Categories of Light
All light can be divided into categories based on the type (source), the intensity, and the direction. One of the most basic divisions is between natural and artificial light. Another is hard versus diffuse (soft) light. A third set of categories distinguishes the direction from which the light is coming, which it also determines where highlights and shadows will appear in the image. Side, frontal, and back light are a few examples of direction. But, before diving into specifics, it's important to understand the relationship of these categories to one another.
Natural Light
Natural light is the best type of light for many photographic situations. In fact, the broader goal for many photographers using artificial light is simply to emulate the qualities of natural light. One positive note on natural light: no batteries needed. It's available anywhere you go and, apart from the subject matter, it's probably the quality of the natural light that drew you to the scene in the first place. In short, the one reason why natural light looks so good in images is that it is natural.
As previously noted, natural light comes from the Sun (or other "suns," in the case of starlight), and each type of natural light has its own qualities:
- Full, midday sunlight versus early-morning or late-afternoon
- Open shade
- Overcast skies
- Sunrise or sunset
- The deep blues of twilight
- Moonlight
- Starlight
- Window light
- Reflected sunlight, both soft and hard
- Daylight illumination from a frosted skylight
- Other natural sources not from the sun include firelight and lightning
Natural light can also be great for photos of people, though it may sometimes prove more difficult to use because it requires careful planning and observation. It takes more skill to find the ideal natural light for the idea, emotion, or mood you wish to convey.
Learning to evaluate and take advantage of natural light will dramatically improve your photographs.
Taking Advantage of Natural Light: Time of Day
Please review the following images closely. Pay close attention to the shadows, highlights and feeling of depth created in the photo of the woman at 7:45 a.m. as compared with the picture of her at 7:00 p.m. The light used in the earlier image (7:45 a.m.) helps create more depth in the scene, and it helps provide the perception of more space between foreground, middle ground, and background. In the later image (7:00 p.m.), the light is not helping to create more depth. Spatially, the scene is "flatter" in terms of contrast, and thus has less depth.
Landscape photographers are known to use the warm colors and long shadows of morning light. This can create more drama in the landscape, which may better represent the land itself. If you search for landscape images in magazines and calendars, you will find many examples of dramatic light achieved in early-morning hours. You will not see many landscape images made in midday light, because the increased contrast, lack of visual depth, and (unsaturated) colors are not what the photographer thought would best describe the scene.
Obviously, this is a generalization, but as you pay close attention to the thousands of images you encounter daily, you'll likely notice trends in terms of the type of light used for different situations.
Taking Advantage of Natural Light - Disabling Your Flash
The one thing that can kill the ambience of natural or existing light is the on-camera flash. Though this is not as big of an issue when shooting in manual mode, semi-automatic and fully automatic modes (such as aperture-priority and sports modes, respectively) can trigger the flash.
The best thing to do is to turn off the flash in these modes. The camera is programmed to make a good exposure, and often that includes adding in some of its own light if it feels there isn't enough available light for a good exposure. In some cases, the flash is triggered simply because it has been fooled by the presence of dark tones in the main subject or the background. This goes back, remember, to your understanding of how your in-camera (reflective) meter works.
Nothing can destroy the subtlety and character of natural light more than camera's built-in flash. If you want to take advantage of natural light, learn how to turn off your camera's built-in flash.
Artificial light is any light that is not natural and depends on an external source of power. This could be your on-camera flash, external flash units or studio strobes, tungsten photo floods, an overhead light fixture, fluorescent lights in an office environment, streetlights, stadium lights, stage lighting for a concert, the twinkling glow from Christmas-tree lights, neon, and so forth. Like natural light, artificial light can fall under the larger category of existing or available light (in other words, light you do not bring to or set up for your subject).
You might decide to use artificial light for a variety of reasons, including:
- When you need maximum control of your scene by using studio light sources, whether they are strobes or continuous hot lights.
- When there is not enough natural light to make an exposure.
- When you want to preserve the quality of the artificial light as an element in your image, such as the warm yellow light from a corner lamp, the harsh overhead from fluorescent lights, or the colorful glow of stage or club lights.
Experimenting with different types of artificial lighting will help you understand how they influence the image and how your camera records them. The more you know about the qualities of light, natural and artificial, the better you can visualize and control the effects they bring. Being able to identify different sources of artificial light and their inherent qualities will go a long way in helping you predict how they will affect your photography.
Tungsten Lights
These are also referred to as incandescent lights. They are most often found in homes, and they are among the cheapest bulbs to purchase. However, they are much less energy-efficient, and they give off a good amount of heat. Light from tungsten bulbs can vary quite a bit in terms of brightness (25-watt bulb versus a 500-watt photo flood, for example), but this light is generally softer and warmer than fluorescent light.
Halogen Light
This type of incandescent light is more energy-efficient and produces a brighter, whiter light source. It is used in projectors, household lamps, some streetlights, car headlights, and continuous studio lighting (also referred to as "hot lights").
Neon Light
A true neon light will have an orange-red color and is filled with neon gas, through which a small current is passed, causing it to glow. What we know as neon signs, which may be a number of different colors, rely on other types of gases for their color. Though neon lights don't really provide enough illumination to be a light source for a broader scene, they themselves can make for interesting subjects or background material
Streetlight (Sodium Vapor)
Like neon lights, sodium-vapor lights use pressurized gas to produce light. You can identify sodium-vapor lights by their yellow illumination. If you take a long night exposure using street lamps as your light source, you'll notice this same, somewhat eerie yellow-orange glow pervade your image.
Artificial Light (continued)
In addition to ambient or available artificial light, there are a number of options with which you can have more control: namely, flash or strobes. Many digital cameras come with built-in on-camera flash units that may automatically pop up, ready to fire in low-light situations (depending on your exposure mode and camera make). As alluded to earlier, these are generally the least appealing light sources in terms of effect..
Off-Camera Flash
An off-camera flash is more useful and offers many possibilities for positioning the flash, as well as for using accessories such as a mini flash-softbox or bounce cards to modify the quality of the light. In order to use an off-camera flash, your camera needs to have either a hot shoe or flash sync connection.
Club or Stage Light
Amazing effects can be achieved with these multicolored directional lights. Stage lights in particular are extremely powerful, making it easy to isolate separate beams of illumination. Concerts make liberal use of such effects
Studio Strobes
These are lighting systems that run from a power pack that is plugged into a standard power outlet. They connect to your camera via a sync cord, a slave unit (a device where an on-camera flash triggers the studio strobes), or a wireless connection. Studio strobes offer the most versatility and control in how the scene is lit. Their power output can be varied at the power pack, and they can accept a wide variety of light-modifying accessories.
As far as studio work goes, for the new user, the main disadvantage of a strobe system is that you cannot see the effect that the light will have on the subject. You have to use a flash meter to determine exposure and take test shots to determine how well the lighting setup is working. Fortunately, digital cameras provide instant feedback without the need for costly Polaroid tests.
Lightboxes and Studio StandsThere is a wide variety of stands and softbox types. If you plan to shoot on-location, size and weight might be an issue, and if you plan to keep lights only in the studio, maybe size is not such a big issue. More important, though, is the quality of light provided by the various light-modification tools. There are many different shapes of soft boxes and umbrellas, and they all produce a different quality of light.
Tungsten-Halogen Lamps
Some portrait studios still use hot lights for various reasons. There are advantages and disadvantage to both. In general, these are all terms with which you should be familiar, and this knowledge will help you choose the right lighting for any situation down the road.
Hard and Diffuse Light
We used the terms soft and hard light several times to describe characteristics of individual artificial light sources, and, in the case of natural light, qualities relating to specific times of day. Certainly, all light can be divided into one of these two categories, also referred to as specular and diffuse light.
Diffuse Light(or soft)
light is lower in contrast and more even. As a result, it is often easier to achieve a good exposure for both highlighted and shadowy areas, as the difference between the two is slight. Diffuse light can be very complementary for pictures of people where that person's likeness is the highest priority.
Diffuse light is either filtered through or bounced off another surface before hitting the subject. Open shade is one source of diffuse light. Other examples include: light filtered through a high canopy of leaves, the shady side of a building, or in the shelter of a doorway. Clouds, fog, dust, smoke, and smog are other environmental circumstances that can yield varying degrees of diffuse light, each serving to block or bounce the sun's rays. Window light may also provide very soft light, depending on the direction of the sun or how dirty the glass
Hard Light
Hard light is directional and generally more intense, thereby heightening contrast. It's great for building drama in a scene and emphasizing shape and dimension. Deep, defined shadows are characteristics of harsher light. Generally, hard light is used to illustrate an idea or concept, but it does not create a good likeness of a person.
Directional Light
The direction from which light hits your subject can have dramatic impact on your shot. Side lighting, for example, is quite effective at sculpting a subject, throwing long shadows, bringing out details, and adding a powerful flair. Backlit scenes can also be dramatic, with the light coming directly towards the camera, creating stark outlines of foreground elements or rendering a subject to complete silhouette. Frontal light tends to "flatten" a subject by minimizing the distance relationships between foreground and background and eliminating shadows that would otherwise give a sense of dimension.
The direction of light can also be used to slim a face or make a face look more full. For example, if your subject has a round face, you can use side lighting to give the perception that the subject's face is not as round. For a thin face you wanted to make a little fuller, you could use more frontal light. The best thing to do is try many different combinations to see what you like and in what situations.
Directional Light (continued)
Additional possibilities, though seldom used, as they are less flattering, include lighting a subject from above or below. Yet, even these have their uses. Lighting a subject from above may reference police questioning or interrogation, or even the sun at midday. Lighting from below may conjure the feeling of telling ghost stories around a campfire, with the story's narrator holding a flashlight under his chin for eerie effect.
In addition to the direction of light, you can also play with how this relationship changes when your subject is not facing the camera, but instead facing away, or into the light.
