the intended background
WHY DISTANCE MATTERS MOST
Standing close causes green light to spill onto the subject, which is difficult to remove.
HOW MUCH DISTANCE
As much as the space allows, at minimum a couple of metres.
WHAT UNEVEN SCREEN LIGHTING CAUSES
Patchy removal, with edges that flicker.
WHAT TO AVOID ON THE SUBJECT
Green or reflective clothing Fine hair detail, which is difficult Transparent objects
WHAT TO CHECK BEFORE SHOOTING
The screen, for wrinkles and shadows.
WHY
Wrinkles create shadows that survive keying.
WHAT TO SHOOT AT
The highest quality your camera allows, with minimal compression.
WHY
Compression destroys edge detail, which is exactly what keying needs.
WHAT REALISM REQUIRES
Matching light direction and colour Matching depth of field Adding a shadow, where one would exist
WHY SHADOWS SPECIFICALLY
Their absence is what makes composites look fake.
WHAT TO CONSIDER INSTEAD
Filming against a real background, which is frequently easier and better.
