It's the Light Stupid (Part One)

Every photo you’ve ever taken is just a record of one thing: light. It’s the invisible brush that paints every image, and if you don’t understand it, you’re not really photographing.

Many years ago, I was in a friend’s darkroom—a name that probably any film photographer would recognize—and there was a big sign on the wall that said, “It’s the Light, Stupid!” And so it is. As photographers, we have to be aware of so many things, all at the same time. However, in my view, there is one overriding issue that supersedes everything else, and that is light. In order to create truly compelling photographs, we must be aware of and have a clear understanding of light—what it is and what it does. We photograph light, not the object it is falling on. And that differentiation is very important to understand.

Light serves several functions in photographs. First and most obvious is the function of providing local and overall illumination. In addition to this, light also reveals form and texture, provides definition, and helps to set the mood of the photograph.

Before the days of digital, when we used film, we had to be aware of light energy that we couldn’t see because their wavelengths were in the non-visible range. These included ultraviolet and infrared light. An abundance of ultraviolet light could cause photographs to have an unpleasant violet cast and the appearance of a haze. Modern digital sensors have solved that issue to a degree. However, when I use color transparency film—AKA slide film—outside, I always use a UV-15 filter. So, though we usually can’t see UV light with our eyes, it is there and can have an effect on our image. It is outside the range of human vision. Infrared light is at the other end of the spectrum, again outside the capability of human vision. It’s interesting to note that some digital cameras can be modified to see IR light, which some people really enjoy and is an expressive medium for some, particularly in black and white.

For film users, there were films that were designed to see actual infrared light. Those films are no longer manufactured, and they were excessively difficult to deal with, requiring specialized filtration for exposure and specialized handling in loading and development to avoid fogging. There are contemporary IR films being made; however, they are not true IR films.

Most often, when we consider the possible solution to a photographic problem, the first thing considered is the quantity of light falling on, or incident to, the object or scene we are portraying. This is a valid concern, but once a proper exposure solution has been determined, there are more issues that should be dealt with. In fact, I try to deal with these other things before I determine an exposure solution since, in my view, they are sometimes the things that make a photograph effective—or can cause it to lose all visual appeal. Many times, we respond to an image emotionally before we consider these other factors. But remember, your camera doesn’t deal with or see things with emotions. That is strictly a human response, and the camera only sees things in an analytic way. As a result, we commonly come home, process the image—whether by the film process or a digitally processed image—and what we see in the proof print bears little resemblance to what we intended when the image was seen originally. I see this a lot, where the concept was strong, but the execution isn’t. So let me offer some thoughts on why that may be.

There are five things we have to be aware of about light: quantity, quality, direction, spread, and color. Allow me to explain.

Quantity

Almost everyone understands light quantity. And while the human eye is very incapable of judging the actual quantity of light available, we have light meters for exactly that purpose. Most modern cameras have a built-in light meter coupled with a computer that will give you the exact information needed to determine your camera’s settings to yield the image with the optimum exposure. Not only that, but digital cameras have a feature that isn’t available to those of us who work using film. That feature is the histogram, and it is an invaluable tool that I think too few photographers understand—and that fewer use.

Quality

There are basically two qualities of light: specular and diffuse. The more specular a light source is, the sharper-edged the penumbra will be. In other words, if the edge defined by shadow is very sharp, the light is specular. And we conceive that as having higher contrast. Usually, specular light emanates from a small light source; in fact, the smaller the light source is, the more specular the light is. A good example of that would be if you were standing in the desert at White Sands, New Mexico on a July day directly at noon, with the sun directly overhead and no clouds for a hundred miles in any direction. Another example might be someone standing on a performing stage being illuminated by a single source light at a great distance. Specular light is harsh in its quality and can be very difficult to manage, though some great masters of photography have used it to great advantage. Think of the work of George Hurrell or Yousuf Karsh. Both used very small and intense studio lights to illuminate their subjects.

The next quality of light is diffuse. Diffuse light has the characteristic of emanating from a larger light source. Usually, it is a much easier source of light to work with, and there are people who have made a career of using that quality of light. My friend John Sexton has a coffee table book of his work in which all the images were created using diffuse light only. In his book Quiet Light, he used photographs that were, almost exclusively, exposed either before the sun was up in the sky or after civil sunset.

In my studio practice, I almost always used a light diffuser that was 48"x48", so it was very large—thus rendering a soft light quality.

This was my most commonly used light source, especially for portrait work. Using it allowed me to work very quickly and accurately.

Diffuse light has the characteristic of being softer—the larger the light source, the more diffuse the quality of light will be. It is characterized by having a softer delineation between the shadow areas and the highlight areas. The guiding principle is that as the light source increases in size relative to the object being photographed, the softer—or more diffuse—the quality of light will become. On the other hand, the smaller a light source becomes relative to the object being portrayed, the harsher and more specular the quality of light will be. In a real sense, the addition of a diffuser to a small camera-borne flash has little effect other than cutting off the amount of light emanating from the flash unit. So all those silly little toys that people buy to diffuse the on-camera flash are just a mechanism to relieve you of your hard-earned shekels. All that is needed to change a specular light source to a diffuse one is to place a diffusion panel of some kind between the light source and the subject or to reflect the light from the light source off of a larger reflector of some type.

When I did large set studio work, such as automotive photography, I would take very large pieces of cloth—we're talking about feet of cloth, not inches—place them in front of a light bank, and then move the car or motorcycle until I got the reflection pattern I was looking for. BTW, moving the lights wasn't practical since they were fastened in a permanent position in the building. I remember that on one assignment I was photographing an AC Ford Cobra, and I had 20 electronic flash heads fastened in a light bank that was suspended above the floor from the ceiling by about 7 feet. I wanted the light to be longer than the vehicle by three or four feet and just high enough from the car so that it didn't intrude into the image. On another instance, I was photographing a Yamaha dirt bike, and that light bank was sitting on the floor close to the bike, but off-camera. It was 4 feet by 8 feet, so these were very large light banks—easier to move the object than to move the light sources. The object was to get long, unbroken highlight reflections that would describe the contour of the vehicle.

Diffuse light is, in my experience, the easiest light quality to work with if you are photographing the landscape, too. So, how does that work, since the disc of the sun is approximately 2/3 of an inch no matter where you are on the planet, or what time of the day, or day of the year it is, since the disc size of the sun is determined by its distance from the Earth? What happens is that at sunrise or sunset, the illumination from the sun will be reflected out of the sky opposite the sun. During pre-sunrise, the light of the sun emanates to the Earth's atmosphere above the object and reflects back to illuminate whatever it is you are portraying.

In this photograph, Cannon Ball Concretions, Teddy Roosevelt National Park, the sun hadn't yet cleared the horizon above this ridge, so even though there were no clouds in any direction, the quality of light was very diffuse. A few minutes later, the scene was a visual mess, and I would not have bothered to get my camera out of my backpack. So this type of light is always available either pre-sunrise or post-sunset. The other time diffuse light will occur for the landscape or outdoor photographer is if there happens to be cloud cover; and in my experience, that will allow a photographer to work easily as long as the cloud cover lasts.

Direction

The direction of light will allow you to organize your photograph in a way that is pleasing to you. Pay close attention to the direction of light. It is the direction of the light that gives dimensionality and shape, as well as texture and the feeling of depth to your photograph. It would seem to be a pretty obvious factor, and yet as I look at people's photographs, it becomes obvious that either a lot of photographers are oblivious to its importance or they don't know how to use it.

Here is an image I did for a bride several years ago using light quality and direction to show the details of her gorgeous wedding dress on her wedding day.

In order to cover this subject in a semi-detailed manner, and because I believe it is one of the most essential topics a photographer needs to understand, I will need to split this up into two writings.

So yes—it’s the light, stupid! Everything we photograph is merely a record of how light interacts with the world in front of our lens. Whether it's soft and diffused or sharp and specular, whether it pours in from overhead or glows gently from the horizon, light is the true subject of every image we make. Mastering photography means learning not just to see the objects before us, but to truly see the light—its direction, its quality, its quantity, its spread, and its color. Understanding these elements doesn't just help us take better pictures; it helps us tell better stories. In the end, it’s not the camera, the lens, or even the subject that defines a great photograph—it’s the light. Always the light.