Chapter Fifteen: Adding Illumination
We use a number of tools to manipulate and capture light; that is the essence of photography. The challenge is primarily in being able to identify the important components of light, roughly quantify them, and then manage them to contribute to the final image. Studio shooting offers a (generally) consistent environment, so spending initial time there evaluating the lighting and adapting it is much more feasible and simple than in the situations encountered by photojournalists, sports photographers, or birthday-party photographers.
Characteristics of Light
Amount
There are simply too many ways to express this characteristic of light. In the living room, we tend to express the amount of light a bulb can produce in terms of watts, which is incorrect: a watt is the measure of the amount of electrical energy consumed in the process. The more accurate expression of the amount of light produced would be in terms of lumens: an incandescent bulb that consumes 75 watts of electricity produces about 920 lumens of light, whereas a 25-watt compact fluorescent light bulb puts out around 1700 lumens. One of the older methods of expressing illumination is candlepower, with one footcandle equal to 12.6 lumens. I just saw a 40 million candlepower portable searchlight listed at Amazon.com: that’s just over one-half billion lumens.
Intensity
At noon on a cloudless day, with a clear sky and relatively low humidity, the summer sun can be quite intense. Direct light from any source can be intense, even if not as strong as the sun. For photographers, intense lighting is seldom beneficial, so we look for ways to tone down the intensity. That can be as simple as exploiting available features such as trees, walls, and awnings. We can also use more sophisticated devices, such as scrims and reflectors, especially the portable, collapsible reflectors. Most reflectors also have a sheer or translucent panel to greatly soften the light.
Color
The color of light varies with the source, the environment, and the time of day. One of the problems with incandescent lighting is that the color of light changes as the bulbs age; color will also vary with the voltage. A 3200 Kelvin, 120-volt incandescent bulb is going to be a bit yellow if you have only 110 volts to feed to it (the insidious part of this is that when you plug a 500-watt photo flood into your already-loaded circuit and turn it on, the voltage may drop appreciably, even further shifting the color toward yellow). Fluorescent bulbs may look alike, but the color of any given bulb depends on the environment it is intended for: office, bath, kitchen, etc. Sunlight pouring through the windows of a room with pink walls will be different from sunlight in the room down the hall with grass-green walls. The color of sunlight at dawn or dusk is different from that of sunlight at noon. The color of sunlight coming through glass, even “clear” glass, will change. Of course, air pollution also has a way of changing the color and intensity of light. One of the larger problems that we humans have with the color of light is that we tend to see it in comparison to other colors in the same scene, not as an absolute value. The camera, though, sees light at any one place as a Kelvin value. Recognizing and correcting the color of light perceived by the camera takes a bit of practice (though there are some very good—and expensive—meters available to help with this), and the right color correction will make a great deal of difference in the final image. It’s also easier to do it in-camera than in Photoshop.
Direction
In terms of aesthetics, direction may be the most significant of the qualities of light. Can’t move the light? Then move the camera! Think in three dimensions. With film, which was much “slower” than our digital sensors of today, we learned to pose our subjects looking into the sun, with us between them and the sun. The result was often a decently lit exposure of a grimacing, squinting subject, assuming the subject was not a field of corn. Even then, the photos were usually rather flat, or overly two-dimensional. Any shadows that could have helped communicate that third dimension were hiding out of view, behind a well-lit ear, cheek, or other element of the subject. And that’s still true today, if you use the straight-on approach to lighting, whether it be lighting by the sun, studio lights, or a camera-mounted electronic flash. Just having your subject turn a few degrees to the left or right does not help with this problem. However, if you move the camera as well, you’ll have enough side-lighting to greatly improve the perception of depth. Of course, if you’re working with portable illumination, then you can simply move the light source to accomplish this same objective.
Continuous Lighting
Natural
Natural lighting in its simplest form is daylight, either direct or indirect. Direct sunlight too often produces images with a narrow dynamic range, blowing out the highlights on light-colored surfaces and, at the same time, creating strong shadows that obscure details. There are a few techniques for helping with this situation (find some shade!), and there are a number of devices that can soften direct sunlight. Some of the best natural lighting comes from sunlight reflecting off of a soft-colored wall, bringing a bit of that color with it to your subject.
If you do portrait, glamour, or botanical photography outside, you should be looking at collapsible reflectors, which can help redirect some of that light to help compensate for strong shadows or, with a translucent fabric, soften the direct light. Most also come with gold, silver, or a mix of gold and silver reflective surfaces that allow you to introduce some degree of warming light.
Natural light isn’t always sunlight. It could be moonlight or a flash of lightning.
Man-Made
Man-made continuous illumination would have to include both intentional and unintentional sources. A portrait illuminated only (or primarily) by a campfire would be an example of intentional man-made continuous illumination, as would a photo of a midway illuminated by hundreds of different-colored neon and incandescent lamps. Of course, any image illuminated by one or more lamps—be they street lamps, automobile headlamps, retail-store overhead fluorescent lamps, or the incandescent lamps of a residence—is using an intentional man-made source of continuous illumination. For photographers, the most common source of intentional man-made continuous illumination is probably their banks of studios lights.
Unintentional lighting sources might include the inferno that illuminates the blackened, sweaty face of a firefighter, or the birthday candles that illuminate the radiant smile on the face of a four-year-old.
Flash Illumination
In the early 1950s, my caving friends and I found ourselves in some rather large but totally black spaces—that’s just the way some caves are. With a few rolls of hot color slide film (ASA 25), we would put a Leica IIIf on a tripod, set the aperture to f/11 to get decent depth of field, and set the shutter to stay open until we came back to the camera to terminate the exposure. While the shutter was open, we would walk around with a flash gun, manually triggering a flash bulb here, one there, another elsewhere, until we had “painted” the entire room with light. It was a task that might require in excess of a dozen flash bulbs for a single exposure. Since we were part of the “take only photographs; leave only footprints” school of nature conservancy, that also meant a load of flash bulbs came out of the cave with us.
One day, we ran across a small reel of metallic ribbon at a chemical supply company and decided to experiment with it. The metal was magnesium, and the ribbon was about 1/8 inch wide and .001 inch thick. We would cut 8-inch pieces off of the 75-foot reel, form a “hook” on one end of each piece so that we could hang them inconspicuously, and distribute them around room. When the camera was set up, we would ignite each ribbon with the flame from our carbide lanterns. That much ribbon would produce about eight seconds of illumination, and at about 3500 Kelvin, it worked with our slow color film beautifully. It was an effective and reasonably inexpensive means of lighting those large rooms. We considered using flash powder, but couldn’t find any of the old guns used for triggering the powder. Nor did we want to be breathing the volumes of smoke released by flash powder. Then “strobes” became available to photographers. . . .
Strobes
Fifty years ago, all electronic flash units were referred to as “strobes,” reflecting the fact that our photographic units were derived directly from these multiple-flash/short-duration units. In photography, we crippled the ability to release multiple bursts of light in favor of a longer, single burst in our effort to crank out a greater quantity of light. It’s surprising to see how many folks still use the term “strobe” to describe the electronic flash—speed light—that they use with their camera.
True strobes are still available, and many of the upper-tier speed lights have a strobe capability built into them. The photographic use for a strobe almost always involves our need to capture several images depicting some form of motion, all in a single photograph. A typical application might be creating a single photograph of a golfer showing a dozen or so captures of his swing, from beginning to end. Another might be such a sequence showing the different stances of a dancer as she progresses across a stage.
Speed Lights
Electronic speed lights have certainly evolved over the past half century. My first speed light was a home-built unit, but it pretty well matched the functional capabilities of the best commercial units. However, the need to keep a 400-volt battery ready, and to deal with two capacitors, each the size of a 12-ounce can of soda, was a bit much. It didn’t travel with me too much. Now I can get a small, extremely portable Canon Speedlite 90EX for $150 that produces more light and offers features that my old speed light didn’t. The Canon 7D, 60D, and a couple of recent Rebels have small electronic speed lights built into the camera and that are capable of serving as a flash commander, optically coordinating dozens of remote Speedlites distributed across as many as three groups.
In today’s world, it’s difficult to imagine the typical digital camera without some kind of electronic speed light. And these speed lights have become so “smart” that they can often set themselves for mainstream automatic shooting, but also provide an extensive list of customizable options for personalizing your photography.
The latest in remote speed light utilization is radio-controlled master and remote units. Until recently, these units relied on encoded bursts of light for the camera-mounted commander to communicate with the remotes. Such an arrangement required that the commander be in the line of sight of each of the remotes. Using light for this pre-flash communication also meant that human subjects might well react to the light and have their eyes squinted shut by the time the true flash was triggered. In a radio-controlled speed light configuration, there is no light used for communications, so the remotes can be placed anywhere within the operating range of the commander, without regard for drapes, walls, furniture, or any other visual obstruction. Both the optical and the radio-controlled systems allow for extensive arrangements of remotes, with up to three different groups of remotes supported in optical systems, and as many as five groups supported when using 2012-released Canon cameras using radio control. All remotes in a group are treated identically, but each group can be individually configured, which provides a significant level of lighting control.
As of the summer of 2012, Canon lists the 90EX, 270EX, 270EX II, 320EX, 430EX II, and the 600EX-RT Speedlites on their website for general photography, in addition to the MT-24EX Macro Twin Lite and the MR-14EX Macro Ring Lite. The two macro Speedlites are designed to encircle the lens and be able to work close to the subject. All but the 270EX are also capable of functioning as a remote unit (referred to as a “slave” unit by Canon) when managed by an optical-transmission commander unit (referred to as a “master unit” by Canon). The 90EX, 600EX-RT, and both macro Speedlites can function as both a Speedlite and an optical commander unit when attached to the camera’s hot shoe.
The recent 580EX and 580EX II Speedlites are also capable of serving as a dedicated external Speedlite, remote unit, or functional Speedlite and optical commander unit.
With the exception of the 600EX-RT, these units all rely on light to communicate between a commander unit and any remote units. The 600EX-RT has the ability to use either light (optical) or radio transmission for that communication. Using only light for a commander-to-remote communication is significantly less expensive than using radio transmission, but there are some disadvantages:
• There must be a line of sight between the commander and the remote; anything that blocks the light will interfere with that communication.
• The effective distance between the commander and the remote is limited to about 50 feet indoors and 30 feet outdoors (compared to about 100 feet indoors or outdoors for radio transmission).
• A maximum of three unique groups of remote units is supported, although each group can have an unlimited number of remote units (all units in a group are treated the same, but are not required to be of the same model).
• Canon DSLRs in the 1D series and the 5D series do not have built-in flash units, and only a small number of other models have a built-in flash that can also function as a commander unit. Thus, for many users, some kind of commander unit must be attached to the hot shoe: either a Speedlite capable of also functioning as a commander, or the ST-E2 Speedlite transmitter. The transmitter is a commander only, and has no electronic flash output.
• The encoded light flashes used for communication occur just before the main flash and can lead human subjects to conclude that the picture has been taken, allowing them to relax just as the main flash is triggered.
• At the moment, the variety of radio transmission–based Speedlites and accessories is quite limited and a bit expensive. The 600EX-RT is the only Speedlite available at the moment, and the ST-E3-RT is the sole transmitter unit available. The 600EX-RT can serve as a dedicated external flash, an external flash with optical transmission commander capabilities, an external flash with radio transmission capabilities, a commander with either optical transmission or radio transmission capabilities (without flash output), an optical-transmission remote, or a radio-transmission remote. The ST-E3-RT serves only as a radio transmission commander, and must be attached to the camera’s hot shoe for full benefit.
On the left of figure 15-1 is the Speedlite Transmitter ST-E3-RT, and on the right is the Speedlite 600EX-RT. This view masks that the LCD panel for the flash is on the back of the unit, whereas the LCD panel for the transmitter is on the top of the unit. Note the similarity of the user interfaces for these two units. In the upper-right corner of the transmitter unit’s graphic, you will see an icon representing a radio antenna with concentric circles, while the graphic for the flash unit shows an icon for a lightning bolt, representing the optical transmission mode.
Please note that not all countries have the same regulations and specifications concerning radio frequencies and types of communications. In fact, Canon provides you with a list of countries yet to approve the use of this radio transmission technology (and some already have conflicting implementations, so there will never be approval to use this equipment in those countries). The regulations extend to you and your travels: you have the responsibility to determine whether you are allowed to use this equipment in those countries. Canon also manufactures the 600EX for use in those countries that have not approved the use of the 600EX-RT. Its major difference is that it supports optical transmission only. Be careful: I’ve seen too many reviewers and bloggers who seem to think they can call the 600EXRT the “600EX,” obviously not knowing that a bona fide 600EX exists, just not in the United States. I would not be surprised to see Canon lop a three-digit number from the price of the 600EX-RT and introduce the 600EX here as well.
Cameras released after January 1, 2012 (EOS-1D X, EOS 5D Mk III, EOS Rebel T4i) have a new hot shoe that allows a greater degree of communication and control between the camera and the attached Speedlite or commander unit when using radio transmission.
Among the advantages:
• The ST-E3-RT Instruction Manual states: “. . . you can shoot without any restrictions on the flash mode and maximum flash sync speed.”
• With these cameras, you have the ability to shoot with a different flash mode set for each firing group (ETTL-II for one group, Manual for another, Auto external flash for yet another).
• The modeling flash can be triggered from a remote unit.
• You can release the shutter from a remote without the need for any additional cables or remote control units.
• You can set the functions for Radio Transmission Wireless Shooting in the camera’s FLASH Function Settings screen in the SHOOT1 menu (earlier cameras require use of the transmitter to set these functions).
• High-speed sync is available for these cameras, but not for earlier cameras.
Compared to its predecessors, the 580EX and 580EX II, the 600EX-RT has improved weather protection, a greatly improved hot-shoe latching system, a far simpler user interface, a quieter recycle, a bit more power, and—of course—the radio transmission system.
With radio transmission, the sum of transmitter and Speedlite units must be 16 or less, including the unit in the camera’s hot shoe. However, in GR (Group) mode, you now have access to as many as five groups, allowing even better control over the functions of remote units.
Figure 15-2. On the left is the EOS 5D Mk III with the Speedlite 600EX-RT mounted, and on the right is the camera with the Speedlite Transmitter ST-E3-RT mounted in the hot shoe.
