Downlights emit a beam that is directed downwards at either a perfectly vertical or an adjustable angle. They are usually mounted on the ceiling and illuminate the floor or walls. They are offered with narrow-beam, wide-beam, symmetric or asymmetric light distribution. The cut-off angle of narrow-beam downlights means they are largely free of glare. On downlights with Darklight reflector, the lamp's cut-off angle is identical to that of the luminaire. This gives a luminaire with the widest beam possible while simultaneously having an optimised light output ratio. The use of a diffuser reduces the luminance in the luminaire and thereby improves the visual comfort and the evenness.

Criteria for downlights
- choice of lamp determines light colour, functional life, efficiency, light intensity
- emission angle determines the beam of light and is defined by the reflector and the lamp
- cut-off angle limits glare and increases visual comfort
- light output ratio is increased by optimised reflector technology