CLD Interior Lighting 3

Question 1

A lighting designer specifies a fixture with a beam angle of 15°. This fixture would most likely be used for:

Accepted Answer

Spotlighting a sculpture or architectural feature

Answer

A narrow 15° beam angle concentrates light into a tight cone, ideal for accent and spotlighting applications where precision is required.

Question 2

In interior lighting design, 'contrast ratio' between a task area and its immediate surround is recommended by IESNA to be no greater than:

Accepted Answer

3:1

Answer

IESNA guidelines recommend a maximum luminance contrast ratio of 3:1 between the task and its immediate surround to prevent visual fatigue.

Question 3

Which photometric distribution type describes a luminaire that emits the majority of its light downward between 0° and 60° from nadir?

Accepted Answer

Direct

Answer

A direct luminaire directs 90–100% of its luminous flux downward, providing efficient illumination of horizontal surfaces with minimal uplight.

Question 4

A CLD candidate is reviewing a photometric report. The 'zonal lumen summary' is most useful for:

Accepted Answer

Calculating the total lumens emitted in each vertical angular zone

Answer

The zonal lumen summary tabulates lumens emitted within defined vertical angular zones (e.g., 0–30°, 30–60°, 60–90°), aiding spacing and efficiency calculations.

Question 5

What is the primary purpose of a 'light shelf' in interior daylighting design?

Accepted Answer

To redirect daylight deeper into the space while shading the lower window zone

Answer

A light shelf is a horizontal reflecting surface positioned at window head height to bounce daylight onto the ceiling and deeper into the interior while shading occupants near the window.

(CLD) Certified Lighting Designer Practice Test

(CLD) Certified Lighting Designer Practice Test

CLD Interior Lighting 3