CLD Cheat Sheet 2026

The 30 highest-yield CLD facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which professional attribute is most valued in lighting fundamentals within the CLD field? → Accountability and commitment to standards
2. Which approach best demonstrates mastery of controls and dimming in CLD practice? → Applying principles to novel situations with sound judgment
3. Maintained illuminance refers to: → The average illuminance level at which maintenance should be performed
4. Luminous intensity is measured in which unit? → Candela
5. What is the best practice for maintaining daylighting design performance over time? → Implement scheduled preventive maintenance
6. What is the primary function of a 0–10 V dimming signal? → Low‑voltage DC dimming control
7. When planning a project in Certified Lighting Designer, which element should be established FIRST? → Clear objectives, scope, and success criteria
8. Which approach best demonstrates mastery of energy codes in CLD practice? → Applying principles to novel situations with sound judgment
9. Which professional attribute is most valued in energy codes within the CLD field? → Accountability and commitment to standards
10. Mesopic vision occurs: → At intermediate luminance levels between photopic and scotopic ranges
11. Which lighting technique is commonly used to highlight architectural features? → Accent lighting
12. Typical North‑American branch circuit voltage for lighting is: → 120 V
13. What is the value of continuing education in interior lighting for CLD professionals? → It keeps professionals current with evolving standards and practices
14. What is the MOST effective way for new CLD professionals to build competency in their field? → Combining formal education, mentored practice, and ongoing professional development
15. What is the primary consideration when implementing changes to daylighting design? → Impact assessment and change management
16. How should a CLD professional manager address underperformance within their team? → Provide timely, specific feedback with support and a clear improvement plan
17. One footcandle is equal to: → Both 1 lumen per square foot and 10.76 lux
18. The Spacing Criterion (SC) for a luminaire indicates: → The maximum spacing-to-mounting-height ratio for acceptable illuminance uniformity
19. Circadian‑centric tunable white systems: → Shift CCT through day
20. What is the most important professional competency for CLD certification in sustainability? → Deep knowledge combined with practical application skills
21. What does a lighting control system allow users to do? → Adjust light levels and automate lighting schedules
22. In CLD practice, what is the best approach to quality improvement in interior lighting? → Use data-driven methods with measurable outcomes
23. In the zonal cavity method, the Room Cavity Ratio (RCR) is determined by: → Room dimensions including length, width, and cavity height
24. NFPA 101 requires minimum _____ along egress path. → 1 fc
25. DALI enables luminaires to: → Communicate digitally with addresses
26. In CLD practice, what is the best approach to quality improvement in lighting fundamentals? → Use data-driven methods with measurable outcomes
27. What is the SI unit for luminance? → Candela per square meter (cd/m²)
28. What factor is most critical when selecting task lighting? → Placement and brightness for the task
29. What is the most important professional competency for CLD certification in lighting fundamentals? → Deep knowledge combined with practical application skills
30. PoE lighting delivers: → Low‑voltage DC and data via Cat‑5/6