10: Lighting

1) Size of Light Source

The effective size of a light source determines the sharpness of the shadow an object casts. A small light source will cast distinct shadows with hard edges. This is called hard light. The sun is a handy example of an (effectively) small light source. You have seen the shadow that you cast when the sun hits you. It is dark and the edges are distinct with sharp edges. 

Another small light source is a flashlight, which is effectively about the same size as the sun (much smaller but much closer). This light will cast very similar shadows as the sun.

What if the sun goes behind a cloud, or it is an overcast day? The sun is no longer lighting the scene directly, and it is now the sky that is the effective light source since the sun itself is blocked. The sky is a very big light source, so the shadows are very soft and indistinct. This is called soft light.

The quality of the shadow cast by a light source is very important and extends beyond just the shadow you see. The way texture is perceived largely depends on many small shadows on the surface of the subject. Since small light sources produce distinct shadows, they show texture much more readily (see illustration below).

This is the reason portrait lights are always bounced off of umbrellas or filtered through material—these things make the effective light source larger and so reduces the texture of the skin, which is made up of not only big pimples but many smaller irregularities that would be exaggerated with the sharp shadows of a small light source.

Reflections are also more distinct with a small light source (look closely at the lemons on the previous page). Everything is reflective to some extent, and the reflections help to determine how something looks. This is the reason that actors and newscasters get their faces powdered before being on camera. The powder reduces reflections from various parts of their faces. You are accustomed to seeing these reflections when you speak to someone and so do not notice them. The camera is not so kind.

2) Direction of Light Source

Also influencing reflections and texture is the direction the light is coming from relative to the subject and the camera.

Hard light (from a small source) coming from near the camera will show less texture than light raking across a subject. Another way of thinking about this is that the shadows from the light near the camera are smaller, so less noticeable than the longer shadows of raking light extending across the subject.

Reflections from light coming from near the camera will be also be more noticeable since the light reflects back at the camera. You may have noticed this with flash pictures of friends, especially if their skin is not freshly washed (if it is oily). The flash is a small light close to the camera, so the reflections from that oily skin are exaggerated.

There are other things that change when the direction of the light changes. The following are some examples: 

The classic way to scare the bejeebers out of little kids is to hold a flashlight so that it points up at a face. In natural settings light is rarely seen coming from below, so it scuttles expectations and causes anguish (well, at least to little kids).

Light coming directly from the direction of the camera (think flash, license photos, and mug shots) is rarely pleasant since shadows that define features and give faces volume are hidden.

When the light source is small, light from straight above a subject (like a noon-day summer sun) is also unpleasant. With people it causes a shadow covering both eyes and large shadow under the nose (like Hitler’s mustache!). With other things light from above is not as objectionable, but certainly not inspired lighting or particularly interesting.

Light from behind the subject (called back-light) is great for some things, since it is unusual. But many times it is useless since it does not reveal the subject.

This discussion leaves only one light direction option left—light from the side. With a hard light (small source), this lighting can be very dramatic. With soft light (large source) it can be very pleasing.

Of course, light from any direction can be effective if it is used well, and light used by photographers often doesn’t come strictly from one of these directions—it may come from the side, but also up and toward the camera. Or a hard light from almost behind the subject, illuminating just a sliver of it. The dome of the sky lights from many directions at once. 

Also, one light is often used in conjunction with other lights, although one light source can be very effective as you can see from the examples on the next page.

3) Number of Light Sources

More than one light is almost always used with any photograph. Imagine a snapshot on a sunny day. There is the sun (a hard small light) hitting the subject, but there is also the dome of the sky (a soft big light) also hitting and illuminating the subject. What the photograph reveals is a combination of these two light sources.

The secondary light sources can be subtle. On a snowy overcast day, the light source is the sky, but the reflection of the light from the snow acts as a second large (soft) light source giving the subject almost 360 degrees of illumination.

Many times (either in nature or with lights indoors) two light sources are needed, if only to fill in the shadows to give them tonality and detail. These light sources can be reflectors reflecting the main source (the sky is actually a big reflector for the sun), or actual lights themselves.

Of course, this doesn’t mean you have to carry reflectors and lights around with you. Nor do you have to think about all of this as you photograph. Just be sensitive to the light. Really look at it. 

Size, direction, and number of lights are the three things that influence how light looks. It may seem pretty simple, and in its basic form, it is. But there are many permutations that can complicate things. What if you have a light reflector with a faceted surface? —Is it one large light or many small lights? Or a soft light coming from both the side and in front of the subject? Things get complicated pretty quickly because all of these variables of light are actually continuums that work together.

One could argue that there are other variables, such as how coherent the light is. This might describe how a matte reflector makes different kind of light than a polished reflector. But these are subtleties outside of the range of this text.

What follows are several issues with lighting. Although these things are not part of the variables of light, they do influence how you use light.

The Color of Light

The color of the light hitting a subject doesn’t really have much to do with how a photograph looks—as long as the light contains the colors necessary to reveal the subject’s colors. You can always balance out whatever color there is or add any color you want. This was covered in the Sensor chapter.

In the context of the current chapter, the color of light is important when you have multiple light sources of different colors, which is called mixed light. For instance, if there is a window illuminating half of a subject and an interior light illuminating the other half. The window side of the image will probably be blue compared to the interior incandescent lighting the other side of the subject. 

This is not a problem if you want your photograph to be half blue tinted and half orange tinted. But if you want the color to look natural, you have problems. There is no real solution to this other than changing the light situation, although it can sometimes be improved in an image editing program that allows for local controls.

Also watch for light reflecting from color objects. If sunlight is reflecting off of green foliage to illuminate a side of a face, that side of the face will be greenish.

More about Reflections

Every surface of every thing reflects light. Some surfaces, such as a mirror, reflect this light directly and coherently enough to reconstruct an image of what it is reflecting.

Other surfaces, such as a shirt, reflect the light in a much more scattered fashion. This is why we admire ourselves in mirrors, not in shirts. The light reflected from a shirt is too scattered to reflect an image. 

Dark objects reflect less light than light objects (of course). This is a good thing, because it is what photography relies on to make an image!

Whether it is a mirror or a shirt, light reflects off of a surface at the same angle from which it hits that surface. You can easily see this when you adjust the side mirrors in a car, but it is a little difficult when applied to objects which are less shiny. 

Objects that are not flat like the painting shown on the previous page also reflect light in the same way, although it is more difficult to readily see because of the curves of the object.

In practical terms, what this means is that you should watch for where the light is coming from and discern how the reflections are influencing the interpretation of the scene.

Reflections can help define an object or they can obscure it.

Light Falloff

Light gets dimmer the farther from the source it is. Of course you know this, but it is important to keep in mind. With a light source like the sun this is not an issue. You don’t have less light if you walk away from the sun—the distance you are moving is infinitesimal compared to the total distance from the sun. But if a window (or a candle) is lighting the scene, suddenly the distance at which the light gets dimmer is very important.

Portraits

Since you know something about photography, at some point you will be asked to take a portrait.

There are many ways to light a portrait. From this chapter you already know that you are probably going to be looking for a soft (large) light sources.

The question you need answered is how the portrait will be used. With the common portrait lighting set-up shown below there are two lights set above and to the right and left of the subject. One of these lights is called the main light, and does the primary job of illuminating the subject. The other of these lights is dimmed (or moved back) to provide about one stop less light than the other to illuminate the shadows. This is the fill light. 

You can also add a third light for controlling the brightness of the background. This is called a background light (of course). Other lights can be added, such as hair lights pointing towards the camera to illuminate the side of the hair to give extra highlights and depth. 

The standard portrait situation depicted in the illustration here is only important as a point of departure. It serves a purpose, but the most interesting portraits depart from it quite a bit. See the photographs on the next page for proof of this. 

Copying Flat Material

There may be situations where you need to photograph flat material, be it paintings you did in kindergarten or family photographs that need digitizing.

There are two directives related to this. First, the material needs to be as parallel as possible to the back of the camera. Second, the lighting needs to be as even as possible without reflections. If you just take a photograph with the flash on the camera, the light will bounce right back to the camera and the image will probably be washed out by reflections.

A copy stand is made for copying flat things, and ensures these requisites will be met. Without a copy stand you can improvise. Perhaps by copying the material on a porch where the light is coming from the side. Or by using a window that is to the side of what you are photographing. 

There are further instructions contained in the appendix of this book.

Light Types

Light originating from the sun is called natural light. It is wonderful source, whether it is coming through a window, reflected off a wall, in the shady area next to a house, or even shining directly on the subject. Ambient light, or existing light, is light that happens to be around. Maybe a living room light, or the fixtures in a ceiling, or natural light.

Ambient light can be fine, but also can be awful. There are times when you need lights made for photography. What follows are the main types.

BUILT IN FLASH: Your camera’s built in flash is not a controllable light. It is small (hard), and it comes from only one direction (not an ideal one). It is also only good for illuminating things close to the camera. But it is convenient when you have to have a bit more light, and you can even turn it on outdoors when you need to lighten the shadows in a scene.

CAMERA FLASHES: These are bigger flashes which mount on your camera. They put out much more light for longer distances, and can be aimed to bounce the light off of a ceiling or wall. Often you will see these being used with various reflectors to split the light so that part of it can bounce and part be directed to the subject. These flashes often integrate into the camera’s automatic controls.

Many flashes can also communicate wirelessly to additional flashes, which can be set around in an environment and bounced or aimed through translucent boxes (soft boxes) which increase the effective size of their light source. With multiple flashes, lighting options increase substantially. You can have a lot of control using multiple camera flashes. 

MONOLIGHTS: More light can be had if that portable flash is made bigger than a camera flash. These larger flashes, called monolights, also have modeling lights, which are extra (incandescent) bulbs that contribute nothing to the exposure itself, but allow you to see the effect of the light before you take the picture.

Monolights are very simple and versatile. Although the size dictates that they be used on stands, most can be powered by a battery, so some portability remains. 

Monolights have wireless connections to each other and to the camera so that they are all triggered when the shutter is open. You can buy monolights in kits that come with stands, reflectors, and a wire-less transmitter to mount on the camera.

STUDIO FLASH: These are more powerful than monolights, so the power source needs to be separate from the light itself. These lights have power packs to which multiple light heads can be connected. With digital cameras the extra power these lights have is rarely necessary considering the cost and weight of them.

HOT LIGHTS: These lights are like desk lamps, but they can be mounted on stands. They are brighter, smaller, and more predictable in their color. They are constant-source (don’t flash), so can also be used with video. The better ones all use halogen lamps, which do get very hot.

There are many types of hot lights, from spotlights to ones with built in large reflectors.

LED LIGHTS are basically the same as hot lights, but with less heat. Like hot lights, these are constant-source lights. LEDs have many advantages over hot lights. Not only do they stay cooler, they are extremely versatile and come in forms from panels to rings. They can easily be powered by small batteries, they have good color, and with some the color can be varied to match either daylight or incandescent. They can be made very small, and multiples of them can be put together to make large fixtures. 

As LED technologies get better, these lights are largely replacing hot lights.

Light Modifiers

If you want to make a big light out of a small one, just bounce it off of a neutral colored wall or ceiling. If you want more versatility in modifying light, you could buy a sheet of white cardboard (or foam core) or cover a surface with aluminum foil. If you have enough duct tape you will be amazed at how easily you can modify light sources. And, if you can make it, you can surely buy it—there are any number of things sold to modify light sources. What follows are two which are widely used and very practical.

UMBRELLA: Photographic umbrellas look very much the same as the rain variety, but with white, silver, or translucent interiors. You simply mount your small-source light so that it points to the concave part, and the light is reflected out as a nice large-source light. These are very portable and retain much 
of the brightness of the 
original light. 

SOFT BOX: Put a box over a light and shine it through a translucent bottom. Soft boxes act much the same as umbrellas in making small light sources big ones. They have some disadvantages over umbrellas, such as the fact that they block more light, making the light dimmer. But they also have advantages, such as a making the light more controllable, especially when you take into account that they come in many sizes and can be used with accessories to tailor the light. 

With most LEDs putting out comparatively little light to begin with, soft boxes work best with flash. You could try a hot light in one, but get the fire extinguisher ready before you do. 

OTHER LIGHT MODIFIERS: There are a myriad of different accessories that can be made or bought to modify light. Reflectors with different textures can make the reflector act like multiple tiny lights. Adjustable doors, louvers, or flags (cards) limit the light spill and direct the light. Translucent tents can contain small subjects and soften the lights placed outside the tent to make a 180 or 360 degree light source.

Often photographers use duct tape (or black gaffer tape) and various cards and reflectors to modify the light for specific instances. Lighting might seem very complicated, but often lights are only added as needed to do things such as lighten shadows or provide highlights.

Now Go Shoot

Evaluate the light source as you are taking photographs. Small or large? Is there more than one light source? Are reflections making additional light sources? What direction is the light coming from? Try different directions. How are these things interpreting the subject?

Turn your camera flash on and try a few comparisons with and without the flash. Try to use the flash when photographing closer things outside.

How good is a desk lamp for taking photographs? Turn off all the other lights in the room and try it. How about a window? 

Take a sheet of paper and reflect some of the light from your small light source (sun or desk lamp) back to your subject to fill in the shadows with a smaller subject. How does this work with a large light source?

EXPERIMENT

Find a simple object with a textured surface that you can carry around or that will go where you tell it to go. Place it in different lighting conditions with a fairly neutral background so the difference in lighting is the main change. Find at least eight different lighting situations (light size, direction, number of lights).

One common object for this experiment is an egg. While an egg does show quality of shadows and reflections very nicely, you do have to look closely to see texture changes. A vegetable or your hand might be better. Try to make this experiment somewhat practical and remember that this is just an experiment that will show you a bit more about light. High art can come later.

And if you are really interested, you can take this experiment and expand upon it, using multiple lights you might have handy and reflectors made of sheets of paper, boxes, and whatever else you can find.

One Last Note on Lighting

Lighting with photographic lights can get somewhat complicated and has a tendency to wait for that unbought light. Again, remember that the natural light that is around you all the time is an excellent light source. In other words... 

Keep it Simple

At right is a composite image of a broken cup. Several thousand photographs were taken for this on a porch with natural light, and as the shooting progressed clouds came and went and the sun moved across the sky. 

Because of this, there were a range of different colors in the image. These had to be separately color balanced for many groups of the images.

That was a lot of work, and would have been unnecessary with a more controlled light source. But it was much more pleasant to take the photographs on a nice day outside rather than in a dark studio.

Also, since the shadows necessarily changed color relative to the highlights, a certain amount of randomness was introduced, making the image a little less formal, which in this case is a good thing.

Lighting Questions

What are the three main variables of light?

Hard-edged shadows would indicate what kind of light source? Soft-edged shadows?

What effective size of light source creates ‘soft light’. What size creates ‘hard light’?

Why does the sun behave like a small light source?

What type of light source makes reflections more distinct? Textures more distinct?

Mixed light refers to what quality of light?

What kind of objects reflect light? (trick question)

At what angle is light reflected from objects?

Why is the sun not giving you less light as you walk away from it?

How many lights are used for the common portrait situation given?

What is the main light in a portrait situation called? (this is pretty easy)

What device is made for copying flat material?

Light originating from the sun is called what?

What is the term for light existing in the environment in which you are photographing?

What is the type of flash is self-contained but must be used on stands?

What are two light types that have a constant light output (not flash)?

Photographic umbrellas are used to do what? Soft boxes?