Light Readings Against Humanity

The proper spacing for recessed downlights in a home depends on who you want to make happy: your light meter or your clients.

By David K. Warfel

We face a silent but growing crisis in lighting at home. The technology revolution of the last twenty years has brought us exciting new tools for delivering light, and concurrent scientific discoveries have dramatically deepened our understanding of light and its power over human biology. We can now have amazing lighting at home that looks better than ever and supports human wellness more than at any other point in the history of artificial light.

But, lighting at home is getting worse instead of better. We need new fixture designs, new control paradigms, and even new ways of delivering power, all of which I explored in previous articles. We may also need to rethink lighting calculations, which may be getting in the way of delivering better lighting at home.

Dining room. Lighting designers often utilize lighting calculations to get light levels just right, and that makes our services expensive. To help more people, we have to cut ourselves - and our light meters - out of the equation.

Before I dig into my desire to ditch my light meter, allow me to calm the fears of those of you who rely on lighting calculations for your daily work. I have no bone to pick with lighting calculations in general – they can be quite critical and helpful in the lighting design process. I personally enjoyed my days of running lighting calculations, as there is something soothing about getting closer and closer to the right ceiling uniformity ratio or target illumination, and it feels quite rewarding and reassuring when that moment finally arrives. Beyond mere enjoyment, lighting calculations help us save energy by dialing in the lighting and help us ensure the job turns out right for the occupants.

But, I continue to discover as I write this series on residential lighting that the rules change when we leave work and return home for the evening. Lighting calculations – and light meters – are getting in the way of helping others with light. Why? Because lighting numbers can be misleading, can miss the point altogether, and contribute to the prohibitive cost of good lighting at home.

Light Meter Choices. Precision calibrated meters and questionable smart phone apps matter less than a homeowner’s eyes.

I was recently asked, “Can you do photometric printouts for clients to see?” The question came from someone new to the lighting profession who had seen photometric reports provided by a manufacturer and was suitably wowed. A good photometric report, a selection of drawings with point-by-point calculations and false-color “heat maps,” makes for an impressive deliverable that practically screams, “Trust me, I’ve got this.”

The problem with providing these reports to clients is twofold. One is that virtually no homeowner really has any idea what the readouts mean, or how it will affect their home. Showing photometrics to the client is just a way of building trust, like a tax accountant showing us a stack of forms. We believe our accountant because we do not want to dig into the numbers, but they could be bilking us for thousands.

Even a handful of calculations will not tell us what our homeowner sees.

The second reason that photometric reports can be problematic is that they may be entirely misleading, creating a sense of professionalism and “rightness” while ensuring a lackluster lighting layout in the home. I took a look at the report my friend mentioned and found exactly what I expected: a home with rows and rows of recessed downlights pointing at the floor. The home was going to be flat, ugly, and cave-like…but the floor was going to be well-lit. The report convinced the client to buy the lighting, but it wasn’t going to be very good – just bright, like an overlit gas station canopy.

There is another reason that light meters are less useful at home than at work, and it has to do with occupancy. At work, lighting calculations help us find an average that we hope will work for a great number of people over the course of a few years. Illuminance targets help us guess what will be needed without having to complete exhaustive interviews of the six thousand employees that will occupy the building.

Light meters and calculations are good methods of finding an average, but at home there are only four light meters that matter: the left and right eyes of the primary occupants. There is no guesswork needed; simply ask the homeowner if it feels right. As Peter Ngai likes to say, "We all have a psychological appetite for brightness, and when we enter a space we will either be satisfied or unsatisfied."

An unsatisfied employee among hundreds or thousands is easy to gloss over. An unsatisfied homeowner is not. If the home “feels” dark to an occupant, it does not matter if we have four hundred lux or four thousand. Either way, we got it wrong.

These four light meters owned by a home’s occupants – their eyes – also take continuous readings, all day long, everywhere they go. Walk into a room and one reading will be taken upon entry. Take a step towards the counter and look at the cookies…how many more readings are being taken? Cook a meal, share it with friends, and it would take thousands of calculations and readings to accurately predict the experience, and it still would not tell us whether the homeowner is satisfied or not.

Our eyes take thousands of light readings every second, all day long.

But my biggest problem with lighting calculations is that they take time to craft, and our time to complete them must be billable. Would it be good to run lighting calculations of every room in a home? Absolutely. And our fees would show it. While this may not be a problem for the ultra-wealthy that are most likely to employ lighting designers, we have to give them up if we are to help more of our friends and neighbors.

The average home in North America has an architectural lighting budget of less than one thousand dollars. Total. It will cost that or more to run basic calculations, and the home will be dark because we spent all the money on a fee. If we are serious about helping more people get better light, we need to streamline the process.

We can move beyond lighting calculations in a number of ways. We could give every new designer a lighting package for their home; once installed, they would know how much light is needed and where without doing any calculations. We could run full calculations on a typical home and then amortize the cost out over twenty or thirty homes. We could over-design, adding in extra layers to make sure we have enough and then hope we can dim it down as needed.

Or we can train people to use the light meters they already have. We can help people see light.

I am increasingly convinced that we will only truly help a meaningful number of people get better light in their homes when we figure out how to deliver the results without any interaction whatsoever. People need to be able to do it themselves. And it must be more than just smart bulbs that change color temperature with a time clock; that is a lovely feature but a bit like saying all you need for good shoes is quality laces. Important, perhaps, but far from a complete picture.

The lighting industry makes better lighting possible, but also puts up barriers to getting great lighting at home.

How do we help people see light and imagine a better possibility at home? It will not be with lighting calculations that scare them into trusting us, but rather through reimagining how we talk about light, how we share what we do, and finding new ways of getting the message out beyond our beloved lighting software packages.

We have to develop an easy, foolproof way for homeowners to ensure they get better lighting at home. Then we have to share it in ways that cost the consumer absolutely nothing. Perhaps it is providing free design and fixtures to showcase homes – and providing a handout for every person that walks through on five ways to get great light at home. Perhaps it is shooting videos of our finished projects and sharing them on social media – and avoiding technical terms when we do. Perhaps it is pooling our resources and paying influencers to share better lighting with their followers – but in ways that truly serve the public and not just move product.

We can help people live better lives with light; this we know. Sadly, lighting at home is getting worse instead of better with an over-reliance on disc lights and glare-inducing decorative fixtures. Better lighting for our friends and neighbors may begin with setting aside the beloved tools we use at work. We must pay more attention to the only light meters that truly matter: the eyes of those living in the home. ■