Outdoor & Landscape Lighting Flashcards

What does the term 'Dark Sky compliant' mean when applied to outdoor landscape lighting fixtures?

Answer: The fixture is designed to minimize uplight, glare, and light trespass to protect the night sky

Dark Sky compliant fixtures, recognized by the IDA (International Dark-Sky Association), limit uplight and glare to reduce sky glow and protect natural darkness.

When using a landscape lighting photocell to control fixtures, what is the typical turn-on illuminance threshold used?

Answer: 2–3 footcandles (22–32 lux)

Photocells for outdoor landscape lighting typically activate at approximately 2–3 footcandles (around dusk) and deactivate at a similar level at dawn.

Which landscape lighting design principle recommends limiting the number of fixture types and finishes on a single project?

Answer: Fixture coherence (unity)

Fixture coherence or unity recommends minimizing the variety of fixture styles and finishes to create a visually harmonious outdoor lighting scheme.

What is the recommended burial depth for 12V low-voltage landscape lighting cable (not in conduit) under normal pedestrian areas per common installation guidelines?

Answer: 6 inches (15 cm)

Low-voltage (12V) landscape cable is commonly buried at a minimum of 6 inches in pedestrian areas, though deeper burial is recommended for protection against digging.

A landscape designer is lighting a flagstone pathway and wants to avoid 'hot spots' (overly bright pools of light with dark gaps between them). Which adjustment should be made?

Answer: Increase the beam angle of the fixtures

Increasing the beam angle (using wider flood lenses) spreads light over a larger area, overlapping adjacent fixtures' coverage to eliminate dark gaps between pools of light.

Which standard published by ANSI/IESNA provides recommended illuminance levels for outdoor parking areas and pedestrian walkways?

Answer: ANSI/IES RP-8

ANSI/IES RP-8 (Roadway Lighting) provides illuminance and luminance recommendations for roadways, parking areas, and pedestrian walkways.

What effect does pointing an uplight at a narrow beam angle (10–15°) versus a wide beam angle (40–60°) have when uplighting a tall tree?

Answer: A narrow beam concentrates light on a specific trunk or branch, while a wide beam floods the full canopy

Narrow beam angles concentrate light on a specific element like the trunk or a key branch, while wide angles distribute light broadly across the full canopy.