Smart lighting and the Internet of Things (IoT) may have been the most prevalent theme at LightFair International (LFI), but tunable-white LED technology was close behind and of course inherently requires some form of lighting controls to set color and intensity. Some of the most compelling examples of tunable solid-state lighting (SSL) came from Visa Lighting, Acuity Brands, and Philips Lighting. The tunable lighting, a form of human centric lighting (HCL), promises to deliver enhanced wellbeing for humans.

Interested in articles & announcements on tunable lighting & human-centric lighting applications?

Visa Symmetry

Visa Lighting was demonstrating its Symmetry product that was first announced a few months back. The dramatic 44-in.-diameter round luminaire is a recessed product with an interesting light engine design. The LEDs are mounted around the perimeter of the luminaire and directed up into a reflecting chamber with a dome lens serving to diffuse the lighting and deliver perfect uniformity.

Visa offers Symmetry in a number of models ranging from fixed-CCT options to a tunable model that has perhaps the broadest white range of any product displayed at LFI — 1650K to 8000K. The luminaire uses five channels of LEDs to deliver the broad range.

The Symmetry LED luminaire from Visa Lighting offers tunable lighting capability for use in human-centric lighting applications such as healthcare and education.

The extremely cool CCT can come into play in applications such as education when students need a morning jolt of energy or in healthcare as an examination light for doctors. Indeed, Visa is targeting both of those applications specifically with Symmetry. The model intended for healthcare can deliver 100 fc for examinations or can be dimmed to 30 fc for ambient conditions.

The Symmetry product is offered with DALI (digital addressable lighting interface) or 0–10V controls. Standard CRI is 82, although 90 CRI is available albeit with lumen output reduced by 15%. Visa is also offering the product in some saturated colors.

For now, the Symmetry product is only available in the relatively large size. But the company does plan to offer some smaller models going forward.

Acuity Mainstream Dynamic

Acuity Brands again featured its Mainstream Dynamic tunable technology at LFI this year. The company launched the product at LFI one year ago. Last year the demo was focused primarily on education. Now Acuity is promoting five different usage scenarios for products under the Mainstream Dynamic umbrella including Warm Dim, Tunable White, Architainment Color, Grayscale, and Color Accent.

The Grayscale concept was perhaps the most interesting. In a keynote presentation at Strategies in Light earlier this year, Jed Dorsheimer, vice president of commercial office lighting at Acuity, discussed the concept of simultaneous contrast relative to how the human brain and visual system works. Mixing darker gray luminaires in with mostly white luminaires makes people perceive the space to be more brightly lit. With products in the Acuity Rubik family and nLight-based nPODM controls, spaces can be lit to preset configurations or even to gentle yet dynamic modulated scenes.

Philips Lighting

Moving on to Philips Lighting, that company made a major tunable-white luminaire launch in August 2016. The systems were on display at LFI 2017.

Like Acuity, Philips is targeting education as a key market for tunable technology. At LFI, the company showed the four modes that are preset in its products for education. The Standard setting is for everyday activities. A Presentation mode features a warmer CCT for activities such as interactive learning. The Focus setting uses cooler CCT and high intensity to provide optimal conditions for exams. And the Calm mode features dimmed and warm-CCT light for relaxed activities. The teacher can easily choose the mode from a wall-mounted control panel.