What are the different types of studio lighting and what are the advantages and disadvantages of each type?
Electronic Flash Electronic flash is daylight balanced (5500K, or Kelvin) and can be used for almost any studio application. When lighting with electronic flash, the exposure is made by the discharge of a powerful micro-burst of light, which is generated by the power pack (or generator) and output through the flash's lamp head. Because the exposure is captured in a single, instantaneous and powerful flash of light, flash lighting is ideal for stopping fast-moving subjects, living and otherwise.
The power output of studio flash is measured in Watt-seconds (W/s). The least powerful electronic flash packs are rated as low as 100W/s, and the largest packs are rated at 6400W/s. Each time you double the W/s, you gain a stop of light, and conversely, each time you halve the W/s, you lose a stop of light.
Flash durations vary from model to model. Depending on whether the pack is set to full power or its lowest output setting, durations can vary from 1/100th-second (or longer) to micro-bursts as brief as 1/12,000-second.
Most electronic flash heads contain tungsten modeling lamps (usually 50W to 250W), which serve to emulate the look of the final flash exposure. The modeling lamp also serves as a focusing aid, since the flash tube emits light only at the moment of exposure. Unless you’re shooting at longer exposure times, the light emitted by the modeling lamp does not affect the exposure time (or color temperature) of the final image.
A big advantage of electronic flash is that despite the volume of light energy it outputs, with the exception of the relatively low level of heat created by the flash’s modeling lamp (which can be switched off as needed), flash does not create excessive amounts of heat, making it comfortable (and practical) for shooting portraiture or any other subject that would be adversely affected by excessive heat.
For controlling and shaping light generated by flash, photographers can choose from a wide selection of OEM and third-party light-shaping tools including umbrellas, light boxes, light banks, snoots, rods, Fresnel spots, flood heads and similar products.
Studio flash is available in two configurations: separate power packs and heads, and self-contained monolights, which consist of a power pack and lamp head combined in a single enclosure. Each configuration has its advantages and disadvantages, but both are equally effective for lighting up studio setups, complex and otherwise.
Most power packs accept two to four separate heads, each of which, depending on the make and model, can be adjusted symmetrically or non-symmetrically from full power down to small increments of power (infinitely or by click-stops) in order to create the desired lighting effect. As with most consumer electronics, computerized control boards are replacing the analog control panels that have traditionally adorned the top decks of power packs for the past 50 or so years.
Studio flash can be triggered using a sync cable between the camera and the power pack, or wirelessly via radio or IR (infrared) transmitters.
Some manufacturers have a short (about 1’) cable attached to the head, which is designed to be used with longer cables, which are supplied separately. This arrangement makes it easier to pack (or store) the heads more efficiently in tighter-fitting cases. The downside of two-piece head cables is that each time you add a connection point between the head and the pack you lose about a ¼-stop of light output, which in the case of two-part cables translates into a loss of a half stop of light output.
Tungsten Tungsten lights, also known as “hot lights," are high-intensity incandescent lamps (3200-3400K) that are available in a variety of configurations, including spotlights, floods, light banks and other variable and non-variable-angle lamp heads. Unlike flash heads, which illuminate the subject only at the moment of exposure, hot lights are continuous light sources, which make it easier to visualize the final effect of light on your subject. Studio flash offers lower-powered tungsten modeling lamps that only mimic the look of the subsequent flash exposure (and depending on the brand and reflector, some better than others). Tungsten lights allow you to previsualize with more certainty.
Some photographers prefer tungsten lights because they are smaller and easier to travel with than similar output electronic flash. Architectural photographers often prefer lighting with tungsten sources during evening hours because the color balance is close to the color balance of the incandescent lamps used in home lighting fixtures, though with the advent of fluorescent-based “eco” lighting, this is changing.
When using tungsten lights in room settings during daylight hours you must cover the windows with gel filters to compensate for the difference in the color temperatures of the outdoor 5500K to the indoor 3200K.
Tungsten lights are the number-one choice for copy work, due to their WYSIWYG qualities. They also put out great volumes of light for their price and size, are easy to work with and they travel well.
The down side of tungsten lights is that they produce heat… lots of heat, which makes tungsten less than desirable for portraiture. Another limitation of tungsten lighting is that with few exceptions, you cannot dim the light levels without affecting the color temperature of the light, which causes the light to go progressively warmer as it dims. As such, subjects lit with tungsten light require filtration to correct the light for daylight.
HMI HMI (hydrargyrum medium-arc iodide) lights, a standard in the motion-picture industry, are high intensity, continuous-output lights that unlike tungsten lights are daylight balanced, making them ideal for outdoor use. Also known as MSR (medium source rare-earth), GEMI (General Electric metal iodide), CID (compact indium discharge), CSI (compact source iodine), DAYMAX and Brite ARC, HMIs are much pricier than tungsten lights. Depending on the make and model, they often require frequent bulb replacement (every 300 or so hours of continuous use) in order to avoid what one manufacturer describes as “non-passive failure” (an industry term used to define the rupture of a pressurized lamp; newer HMI bulb designs have greatly expanded their life expectancy, but do take the time to read the fine print before choosing a system.)
Like tungsten lamps, HMIs can be used bareheaded, with reflectors, umbrellas, light banks and any number of reflectors and diffusers. In addition to video and motion-picture applications, HMIs can be used equally well for lighting stills.
LED Due to great advances in LED (light-emitting diode) technologies, LEDs are quickly finding their way into the studio. Dozens, if not hundreds, of daylight-balanced LEDs can be ganged together and configured in a variety of sizes and formats including ultra-flat, diffused light panels, spots and floods. LEDs are a continuous light source, which makes them easy to use when lighting your subject for video or still-image applications, but unlike tungsten lights, LEDs require little power and give off extremely low levels of heat. LEDs are available in numerous sizes and configurations, and many feature dimmers that maintain color balance throughout their range. Others allow you to warm or cool the color temperature of the light to fit the needs of the scene.
As a light source, LED technology is still in its infancy, and as such we can expect to see continued breakthroughs in LED output levels and new product introductions.
Fluorescent Daylight-balanced fluorescent lights have found their way into many studios in the form of flat, multi-tube light banks. Unlike electronic flash and tungsten light sources, which require deep enclosures, fluorescent fixtures require only a few inches of depth, making them ideal for lighting up broad areas in shallow workspaces. And they produce low volumes of heat.
The key limitation of fluorescent light banks is that despite the softness of the diffused, skin-flattering quality of light they produce, fluorescent lamps output relatively low levels of light for their size. Their length (and weight) also make them less likely to be carried to a location, as even the folding and roll-up models are more difficult to transport than smaller flash heads and packs.
Fluorescent lamps are also available in the form of conventional photo flood bulb/reflector configurations containing one or more individual lamps.
Which are preferable, electronic flash pack-and-head systems or self-contained monoblocks?
Electronic flash can be purchased as packs and separate heads, or as self-contained monolights that contain both a power source and the flash tube. Though there are pros and cons to both configurations, in the end both configurations accomplish the same basic goal.
As mentioned above, most power packs allow you to plug in two, three or four separate heads. Most heads come with cables ranging anywhere from 10- to 20-plus feet in length. With most packs and heads, you can control the flash and modeling light output of each head centrally from the pack’s control panel, and you can position each of the heads as you wish according to the length of the cable. For studio still life, this is a fine arrangement, but when shooting interiors or larger studio sets, without the use of extension cables (or a second set of lights for illuminating the background) you can easily find yourself limited by the working range of flash heads tethered by shorter cables.
Self-contained monolights have their own power supply and control panels, allowing you to expand your lighting range when shooting on larger sets or interiors by allowing you to decentralize your light placement to best fit your needs.
Another advantage of shooting with individual monolight flash is that if the power supply on one monolight fails, you can continue shooting using the other monolights, whereas if you are shooting with a pack and four heads and the pack fails, the show is over.
What sort of accessories should I consider to go along with my studio lighting system?
Light stands and booms Some lighting kits include light stands and some don’t. If you have to purchase stands separately, make sure the stands you choose will support the weight of the lamp heads and any light-shaping accessories you plan on attaching to them. Booms are also handy for floating your light source over or around your subject without having to shoot around light stands. However, if you do purchase a boom to go along with your lighting system, you should consider getting a heavier-duty light stand to go along with it, and an appropriate counterweight.
Wireless transmitters When working in a studio environment, the fewer cables there are to trip over, the better. Safety issues aside, wireless transmitters enable you to roam more freely when shooting handheld, as well as place your lights at greater distances from the camera position when using electronic flash. Depending on the make and model of your choice of wireless transmitter and lighting system, many wireless transmitters allow you to remotely test-fire your lights, adjust output settings and even orchestrate complex sequential flash patterns.
Light-shaping tools To go along with your lighting system, you’re going to need an assortment of reflectors, umbrellas, light banks/softbox, Fresnels and snoots to light your subjects. As for which are best for your needs, that all depends on what you’re lighting and how you want it to look.
Flash meter Your camera's built-in meter cannot read flash exposures, and while you can ball-park your exposure by checking your camera’s LCD, a flash meter enables you to take exposure readings down to 1/10-stop accuracy, which in the case of portraiture and studio still life is imperative. It’s worth noting that flash meters can also measure ambient light with equal levels of accuracy.
- Studio lighting systems are available in a variety of categories including electronic flash, tungsten, fluorescent, LED and HMI. The number of variables including subject matter, set size, fast-moving subjects and portability all go into determining the best system for your needs.
- In general, electronic flash is the best all-around lighting category in terms of output and flexibility for most professional applications. (None of them are perfect for every application).
- Electronic flash systems are available as separate packs and heads or as self-contained monoblocks.
- For continuous light output, tungsten lights offer the best bang for the buck, but they are hot and not balanced for daylight.
- HMIs are also continuous light sources, and are daylight balanced. They’re also much pricier than tungsten lights, and depending on the make and model, have a tendency to “non-passively fail” if used beyond “x” number of hours.
- After years of less-than-awesome offerings, LED lighting systems are rapidly coming into their own in the form of daylight-balanced, heatless, highly energy-efficient light sources. They are available in a number of configurations. Though LED output is still relatively low compared to electronic flash, tungsten and HMI lighting, we can expect to see great improvements in the not-too-distant future.
- Fluorescent lighting systems are also daylight balanced, but aside from producing lovely soft light for portraits, do not output great volumes of light for their size and weight and are not travel friendly.
- The light stands you choose to go along with your lighting system (assuming they are not included with the lighting system you choose to purchase) should be sturdy enough to handle the weight of your lights.
- Select light-shaping tools, i.e., reflectors, beauty dishes, umbrellas, softboxes, etc., that will produce the best lighting effects for the subjects you plan on photographing.