Lighting calculations and metrics for art and museum lighting are crucial for preserving and displaying artworks. In this article, you will learn how to balance color rendering and color temperature, two important aspects of lighting quality, for different types of art and museum spaces.
Color rendering is the ability of a light source to reveal the colors of an object accurately, compared to a reference source. Color temperature is the perceived warmth or coolness of a light source, measured in kelvins (K). Both color rendering and color temperature affect how we perceive the colors and mood of an artwork.
First and foremost the one thing we must take into consideration is how we as human beings see. Radiation comprised of variable wavelengths radiates from a source until it collides with an object causing one of two outcomes for each individual wavelength either it is absorbed or redirected. What is absorbed is not seen. We only see what is redirected to transfix our pupils. So we see not what it is but rather what this object is not. However, between what is and what is not we conceive highlights and shadows, contrast and depth, clues that give us some notion of truth about this subject. So we must ask ourselves what is important for one to see and not see in order to truly hear and understand the story being deciphered with ones eyes?
One way to measure color rendering is by using the color rendering index (CRI), which ranges from 0 to 100. A higher CRI means a better color fidelity, while a lower CRI means a poorer color fidelity. The CRI is based on how well a light source renders eight standard colors, plus six additional colors for some sources.
Another way to measure color rendering is by using the color quality scale (CQS), which also ranges from 0 to 100. The CQS is based on how well a light source renders 15 saturated colors, which are more representative of real-world colors than the CRI colors. The CQS also considers other factors, such as chromatic discrimination and gamut area.
For art and museum lighting, a high CRI and CQS are desirable, as they ensure that the artworks are displayed in their true colors. However, a high CRI and CQS do not guarantee a good color balance, as they do not account for the color temperature of the light source. For example, a warm white light source may have a high CRI and CQS, but it may distort the colors of a cool-toned artwork.
The color temperature of a light source can affect the mood and atmosphere of an art or museum space. A warm white light source (2700K to 3000K) can create a cozy and intimate ambiance, while a cool white light source (4000K to 5000K) can create a bright and crisp ambiance. A daylight white light source (5000K to 6500K) can mimic the natural light and enhance the colors of an artwork.
When it comes to balancing color rendering and color temperature for art and museum lighting, there is no one-size-fits-all solution. However, some general guidelines should be taken into account. It is recommended to use a light source with a CRI and CQS of at least 90 for high-quality color rendering. Additionally, the color temperature of the light source should match or complement the dominant colors of the artwork, as well as suit the function and mood of the space. Furthermore, it is important to use a light source with a color temperature that meets the standards and regulations of the art and museum industry. For example, daylight white light sources are often used for conservation and restoration purposes.