Floodlight and projector are performance categories, not just product names

For architectural work, the real questions are how far the light must travel, how large the target is, how much spill is acceptable and what degree of optical control is needed. A narrow projector may be required for a distant dome or minaret detail, while a wider asymmetric flood optic may be better for a facade plane.

Selection criteria

• Throw distance and target dimensions
• Beam distribution and centre-beam candela
• Total lumens and system efficiency
• Glare shields, visors and cut-off accessories
• IP/IK rating and corrosion environment
• Mounting bracket, aiming range and service access
• CCT, colour quality and facade material
• DALI, DMX/RDM, 0–10V or other control strategy where required

Dome and minaret lighting

Separate the lighting tasks: dome shell, drum, finial, minaret shaft, balconies and crown may need different optics and aiming points. Lighting everything from one ground position often creates hot spots and excessive spill.

Facade lighting

Columns, arches, cornices and recessed surfaces can be modelled as individual layers. Combining controlled projectors with wall washers or concealed linear lighting usually creates better hierarchy than uniformly flooding the entire building.

Light pollution and neighbouring properties

External projectors should be aimed and shielded to keep useful light on the architecture. Calculation and on-site aiming are essential where the building is near roads, residences, protected heritage areas or dark-sky-sensitive environments.

Dynamic colour

RGB/RGBW can be appropriate for events and civic scenes, but permanent architectural appearance should still be evaluated in white-light modes. Controls should allow normal, event, late-night and maintenance scenes where the project calls for them.

Projector and floodlight selection matrix

Throw distance and candela

Long-throw lighting cannot be selected reliably from lumens alone. As the mounting distance increases, intensity in the required direction becomes critical. Review candela distribution, beam/field angle and the target size together. A high-lumen wide floodlight may be weaker on a distant minaret detail than a lower-lumen narrow projector.

Mounting strategy

• ground-mounted projectors with anti-glare hoods
• roof or parapet mounting where access is safe
• pole mounting for controlled aiming and clear sightlines
• integrated facade positions where luminaires can remain visually discreet
• reversible mounting solutions for heritage architecture where required

Exterior durability

Check more than the IP number. Exterior fixtures should be reviewed for drainage, thermal performance, cable glands, surge protection, wind exposure, corrosion environment, bracket strength and safe access for re-aiming or replacement. Coastal or chemically aggressive environments may require additional material protection.

Control scenes

Exterior architectural lighting can be divided into normal white-light, event, late-night and maintenance scenes. RGB/RGBW or tunable-white systems should still have a well-designed default white-light state. Scene programming can reduce power and unnecessary spill after peak hours.

Facade-lighting calculation checklist

• site plan and key public viewing directions
• facade elevations and material notes
• dome/minaret heights and distances
• realistic luminaire mounting points
• candidate photometric files
• aiming limits and shielding accessories
• neighbouring buildings, roads and sensitive receptors
• control zones and operating schedule

Frequently asked questions

Should the whole facade have the same brightness?

Usually no. A hierarchy of primary and secondary elements creates depth and reduces energy use.

Can one projector light an entire minaret?

Sometimes, but the result is often uneven. Shaft, balcony, crown and finial can require different positions or optics.

What is the difference between a floodlight and architectural projector?

Market terminology varies. For design, compare optical distribution, candela, aiming range, accessories and environmental performance rather than relying on the product label.