Our friend and classmate David Zinn designed the costumes and scenery for “SpongeBob SquarePants: The Broadway Musical.” David’s designs have been nominated for Tony Awards, and his costumes were profiled in Friday’s New York Times. Congratulations David!
The Stage reported yesterday that “The European Union is considering banning tungsten halogen lamps in entertainment lighting, due to environmental concerns over their energy inefficiency.” There are so many reasons this is hopelessly misguided. Let me list a few.
First, the energy consumption of an entertainment venue is so low because the usage is so low, even for a Broadway or West End production with 500 lights. These theatres run eight shows a week, and average two hours per performance. That’s 16 hours per week, which is only one day of a retail or office space. So a theatre’s monthly hours of operation is equal to only four days of many other building types.
Second, the energy consumption is much lower than the connected load implies. 500 lights at 575W equals 287,500W. However, there’s never a time at which every light is on, much less on at full. A dark, dramatic scene may use only 5% of the total lighting equipment, and that won’t be a full brightness. One rule of thumb is that the usage of theatrical lighting is about 50%, so the 287,500W of connected load comes to only 2,300 kWH per week. That’s for huge shows. An off-off-Broadway theatre or community theatre with only 75 lights and five performances per week uses only 108 kWH per week.
Third, the impact on the entertainment industry, especially smaller and poorer companies, would be devastating. Yes, there are retrofit kits for ETC Source4 lights. However, all other brands of lekos, Fresnels, PARS, striplights, cyc lights, followspots, etc. don’t have retrofits. Tens of thousands of perfectly good equipment would have to be scrapped, but with replacement lights costing thousands of dollars (or pounds) many companies would not be able to replace the lost lights resulting in theatres literally going dark.
Fourth, these theatres would need new power and data distribution. Nearly all LED lights for the entertainment industry have on-board dimming and need to be connected to constant power, not dimmed power. But, nearly all lighting circuits in theatres are connected to dimmers. And, these LED lights need connections to the stage lighting control system, but this is an exponential growth in the number of data lines and the number of data parameters that need to be controlled. So, not only would theatres need new lighting equipment, but they’d need new control systems as well. Great for theatre consultants like Studio T+L, but ruinously expensive for theatre, opera, and music venues.
Fifth (I’m not done yet!) the quality of light and lighting will suffer. The most obvious impact is flicker of lights when they are dimming which, despite the assurances of most manufacturers, is a real, pervasive problem.
Why am I so heated about this topic? Because if it goes through in the UK some bright light of a state or federal legislature will think we should follow their lead. Again, it would be ruinously expensive for many, many performing arts companies. The entire lighting industry is converting to LEDs. In architectural lighting there are very few reasons to decide against using LEDs, so most new installations are mostly LED. The same is true in the entertainment industry. However, there is an enormous base of existing equipment for which there are no retrofit options. Rendering that equipment useless by removing replacement lamps from the market is outrageously heavy handed (and ham handed). Let the industry organically continue its transition to LEDs, don’t force it. The damage far outweighs the benefits.
Earlier this year we started working with New York’s Target Margin Theater on converting a two story warehouse into a new studio theatre, rehearsal spaces, and office space. Two acoustically isolated rehearsal rooms were built at the beginning of the summer. When bids for the resilient stage floor were twice as high as expected the team decided that TMT could build it themselves.
TMT hired a technical director to oversee a crew of volunteers installing the resilient floor we designed and building portable seating risers. The project required:
- 50+ volunteers over 5 days
- 125+ sheets of plywood
- 50+ sheets of masonite
- 2,000 rubber pads
- 75+ 2x4s
- 15 gallons of black paint
- 3 gallons of wood glue
Target Margin now has a great floor and a set of risers. Here’s a gallery of photos showing the progress.
Next steps will include a disconnect for stage dimmers, a pipe grid, and a new mechanical system.
Yesterday we surveyed a site in D.C. for a possible new Vapiano restaurant. The NYC flagship renovation begins soon, and a new location opens in Chicago later this year, all with lighting design by Studio T+L.
Measuring and describing the brightness of colored LEDs is an increasingly important part of a lighting designer’s practice. They are used more often, and in more types of projects, than ever before. Yet, we don’t have an accurate method for understanding exactly how much light is being produced and how bright it will appear. It’s a problem that the lighting industry needs to solve, and soon.
The human eye does not respond to all wavelengths of light equally. We have the greatest response to the yellow-green light of 555 nm. Our response falls off considerably in both directions. That is, wavelengths of light do not contribute equally to our perception of brightness. The sensitivity curve of the human eye is called V(λ) (pronounced vee lambda) and is shown below.
The definition of a lumen, the measurement of brightness of a light source, is weighted using V(λ) and essentially assumes that the light source emits light across the visible spectrum – in other words, it produces a version of white light.
Light meters are calibrated to measure white light using V(λ) so that their measurement of brightness corresponds with our perception. Individual colored LEDs emit only a fraction of the visible spectrum, as shown below in the graph of V(λ) and the SPD of a red LED, and that’s the problem.
Light meters measure the light that the colored LEDs provide, of course, and this information is included on an LED fixture manufacturer’s cut sheets, but it often makes no sense. For example, an RGBW fixture I’ve arbitrarily selected reports the following output in lumens: Red 388, Green 1,039, Blue 85, White 1,498. Since brightness is additive, the output when all LEDs are at full should be 3,010 lumens. However the Full RGBW output is given as 2,805 lumens! That’s 7% lower than what we expect.
The essential problem is that the colored LEDs give the light meter only a fraction of the spectrum it’s designed to measure. The meter provides a result based on its programming and calibration, but the results are often nonsensical or at odds with our perception. This problem doesn’t affect only architectural lighting designers. Film and TV directors of photography and lighting directors also rely on a light meter’s accurate measurement of brightness in their work, and when using colored LED fixtures the light meter is likely to be wrong. In fact, even white light LEDs can be difficult to measure accurately because of the blue spike in their SPD.
For now, the only way to accurately assess the brightness of colored LEDs is to see them in use. Lighting professionals need to let manufacturers and others know that the current situation is not acceptable, and that an accurate method of measuring and reporting the brightness of colored LEDs is a high priority. Talk to fixture and lamp sales reps, fixture and lamp manufacturers, and decision makers at IES, CIE, NIST and other research and standards setting organizations. There’s a solution out there. We need to urge those with the skills and resources to find it to get going!
In a project meeting yesterday a team member said that LED stage lights would save the owner money. While there are many reasons to include LED lights in a theatre’s equipment inventory, cost savings is not one of them. We’ve written a white paper, LEDs In Stage Lighting, that includes an economic analysis and simple rate of return. Get a copy here.
I often tell my students that design is as much a process as it is a product. Even so, they (and some of my clients) sometimes want to go from first meeting to finished design in one step. I suppose one could do that, but the result wouldn’t be a thoughtfully appropriate design, it would just be fixture selection. The difference lies in the early part of the design process where we gather information about the project and the expectations of the stakeholders, followed by an analysis of that information towards the stated goals of the project. Only after completing those two critical steps can we begin the work of putting the design together and executing it. Here’s one way of looking at the entire process.