Spectrum

An Ideal LED Retrofit Solution For Fiber Optic Illuminators

Written by Tatiana Massano | February 21, 2019

The Aronoff Center is a performing arts center in downtown Cincinnati comprised of three multi-purpose auditoriums. The largest venue, Procter & Gamble Hall, features a beautiful fiber optic star ceiling that was recently upgraded with an LED retrofit. Theatre Consultants Collaborative (TCC) worked alongside Vincent Lighting Systems and The Black Tank to conceive and implement the theater’s new fiber optic lighting system using nearly 100 Rosco Pica Cube™ 4C fixtures. Below, Paul Sanow from TCC explains how and why they used the Pica Cubes as fiber optic illuminators to create a bright and colorful starlight effect.

The Objective

This 2015 post on the Aronoff Center's Instagram page illustrates the original fiber optic ceiling inside Procter & Gamble Hall using the uncolored MR16 illuminators.

The Aronoff Center opened in 1995 with an elaborate system of fiber optic illuminated fittings mounted in the ceiling panels. The installation was part of César Pelli's design. The installed system of MR16-based illuminators connected to stranded fiber optic bundles never lived up to the design intent. The illuminators were difficult to maintain, requiring frequent lamp changes; there are 79 illuminators, all wired to system dimmers. Each illuminator also had a remote-controlled dichroic color wheel that never worked reliably, forcing the operators to select a single color and never change the color. Tom Lane, the Aronoff's house electrician (now retired but involved in the design process), spent hours maintaining the original lights. He said, "It was a source of great frustration and we wanted to fix this as part of a larger lighting controls replacement project." Our goal was to find an LED-based, DMX-controlled fiber optic illuminator to replace the existing units in order to reduce labor and perhaps even improve energy efficiency. The unit needed to have excellent fade performance, decent color changing, and also be very quiet since all of the illuminators are in the audience chamber, behind an acoustically transparent ceiling.

The Challenge

Procter & Gamble Hall with its new, color-changing fiber optic lighting system - featuring Rosco Pica Cubes.

We had a great deal of difficulty finding a fiber optic illuminator that met our design parameters. All of the commercial units we found had some sort of shortcoming; some were too loud, some had poor color control, most were far brighter than needed, and nearly all had extremely poor low-end fade performance. It was shocking that even expensive lights with DMX-controlled RGB+ control could not manage fading to zero; they all snapped off. We had to have a fade all the way to zero because these are faded out in proximity to the audience at the start of each show. After testing several LED fixtures, we were becoming dismayed with the products available on the market. While considering our options, I stumbled across the Rosco Pica Cube and thought it might have the performance needed if it could be used in the application.

The Test

A Rosco Pica Cube 4C and a custom designed nose cone that attached the venue’s existing fiber optic bundles to the fixture.

In collaboration with Vincent Lighting System, The Black Tank and Rosco, we performed a test in the field. I built an adapter out of plumbing parts and Lexan to connect the Pica Cube to the existing fiber bundle. It was nearly exactly the same brightness as the original illuminators with the bonus of color changing. The Pica Cube has a fan but the noise inside the enclosure was undetectable. I also tested the heat buildup using the existing enclosures and found the temperature rise internally to be negligible in a 24-hour period.

From there, we 3D printed nose cones out of black colored ABS plastic. These nose cones were designed to easily attach to the front of the Pica Cubes using the four screws that normally hold the fixture's clear lens in place. We then painted the nose cones silver. After testing many different colored prototypes, the project team considered this to be the best solution, 1.) because silver paint is reflective and therefore maximized the brightness coming out the fiber optics, and 2.) the black plastic, being totally opaque, prevented light spilling from the nose cone.

The Solution

The fiber bundles are mounted onto an external bracket and the Pica Cube is carefully aligned so that the nose cone perfectly shoots light into the fiber bundle.

The TCC contract documents suggested mounting details either inside the existing enclosure or a new shroud. Vincent Lighting Systems used the existing enclosures and improved our mounting concept to simplify installation. They managed to use the existing Pica Cube bracket with some spacers and bolts to mount the light neatly inside. The Black Tank generated a handful of sample adapter funnels on their 3D printer, which allowed us to select the adapter with the best performance. Because the enclosures were already wired for 120V, we elected to install a duplex outlet inside the enclosure to plug in individual power supplies. We ran this by the local inspectors, and they accepted the assembly.

The Result

Rosco Pica Cubes were the only LED retrofit solution we could find that met our design objectives - reduced maintenance, color changing, reliable control, and good fade performance - and the price was extremely appealing, even with the custom-fabricated adapter from The Black Tank. Initial impressions are quite good. I'm very pleased with the installation and the performance of this retrofit solution.

To learn more about The Aronoff Center and its repertoire of upcoming performances, visit their website: www.cincinnatiarts.org/aronoff-center. For more information about the compact and powerful LED fixtures that Theatre Consultants Collaborative used as the fiber-optic illuminators to create the starlight effect inside Procter & Gamble Hall, visit the Pica Cube 4C product page on the Rosco website.