The Importance of Daylight Lamps

by Barbara van Look, Exclusively for Fire Mountain Gems®

Famous artists such as Vermeer, Renoir and Raphael knew instinctively what science has spent years researching: the human eye adapts to its background and can see relative color regardless of lighting. The eye has problems, however, with seeing true color as the light changes. In addition, poor light can add to eye strain, overly harsh lighting can create painful glare and accurate color-matching is difficult without daylight.

For the busy designer-artist, beading and jewelry-making often needs to be fit into whatever spare time is available, even if that means late at night after the sun has gone down. Most designer-artists will spend money to have the best supplies, then cheat themselves of the lighting they need to use those supplies accurately and beautifully.

Investing in proper lighting daylight lamps--such as Daylight™ lamps--allows the materials to show their true colors: your customers will be able to tell the difference. Here's why.

The Complex Nature of Light

Natural daylight from the sun contains all colors and wavelengths of light, from the visible light we can see to the infrared and ultraviolet we cannot. Each wavelength of light within the visible spectrum also has a temperature and adjusting the color temperature changes the light itself.

Different colors and intensities of light affect the eye's ability to stay on task. Avoiding glare means avoiding damage to the powerful, yet delicate, retina. Using sufficient light means preventing squinting, as well as the eye strain and headache that can accompany it. Full spectrum lighting is also used to treat forms of seasonal affect disorder (or SAD), which can seriously affect a jewelry maker's creativity and ability to work.

This has created demand for artificial lighting that can stand in for absent sunlight, giving the artist's eye the full spectrum of light it needs to create. Proper neutral lighting--such as light from a daylight lamp--offers greater accuracy when using color.

Color Temperature and Its Effects on Light

Color temperatures are measured in degrees Kelvin (K). Lower color temperatures (3,000K-4,000K) create reddish, ''warm'' light; this is often called Warm White. Higher color temperatures (5,000K-6,000K) create bluish, ''cool'' light; this is usually termed Cool White. With natural sunlight, these color temperatures vary with the weather and the time of day. Color temperatures are lower at dawn and dusk, creating the red and orange glow of sunrise and sunset. Color temperatures rise to a peak of approximately 5,500K around midday. At 10,000K, the color temperature is sky blue.

The human eye compensates for these changes in color temperature naturally and does not notice the subtle shift over the course of a day. We still see white as white, even though it is actually a pale orange in the light of the setting sun.

Artificial light sources create light with a variety of color temperatures. Those forms of artificial light can skew and distort color in ways that the eye cannot compensate for, leading to color choices under artificial light that become unattractive when brought under a daylight spectrum lamp or out into the true light of day.

Color and Artificial Lighting

Artificial light sources are measured for their ability to reproduce the effects of natural sunlight on color. This includes two major factors: the Color Rendering Index (CRI) and the Light Color Temperature (LCT).

The CRI of a light source is rated on a scale of 1-100. Higher CRI numbers indicate the light is closer to the effects of natural sunlight. This rating is based on the closeness to the ideal 100 rating: a bulb with a 96 CRI is twice as good as a bulb with a 92 CRI--not merely 4% better. The LCT of a light source refers to the color temperature in degrees Kelvin.

Ordinary incandescent bulbs have a high CRI number, however, the LCT is low (around 2,700K), and the light generated has a strong red to yellow cast. Ordinary fluorescent lighting distorts colors by shortening certain wavelengths of light, leaving odd spikes in the spectrum that might otherwise appear consistent to the eye.

As traditional incandescent and fluorescent bulbs heat up, the LCT increases, altering the quality of light and color. This is less prevalent with many of the new full spectrum light sources. Most full spectrum lighting is designed to emit light with an LCT of 5,200K to 5,300K, typical of midmorning sunlight on a bright, clear day. These daylight lamp bulbs are available in a range of shapes and styles; the shapes do not affect the light generated by them.

A CRI of 80 or higher offers balanced lighting critical to creating art. The closer artificial light sources come to natural sunlight, the better color choices artists can make and the less eye strain they will suffer to achieve it. Which means artists can match colors accurately, regardless of the time of day.

How to Evaluate Full Spectrum Indoor Light Sources

Most full spectrum lighting equipment includes the CRI rating. With 100 being that ideal northern midmorning sunlight so loved by painters, bulbs are rated according to how close the light they produce gets to that number.

The higher CRI number, the more accurate and even display of color you will see. High quality full-spectrum bulbs available in standard stores today usually have an 85 CRI, while specialized fluorescents can be rated as high as 91. Lighting equipment without a listed CRI probably measures 80 or lower.

An 85-90 CRI is acceptable for general use, though they give colors a slight green cast. For task lighting or color matching, it's ideal to seek bulbs with a CRI at 95 or higher.

Using Proper Lighting for Better Jewelry-Making

Make jewelry-making and beading easier on your eyes with selective changes in your craft room lighting:

  • Invest in proper craft lighting such as Daylight™.
    • Don't lose time and energy due to pain or discomfort, and don't cheat the materials of their proper colors.
  • Choose neutral white lighting using light sources with high CRI listings.
    • The higher CRI listing, the more accurately it will display color.
  • Reduce eye strain (and headaches) by using enough lighting to properly see your project.
    • If you need to squint or peer to see your work, consider more light or a magnifier--or both.
  • Choose low-glare light sources, especially when working with highly reflective surfaces.
    • Like a lighthouse on the ocean or sunlight on the snow, too much light can affect the eye, or even cause damage.
  • Move lighting sources according to material being used or project needs.
    • Lamps with adjustable features, such as a swivel or gooseneck stand, help prevent glare and direct lighting to where it is most needed.
Shop ... Additional Resources ...