CLD Lighting Fundamentals 3

Question 1

What is the primary purpose of a photometric report (IES file) for a luminaire?

Accepted Answer

To provide candela distribution data for lighting calculations

Answer

An IES photometric file contains the candela distribution data used by lighting software to calculate illuminance, luminance, and other metrics.

Question 2

Which of the following describes 'veiling reflections' in a lighting design?

Accepted Answer

Specular reflections from a task surface that reduce contrast and visibility

Answer

Veiling reflections are specular reflections from a task surface (e.g., glossy paper) that wash out contrast and reduce visual performance.

Question 3

What is the 'coefficient of utilization' (CU) used for in zonal cavity calculations?

Accepted Answer

To represent the fraction of lamp lumens that reach the work plane

Answer

The CU represents the proportion of total lamp lumens that actually reaches the work plane, accounting for luminaire efficiency and room geometry.

Question 4

What does 'glare' in a lighting system primarily result from?

Accepted Answer

Excessive luminance contrast in the visual field

Answer

Glare occurs when luminance contrast between a bright source or surface and its surroundings exceeds comfortable levels, causing discomfort or disability.

Question 5

What is 'mesopic vision,' and when does it occur?

Accepted Answer

Vision under intermediate light levels using both rods and cones

Answer

Mesopic vision occurs at intermediate luminance levels (approximately 0.001 to 3 cd/m²) where both rods and cones are active.

(CLD) Certified Lighting Designer Practice Test

(CLD) Certified Lighting Designer Practice Test

CLD Lighting Fundamentals 3