HIDS

When Thomas Alva Edison invented the first viable incandescent light bulb in 1878, he used a simple strip of paper between two wires in a vacuum-sealed glass bulb.

That basic concept--sending current through a filament (now most often made of tungsten) in a vacuum-sealed bulb--is still the foundation of modern light bulbs. But the technology has gone far beyond Edison's prototype to produce modern bulbs in an array of brightness, clarity, temperature and range. This offers framing retailers, for whom a store's lighting can be as important as its location, a nearly endless selection from which to choose.

In part one of this two-part series, which ran last month, we covered the basics of lighting design and the use of track and recessed lighting to illuminate displays and individual retail spaces to best effect. Here, in part two, we cover the basics of lighting technology--including light bulb types, characteristics and terminology so you'll know what to look for when you weigh your lighting options.

Basic Terminology

The terminology of lighting can seem to be an alphanumerical soup to the uninitiated. However, there are a few basic bulb characteristics that can help clear the confusion as you head to your local or online lighting supplier:

Brightness Although some might believe a measure of a light bulb's brightness is its wattage, watts are actually a measure of power consumption: The lower the wattage, the less power a bulb consumes. To gauge a bulb's brightness, however, look to the lumens rating on the packaging. A dinner candle, for example, generates about 12 lumens, while a 60-watt soft white incandescent bulb glows at around 840 lumens.

Color rendering To make sure you are choosing a true-to-color bulb of any type, check its specifications. In lighting parlance, the "color rendering index" (CRI) is the number to watch. The CRI is a measurement that rates light sources from 0 to 100. The top rating, 100, represents the sought-after quality of natural light; as the rating decreases, so does the quality of color representation. In short, the higher the CRI, the better the light.

Color temperature Measured in Kelvin, color temperature refers not to degrees, but to the color quality of the light a bulb produces. "Warm" bulbs have a color temperature of 3,000 Kelvin or below and can cast a yellowish glow. "Cool" bulbs, on the other hand, have a color temperature of 3500K or above and cast a whiter, clearer light, explained Kathy Abernathy, IALD, of Abernathy Lighting Design in North Providence, R.I.

Beam spread Beam spread refers to the angle of light a bulb projects. Retail spaces, especially art and framing gallery environments, often use bulbs with a variety of beam spreads to achieve different lighting effects. Light bulb suppliers generally provide the angle of the spread on their specifications--bulbs with a spread of 25 degrees or greater are generally considered a flood, while bulbs with a spread of less than 25 degrees are considered spots.

Bulbs with wide beam spreads offer a softer light than those with narrow spreads, explained Mark Scott of USA Light & Electric. "The wider the coverage, the less light the bulb projects because you are spreading the same amount of output over a larger area," explained Scott.

With an understanding of these terms in hand, a retailer can be more fully prepared to choose a good mix of bulbs for a retail space, providing narrow-beam, high-color rendering spots for a display or widebeam lighting for a wall-washed effect.

Lighting Options

Each type of light bulb offers a different effect and function for a retail space. Each also has its own list of pros and cons:

Incandescent Harkening back to Edison's invention, incandescent bulbs are the oldest and most common option available. Inexpensive, they offer a soft light that reflects true colors. However, it is the least energy-efficient of bulbs and can be more expensive to use in the long run.

Halogen Halogens use the same technology as incandescents. However, they produce a whiter, brighter light with truer color renderings than standard incandescents, and make better accent lights. Although halogens are more expensive and generate more heat than standard incandescents, they last up to three times longer. A common type of halogen is the MR-16, often used in gallery environments. However, MR-16s come in many different brands from many different manufacturers, so experiment to find the one that works best for you.

For instance, among MR-16 halogens, Scott recommends an upper end product such as the recently introduced SoLux bulb. The SoLux has a color temperature of 4,700K (rather than the 3,000K of most halogens) and a CRI of 99.35; it's available with a variety of beam spread angles, lasts for 3,000 hours of continuous use, and costs about $6 per bulb. "Halogens like the Solux offer museum-quality lighting," he said.

Fluorescent One of the coolest-burning and most energy-efficient of bulbs, fluorescents are experiencing a renaissance. Members of the newest generation of fluorescent bulbs project true-to-color light that is close to natural daylight, making fluorescents a viable option for general lighting in a gallery, frame design area or workroom. The newest options in fluorescents even make them a viable choice in areas where color-correct light is a must. However, unlike halogens, fluorescents cannot be dimmed or focused as an accent light and do not project well.

Metal halide The newest addition to retail lighting options, metal halide bulbs offer the best of all worlds: They are relatively cool burning, energy efficient and long-lived and offer a high color rendering. However, their price tag, at $50 and up per bulb, can be a deterrent. In addition, these bulbs are not dimmable and cannot be turned off and back on immediately (they must be allowed to cool for a few minutes).

If retailers are unsure of what type, size and wattage bulbs to buy or distrust the new fluorescent options, they can visit a light supplier's showroom to test drive the newest products, suggested Abernathy. "They'll be glad to turn on different light Fixtures for you."

No Fluorescent? Not So Fast

There has been one lighting rule that many art and framing retailers swear by: Ditch the fluorescents in the showroom. Although fluorescents are cool-burning and highly energy-efficient, they have a reputation for making artwork look downright dingy. As a result, they've lost ground to their more true-to-color halogen brethren.

However, fluorescents' bad reputation, when it comes to color, is changing. Lighting manufacturers have developed fluorescent options that provide the color-corrected light that art and framing retailers demand. The "big three" light bulb manufacturers--Philips, GE and Osram Sylvania--now offer fluorescent light bulbs that provide a more natural-looking, color corrected light, said Abernathy.

"Fluorescents now offer good color rendering and can be a good source to use because they're so energy efficient," she said. "All the bad color myths about them should now be working their way out."

Standard incandescents and halogens often rate at or near 100 CRI. Fluorescents of the past fell below 70 CRI, but today there are fluorescents that offer enhanced CRI ratings of 85 or more.

For example, Philips now offers its TL-90 fluorescent bulb, which has a CRI of 95 to 98; also available are its Colortone[R] 50 and Colortone 75 bulbs, which rate at 92 and 95 CRI and burn at 5,000K and 7,500K, respectively. GE's Starcoat[TM] line of fluorescents offers as high as 86 CRI, while Sylvania's Dulux line of fluorescents offer 82 CRI. These bulbs are more expensive than incandescents, but their increased efficiency and enhanced color rendering may justify the extra cost.

However, fluorescents still have limitations. They're not dimmable and they do not make good accent lights, Abernathy said. Halogens are still the light of choice where such effects are desired in a gallery area.

"But fluorescents are a good, cool, energy-efficient light source," she said. "The new high color rendering fluorescents are a good choice for a general light source that you turn on every day."

The New Metal Halides

The Cadillac of light bulbs is the new high intensity discharge (HID) bulb now available to the retail market. Up until now, the claim to fame of HID bulbs, otherwise known as metal halides, has been their ability to light large areas, such as parking lots and sports arenas. However, the orange and blue tinges they cast made them ill-suited for a gallery environment.

Now, there are new, smaller metal halide bulbs available, specifically designed for the retail and designer markets. With CRI ratings of 85 and higher, bulbs such as Philip's MasterColor[R] line, GE's ConstantColor[R] and Sylvania's Tru-Color[TM] Metalarc[R] family of metal halide lamps are viable options for the gallery and frame shop.

"HIDs use less energy than halogens," explained Alicia Kapheim, a lighting application designer with Philips Lighting. "They last a minimum of 10,000 hours, but some are rated longer, in the 10,000- to 12,000-hour range."

At $50 to $75 for the bulb (not to mention $100 or more for the fixture), they represent the most expensive lighting option. But they are also the most efficient, lasting up to 10,000 hours in constant use. That means a retailer whose shop is lit for 10 hours a day, six days a week won't have to buy a new bulb for nearly three years.

Lighting, Lighting, Lighting

The bulbs and fixtures in an art and framing environment should, ideally, serve both its form and function. Although aesthetics are important, said Barry Cohen, versatility can be equally so.

Track lighting is one of the most popular choices among art and framing retailers, he said, especially those who incorporate standard fixtures that can accommodate any type of screw-in light bulb. Standard track fixtures are an especially good choice for an art and framing gallery in which lighting needs can change from artwork to artwork. "Over the years, we've supplied 2,000 to 3,000 art and framing retailers, and about 70 percent of them use a universal track fixture" said Cohen.

But no matter what type of bulb a retailer chooses, quality bulbs and creative presentation are the foundation of good lighting design. As we discussed in part one of this series, cost should not be the only factor to consider when choosing bulbs and fixtures--bulb life and light quality should also come into play. And perhaps even more important, a retailer can avoid a fiat, sales-stifling display of framed artwork by experimenting with different lighting combinations.

"A good gallery will have a number of lamps and choose the one that best illuminates a selected object," Scott said."There is no one bulb for every application."

For many retailers it's all about "location, location, location" but it may be time to give lighting the triple-emphasis as well. With its undeniable effect on consumer mood, lighting makes a difference. With some knowledge of the basics and an inventive approach, a retailer can create focal points, stimulate interest and lead a consumer's eye through a store--boosting sales, brightening the atmosphere and best of all, encouraging first-time buyers to come back.

SOURCES

* Abernathy Lighting Design, (401) 233-4412

* Light Bulb Warehouse, 800-495-5554

* Phillips Lighting, 800-555-0050

* USA Light & Electric, 800-854-8794

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