Lighting Design & Illumination Flashcards

What does the Color Rendering Index (CRI) measure?

Answer: How accurately a light source renders colors compared to natural light

CRI measures how accurately a light source renders colors compared to a reference natural light source, on a scale of 0–100.

Which type of lighting provides general, overall illumination for an entire room?

Answer: Ambient lighting

Ambient lighting provides general, overall illumination for a space and serves as the base layer of any lighting design.

What unit is used to measure illuminance — the amount of light falling on a surface?

Answer: Foot-candle

Foot-candles (or lux in SI units) measure illuminance — the quantity of light striking a surface per square foot.

Which color temperature range (in Kelvin) is typically described as 'warm white' and preferred in residential settings?

Answer: 2,700K–3,000K

Warm white light falls in the 2,700K–3,000K range, producing a yellowish, cozy tone commonly used in homes and hospitality spaces.

What is the primary purpose of task lighting in interior design?

Answer: To provide focused illumination for specific activities

Task lighting provides concentrated, focused light for activities such as reading, cooking, or working at a desk.

What is a lumen?

Answer: The total quantity of light emitted by a source per unit time

A lumen is the unit measuring total luminous flux — the total light output emitted by a light source.

In interior design, 'layered lighting' refers to which approach?

Answer: Combining ambient, task, and accent lighting to create a flexible, well-lit environment

Layered lighting combines ambient, task, and accent light sources to create depth, flexibility, and visual interest in a space.