Visual Effects Compositing Techniques

Question 1

What compositing operation places a foreground element over a background using an alpha channel?

Accepted Answer

Over

Answer

Under

Answer

Multiply

Answer

Screen

Question 2

Which color space is preferred for high-dynamic-range compositing to preserve linear light values?

Accepted Answer

Linear light (scene-linear)

Answer

sRGB

Answer

Rec.709

Answer

CMYK

Question 3

What is 'keying' in visual effects compositing?

Accepted Answer

Isolating a subject by removing a specific color background

Answer

Adding keyframes to animation

Answer

Synchronizing audio to video

Answer

Locking layers to prevent editing

Question 4

What does the term 'premultiplied alpha' mean in compositing?

Accepted Answer

RGB channels already multiplied by the alpha value

Answer

Alpha channel applied before color correction

Answer

Alpha applied only to the luminance channel

Answer

Multiple alpha channels stacked together

Question 5

In compositing, what is a 'garbage matte'?

Accepted Answer

A rough matte used to remove unwanted areas before keying

Answer

A poorly made matte

Answer

A matte applied to trash bin footage

Answer

A matte created automatically by software

Question 6

What is 'despill' in green/blue screen compositing?

Accepted Answer

Removing reflected green or blue color from the subject

Answer

Removing spilled liquid from the set

Answer

Correcting overexposed highlights

Answer

Fixing motion blur on fast-moving subjects