CLD Lighting Design Principles & Techniques 3

Question 1

What distinguishes 'ambient' lighting from 'task' lighting in a layered lighting design?

Accepted Answer

Ambient provides general background illumination while task lighting delivers focused light for specific activities

Answer

Ambient lighting establishes overall baseline illumination for a space, while task lighting supplements it with higher, directed light for work activities like reading or cooking.

Question 2

What is the recommended maintained illuminance level for a general office work environment per the IES Lighting Handbook?

Accepted Answer

300–500 lux (30–50 fc)

Answer

The IES recommends 300–500 lux (approximately 30–50 footcandles) as the maintained illuminance target for general office tasks.

Question 3

A designer uses a 'scallop' effect on a wall. How is this typically achieved?

Accepted Answer

By spacing recessed downlights too far from the wall, creating overlapping semi-circular patterns

Answer

Scalloping occurs when recessed downlights are positioned far enough from a wall that their circular beam patterns land as overlapping scallop shapes rather than an even wash.

Question 4

What is the role of the 'adaptation luminance' concept when designing for transitions between interior and exterior spaces?

Accepted Answer

It accounts for the eye's adjustment time to different brightness levels, preventing discomfort or hazard

Answer

Adaptation luminance guides how transition zones should be lit to allow the eye to adjust gradually between very bright and very dim environments, reducing safety hazards.

Question 5

Which metric is used to evaluate a light source's ability to render human skin tones accurately?

Accepted Answer

CRI R9 value

Answer

The R9 value within the CRI system specifically measures how accurately a light source renders saturated red, making it critical for evaluating skin tone reproduction.

(CLD) Certified Lighting Designer Practice Test

(CLD) Certified Lighting Designer Practice Test

CLD Lighting Design Principles & Techniques 3