Understanding lighting your meeting room
Intensity, angle, and color all come together to make a more engaging meeting experience.
Introduction
Anyone who has ever taken a picture of someone with their back to a window knows the importance of lighting to a camera lens. The problem is, how do you best overcome this? Just close the blinds? Turn on your overhead lights? Crank up the flash? Have someone hold a flashlight to the subject face? As ridiculous as it sounds the flashlight idea might be the closest one.
Lighting is a dynamic and often frustrating medium. There are so many confusing technical terms “lumens,” “color temperature,” “candle power,” that your average point and clicker or home office Zoomer couldn’t care less about deciphering it all. However, a few key lessons and easily installed devices could dramatically improve your web stream or Teams call.
In order to optimize your web experience there are three main components you should look at. Color temperature, brightness (lumens/candela), and angle.
Color Temperature
Color temperature is by far the most noticeable to the eye but perhaps the least understood. The most ubiquitous place this comes up is in the hardware store when you’re trying to decide between the “warm” and the “cool” 60-watt light bulb. These are broad subjective terms that apply to specific measurements. “Warm” and “cool” are referring to the kelvin temperature scale. This is a measurement of heat in traditional light sources. In a traditional incandescent light there is a black filament that is heated to extreme temperatures to create light. This heat is measurable, the hotter it becomes the more spectrum of light it creates. This is why the “cool” light bulb at your neighborhood hardware store has a higher Kelvin (heat) rating.
A true high Kelvin light is extremely difficult to recreate on a small scale. Reproducing the kind of heat and light spectrum the sun creates take a tremendous amount of energy. Therefore your regular home “cool” light bulb or cheap LED headlights appears to be a blue light. They are attempting to mimic a broad spectrum, high heat light source.
For our purposes it is important to understand how these measurements affect what a web camera lens picks up. Lower color temperature lighting is soothing and warm in real life but can come across as dim and ominous in video. This is why in TV and films it used more for atmospheric effects. Higher temperature lights have more spectrum of color to them, they look more true white on camera. Going back to our hardware store, look at any box that attempts to explain the difference between warm and cool 60-watt lights. The image of the cool always looks more white and pleasant than what you experience in your bedroom when suddenly you have an ungainly blue table lamp. A camera will only ever pick up so much complexity in an image, even ultra-high definition cameras are not as complex as the human eye. The artificial blueness we see is not always picked up on camera.
This is important to understand when you’re choosing a light source for your web camera. Many models of LED panel lights have what they like to refer to as adjustable color temperature. This tends to attempt to reproduce a range usually from 3000-5200K. Because they are compact and digital, these measurements can be highly subjective. However, it’s important to note that this range is small when you look at the available range. A 2200 swing is minor. For your daily web meeting, you will almost invariably notice that you will be happiest with the presentation 5200K gives you over the low end.
Brightness
As a concept, brightness is pretty straightforward. The higher you slide your wall dimmer switch, the more light comes out. However, there are a host of details to pay attention to when choosing the right light for your web meeting. Sticking with our hardware store shopping spree, you will see that the various light bulbs will equate wattage with a brightness (often lumen) number. In traditional incandescent lights it was easy to choose your light bulb based on watts. But a watt is an electrical measurement of the energy used NOT brightness. Brightness is measured in lumens. What is a lumen? Well, the dictionary definition is “The SI unit of luminous flux, equal to the amount of light emitted per second in a unit solid angle of one steradian from a uniform source of one candela.” Clear as mud, right?
In the simplest possible terms, lumens are the total amount of light created by a light source. This applies to a total area. So the higher the lumens, the more area will be illuminated. You’ll see another fun little word in our dictionary definition up there, “candela.” Candela is the measurement of light at a specific angle. This is relevant to our needs here because it measures the amount of light your source is creating focused at your face or whatever you are broadcasting.
Always remember, these numbers are when the light source is at full power. If you are unsure how bright you need your source to be always round up and have a dimming source. You can always make a light less bright but not always brighter.
One final note on brightness. In a traditional incandescent light you will notice that the more you dim down, the more orange the light becomes. This goes back to our section on color temperature. When you dim these lights you are cutting off electricity and thus heat generated by the filaments. So, you can, if so desired, change the color of you light by dimming, this is called “red shift.”
Angle
The angle of the light is what we’ll look at last. The angle of the light source can have outsized effects on what your web camera sees of your face. You, or whatever you are presenting are not a flat surface, thus you make shadows. Good lighting angles will help to offset any bad shadowing. Do a simple experiment, take a flashlight, keeping it about 8 inches away, shine it directly onto the palm of your hand. Now move the light slowly to the left and right while keeping you palm in the same place. See how the ridges and lines of your hand create shadows? You could even say that it creates an ambiance on your hand. Now, if you were to add a second flashlight to this experiment and shine it from the opposite angle you would balance out those shadows and create depth. You could even go a step further and add a flashlight from behind to finish off all three dimensions. This is the very basis of theatrical area lighting. If you were to walk up on a stage and stand in one spot during a play you would see various lights all pointing at you from multiple angles.
In conclusion
For most web meetings people don’t really think too much about lighting. But for the best presentation it is important to know where and how your face is being lit. If you’ve tried to use Zoom’s virtual or Team’s blurred backgrounds only to have it cut your face into tiny pieces this is because there wasn’t enough light focused on your face for the program to know what was you and what was the treadmill behind you. You want to present yourself in the best possible way, which means you need the best possible light.
