Greenscreens

Question 1

Briefly explain how keying a green screen works

Answer 1

VFX highlights the key color on the green screen (green, blue) and completely removes it, replacing it with a VFX element (stock footage, a plate; which is footage shot specifically for a project)

*The key color can’t appear on other objects in the screen

Question 2

Why are green screens typically green?

Answer 2

It’s the opposite of the pink hue in most skin tones (according to color wheel)

Not a lot of everyday things are green

Question 3

Name an advantage/disadvantage to using blue screens

Answer 3

Blue is not present in skin tones

Blue often appears on screen

Question 4

Generally, how far should the subject be from the green screen to eliminate contamination?

Answer 4

8-12 ft away

Question 5

How would you eliminate any ‘green spill’ on the subject?

Answer 5

Backlight

Question 6

Briefly describe proper green screen exposure

Answer 6

Should be exposed evenly across surface, within 1-2 stops from the key light

Question 7

Briefly define what is meant by the term ‘motivating light’

Answer 7

The practice of crafting artificial light to match/replicate a location/scenario

Question 8

What is the key to motivating light?

Answer 8

Finding the natural light direction (the opp. to where shadows fall)

Question 9

How does color tint (drift) of light occur?

Answer 9

The light color drifts off the L-R Orange - Blue color temp scale, resulting in a pink or green hue

Question 10

If a light appears at 100 CRI, what does this mean?

Answer 10

It lands perfectly on the L-R O-B color temp scale

Question 11

What does it mean if a light appears less than 100 CRI?

Answer 11

It’s drifting off the L-R scale up or down (pink or green), and doesn’t appear true to the camera sensor

Question 12

How can you determine the color tint (drift) of light?

Answer 12

Color Meters

Question 13

What holds up a green screen?

Answer 13

A foldable butterfly frame

Question 14

Fill in the blanks on the anatomy of the foldable butterfly frame

a) are the corners
b) hold the corners in
c) connect the frame to the stand

Answer 14

a) elbows are the corners
b) butterfly clips hold elbows in
c) butterfly clamps/elephant ears connect frame to stand

Question 15

Briefly describe the differences in stands designed for lighting as opposed to grip

Answer 15

Lighting: 750 spigot or 2k receiver

Gripping: 2.5” grip head or 4.5” grip head (lollipop)

Question 16

Name and briefly describe the 2 types of green screen

Answer 16

1. Chroma Green - less reflective BUT requires more light
2. Digi Green - more reflective BUT requires less light

Question 17

Define CRI

Answer 17

Color Rendering Index is a measure of how close a light truly appears on the color temperature scale