Light It, and Like It! (Part 3)

Another concern when installing art illumination is the angle created between the source of light, the art's surface, and the observer. For the most part, you don't want the angle such that the light will specularly reflect from the art's major surface directly to the viewer. A specular reflection is that glaring, shiny reflection you can get from a varnished oil painting, or glossy photograph, when it is illuminated from certain angles. This is like the reflection you get from sunlight glancing off the surface of water at a certain angle. Bright specular reflections like this will significanlty destroy the contrast of tonal gradations in a painting or photograph, resulting in washed-out colors and details.

Lighting Angle That Avoids Glare

Lighting Angle That Creates Glare

Alternatively, the avoidance of all specular reflections is not simply a hard and fast rule. It is possible that you may want to actually enhance and utilize some specular reflections, for instance, in highlighting the texture of interesting brushwork or palette knife impasto techniques. Here, specular reflections may be your friend instead of your enemy. The important thing is to make sure that the angle of illumination you use enhances the work rather than degrading it. Before simply guessing, you should always temporarily try the lighting in various angular relationships with the art before you permanently install it. When you find that "sweet spot" for the light that best shows the work, install it there.

Oil painting illuminated straight-on, 
little texture is evident, art appears flat
(SUNFLOWERS, © Nancy Bower, all rights reserved)

Oil painting illuminated with glancing light, 
brushwork texture is obvious and three dimensional
(SUNFLOWERS, © Nancy Bower, all rights reserved)

There is much more that could be said about the proper illumination of art, but this should be enough to whet your appetite and try it out for yourself. It is actually difficult to put "too much" light on an art object. Almost always (although there are exceptions) more light is better. Generally, you will find that the more light you put on the subject, the brighter and truer the colors appear, the easier fine details can be seen, and the greater the contrast range will be. About the only time that there can be too much light is when the light is either sunlight or fluorescent light– each of these should be absolutely avoided as they contain significant amounts of damaging ultraviolet light.

All of these effects having to do with more light being better are due to the idiosyncracies of the human vision system. More light is important for the appreciation of fine detail, since these features are mostly detected by the cone cells of human vision in the central high-resolution spot of the retina (the fovea). Since these cells are not very responsive to dim light, details can be lost when light brightness is low.

Also, the human perception of color is entirely dependent on these same cone cells, making it imperative that enough light is present to make color perception robust. Finally, although the dynamic contrast ratio of the human vision system is incredibly large (up to as much as a million to one), the static contrast ratio is fairly small (only about 100:1). This static contrast ratio has to do with how much of a tonal range can be perceived in a single illuminated view, as is the case of viewing a single work of art at a single time.  The greater the illumination, the more of the art's original tonal range can be appreciated.

Please, take the time, and make the modest investment required, to best illuminate the art that you so love. You appreciated it enough to spend a considerable amount of time finding it, and you spent a considerable amount of money to buy it. And the artist didn't spend their own emotional energy and creative capital so that you would hide it in some dim corner of your home or business.

Light it, and like it!