Illumination: Tree Lights at The Morton Arboretum in Lisle, Illinois, is a temporary, winter, light and video installation that measures 50 acres in size (out of the arboretum's 1,700 acres) and can be best referred to as an immersive experience. Encompassing roughly a mile of paved walking path around the arboretum in the middle of the Midwest, the exhibit features over 600 weather-proofed lighting fixtures and over 1,000 trees along the route.

The fixtures were manufactured by Elation Professional, an intercontinental lighting manufacturer homebased in Los Angeles, and rented out to the lighting designers by Intelligent Lighting Creations, a nationwide lighting design and delivery company.

The lighting design and layout was completed by Lightswitch, an audio, lighting and visual design firm that provides consulting services around the nation. John Featherstone, principal of Lightswitch, was the lead lighting designer for the lightshow ever since its inaugural year in 2012, and he has been assisted by Austin Shapley throughout all six years.

The original idea for the lightshow arose because the arboretum was looking for ways to increase visitor attendance during the cold winter months and Featherstone heard about this on the radio and contacted them with the idea of installing a light and audio show. Six years later, the immersive experience has been extremely well attended and has transitioned from a curious novelty to a wintertime tradition.

Setup took the firm roughly six weeks and included installing, programming and previewing the exhibit before it was opened to the public on November 3. This year, Illumination: Tree Lights at The Morton Arboretum was so well received that it even ran an extra week after the scheduled closing date, lasting until January 9, 2019.

Ideology
In addition to drawing visitors to the arboretum during the cold winter months, the landscape lighting design firm wanted to highlight the beautiful trees and plants of the arboretum in a different light.

"One thing we [tried] to underscore with Illumination [was] that the trees are certainly not dead in the winter but are dormant and sleeping," states Featherstone.
To do this, Lightswitch opted to use up-lights and projectors, instead of lights that wrapped around the trees, diverting visitor attention away from the light fixtures themselves and onto the trees instead.

"We did not want to use the trees as armatures for wrapping twinkling lights around them, but to up-light and illuminate them in such a way that made them stars of the show," Shapley relates. "This showed off the trees' natural and intrinsic features, such as the bark, thorns or vines."

Hardware
Almost all of the 600 fixtures used for the immersive experience are light emitting diodes (LED), making the total amperage of the entire project less than 300, on par with the same power draw as 3 homes per month.

Additionally, all of the fixtures chosen have been Ingress Protection (IP) rated and score IP65, IP67, or higher. The IP rating system is an International Electrotechnical Commission standard that attributes two numbers to fixtures in order to rank their resilience to particulates and water. Six is the highest the first number can go, meaning it is "impossible for dust to enter" the fixture; while eight is the highest the second number can reach, which would mean the fixture is suitable for continuous water submersion deeper than one meter.

Every cable used was also IP rated and connected to the fixtures with water-tight, screw lock connectors. Furthermore, every connection point is wrapped in waterproofing tape. Once an area's cables have been laid down, the cables are stapled down to the ground using 3-inch lawn wickets. This is coordinated with the groundskeepers to ensure none of the wires get damaged. When the ground freezes, the lawn wickets are so firmly held into place that sometimes they cannot be removed for several weeks after the exhibit closes!

Shapley relates that the light fixtures are usually able to stay warm enough to melt snow off the lenses without any need to clean them. He also mentions that, "Theoretically, it could all be powered by solar collection, which would be really cool."

In the beginning, the lighting design consultants needed to use generators in order to power everything. However, after six consecutive years, lighting infrastructure has been added to The Morton Arboretum grounds eliminating the need for any generators. Instead, the wires were able to be connected to about six transformers stationed throughout the arboretum.

The lights are controlled remotely by a grandMA2 lighting control console. It is stored in one of two small sheds that were temporarily erected specifically for the Illumination show. The lighting control panel is connected to a wired network, that then connectes into a wireless network in order to remotely control each light on the property.

Shapley concludes by mentioning that he and the team at Lightswitch, along with the other companies that worked on the show over the years, have learned how to really streamline the process of installation and deliver a truly captivating experience, allowing the Illumination: Tree Lights at The Morton Arboretum to be successful for six consecutive years and counting.