Basic Terms/Issues for Lighting
Ceiling Height: The height of a store’s ceiling is one of the most important factors that goes into a plan for lighting a jewelry store in such a way that the merchandise looks spectacular. As the source of light moves farther away from the merchandise, the power and intensity of the light diminishes. Stores with higher ceilings (over 9’) face some challenges with lighting. Stores with ceilings that are higher either have to use more lights that are spaced closer together to illuminate a showcase, or bring the light source closer by dropping down a track or using a pendant.
Color: The color of light is measured in Kelvin (temperature). The higher the temperature (Kelvin) reading the cooler the color of light and the lower the temperature the warmer the color. For example a light that is 3000K would be a warmer color and a light that is 5000K would be a cooler light. As the temperature of light gets too high (over 5000K) the color of the light begins to take on a light blue quality. Lights that are in the 5500K to 6500K will look “bluer” to the eye.
Bulb Life/Quality: Since LEDs are the “buzz” in jewelry lighting, care has to be taken when someone tries to sell you an LED claiming it will last for 50,000 hours. In the retail world that works out to about 12 years of use!! The more important criteria to look for in an LED is the warranty and the company offering the warranty. Lower quality LEDs are typically warranted for 1-2 years. The better LEDs are typically warranted for 3 years and the finest LEDs are typically warranted for 5 years. Be careful of warranties that are longer than 5 years, especially if the company offering that warranty is simply an online store without a track record/history of service to the jewelry industry. High wattage LEDs (over 21W) have a tendency to run hotter than they should in order to maintain longevity and should be carefully scrutinized.
Power of Light: The power of a bulb is measured in lumens. The amount of light that is generated is measured in Lux or, more commonly, in foot-candles (“fc”). Normally, the higher the lumens the higher the amount of foot-candles that will be generated by the bulb, except in the case of an LED. LEDs can have lower lumen output but produce more light (higher footcandles) if they use an advanced optic that provides for more light output. With LEDs, wattage and lumens do not always translate into a more powerful light.
(1) Most designers who understand the proper way to light a jewelry store will tell you that you light “for diamonds” and the rest of your merchandise will survive and do just fine. However, if you light for gold your diamonds will die. Diamonds require a bright white light that provide enough power to make them sparkle. Diamonds should be shown under lights that are 4000 Kelvin and higher. This provides a beautiful white color that stops short of taking on blue color qualities that come with lights that are over 5000K. Gold and warmer colored stones look the best under warmer colored lights 3000K to 3500K. However, if a store is going to use a single color of light throughout its showcases then the adage of “light with your diamonds in mind” is the best way to proceed.
(2) Make certain that your lighting is powerful enough to produce a minimum of 200 foot candles. Having light that is less than 200 foot candles is universally agreed to be lower than the minimum amount of light to properly light jewelry, especially diamonds. Readings of between 200 and 400 foot candles is the optimum amount of light power over a showcase depending on the store owner’s personal preference as to the amount of light that they think looks best.
(3) Have your ambient or general lighting be warmer and less powerful than the lighting over the showcases. The human eye is attracted to brighter light. If the general lighting in a store is the same color and power as that over the showcases then there will be nothing to attract the customers to the showcases and the store will have a cold non-inviting feel to it. By having the general (ambient) lighting less powerful and of a warmer color (between 2700 and 3500K) the lighting over the merchandise will stand out and attract the customer to the cases.
(4) When lighting a window display that has natural sunlight shining into it use twice the amount of light that would be commonly used over a showcase in order to combat the power of the sun.
Inside of Showcase Lighting: Having lighting inside of a showcase can really add sparkle and glitter to your jewelry. The best lighting for inside a case is LED. Be careful though when choosing the LED to make sure that the color and power of the lights work with the lighting above the case. You do not want your customers to be attracted to how your jewelry and diamonds looks inside only to have it look different on top of the glass where the sale is actually closed. Your customers may think that you are trying to trick them through the use of fancy lighting.