By the Light of a Window by Gary Regester, 1983

Long before the first ancient took charred stick to wall, light was streaming through the openings of his dwelling — a natural, unpretentious illumination that has for centuries revealed the artist’s subject with an elemental and essential beauty unparalleled by the artificial lighting formulae of today.

Our ancient friend with charcoal in hand was probably not duly impressed that the light from his “window” revealed his drawing, family and friends in “elemental and essential beauty unparalleled”. Ever since our first Artist took to Shelter, that broad, even light from a window has been woven into the fiber of the Mind’s eye.

But because the human mind overrules its senses, it took artists a long time to see as light revealed. Not until the High Renaissance of the 16th century did artists begin to render, with palette and brush, the exact light that fell from their window onto their subjects. Then shadow became as important in revealing form as light. This new technique they called chiaroscuro from clarus obscurus (clear dark).

The painter thought “not of outline, but of three-dimensional bodies made visible, in varying degrees, by the incidence of light”— the play of light against dark, shadow against highlight, the edge of one form falling into darkness to be separated against the modeled highlight of its neighbor. Such artists as Titian, Raphael, Michelangelo, da Vinci, and Giorgione, followed during the next century by Caravagglo and Rembrandt, lifted painting from the prejudiced mind to the unbiased eye. Seeing Light as it revealed itself became all important.

The photographer is an extremely recent recorder of this continuum. With emulsion and lens, his machine is able to “see with a brutal objectivity surpassing the ability of his own mind. Seeing the Light as it reveals itself becomes even more important. Master lighting and the machine is no longer the master.

Window light A.D. (After Daguerre).

As early photographers followed their painterly forebears, (tungsten light would not be invented for another half century,) our studio forebears not only used but were dependent on simple window light. No doubt the relatively vast amount of light required by early emulsions made the pioneering photographer desire a more brilliant source than the window light that had satisfied the minds of the 16th century painters. With the coming of Mr. Edison’s light (1879), the photographer realized a new, relatively portable and, infinitely more variable tool which with faster emulsions opened Pandora’s door.

Through succeeding years, photographers devised various artificial lighting techniques and some of these complicated systems have become the “classic” lighting solutions of today. These complex ratios of multi-source light confuse not only the photographic artist, but his subject as well. It must be observed that the glory and the power of the modern electric light, and its recent offspring, the electronic strobe (Harold Edgerton, 1931), momentarily blinded the studio photographer to the beauty and simplicity of the original lighting source — the window light.

However, as perfect as window light is for almost every application, light from a Window, has, its very apparent limitations; the most obvious are in the areas of portability and variability.  In order to overcome these shortcomings, many photographers have successfully attempted to merge the versatility of modern technology with the beauty and simplicity of window light. These photographers, working primarily in the field of product illustration and advertising, have designed and constructed their own aluminum, fiber glass or foamcore “light-banks”. These “windows” of light are able to duplicate the effect of window light on the photographer’s subject matter and increase the degree of movement and uses for this quality of light within the studio.

Constructing your first $15 light bank.

Theory and history is one thing, actual experience another. There is no reason to accept another photographer’s opinion about window light, (particularly when he is peddling an expensive enough commercial light bank of his own design and manufacture,) when a light bank of your own design and manufacture can be made for all of $15.

You will need the following materials and tools: a sheet of foamcore, a roll of duct tape, a sheet of translucent diffusion material, one sharp matt knife, a pencil, a square and a straightedge.

Foamcore, a white paper/foam/paper laminate, can be found in any large art supply house. You will need at least a 40x60” sheet (about $6) to make a 24x32” light bank. Gaffer’s tape or less ex pensive duct tape can be found in cine supply houses, your camera shop or hard ware and larger drug store chains ($4). The sheet of diffusion material will become the front screen of your light bank. What you want to consider is the degree of translucence and the color of the material. The color should be as neutral as possible, though since most strobes flash at about 6000 degrees Kelvin and film is balanced at 5500 (Ektachrome users read 5000) if you err, err to the warm. There are many materials to suggest as possibilities: tracing paper in different weights; architect’s vellum of different weights; plastic shower curtain (Sears’ white pebbled one is excel lent); the ubiquitous bed sheet; and any number of diffusion materials to be found in a cine supplier’s shop or the artist’s supply.

Basically, you are going to design a box, which if it has six sides, five will be foamcore and the sixth will be a translucent screen. The strobe or strobes are usually, but not always, positioned opposite the translucent screen. This “box” can be deeper or shallower. The deeper you make it the more even the light will be across the front diffusion screen (inverse proportional law of light). Conversely, the shallower, the greater the difference between the center and corner light values of this front screen. The “box does not have to be a box. Consider a pyramidal or complex geodesic to enhance internal reflection and save weight and material.

Next, what will be the shape and proportion of your front screen. A square is an excellent shape for a first light bank as your side panels and rear panel shapes will be easier to determine. Circular light banks are a bit difficult for a first attempt. Do consider a rectangular front screen over a square as a rectangular light bank will give you considerable added versatility with your subjects and is not that much harder to design. Plan too for the future, choose a shape and size now that will work well with the next bank you build.  For instance, two 24x32” banks built today and a 32x48” bank built tomorrow, joined ed to edge would form a combined screen dimension of 48x64” or a long 32x96”

Your curiosity and imagination are your only limits. For some photographers every light bank must have a silver lining. Try it. See if the expected increase in light efficiency is enough to offset any changes in light quality and color temperature.

Experiment with adding a deflector in front of the strobe. If you could lower the screen’s center brightness, while raising the side and corner values, you could create a shallower bank with a front screen evenness of a deeper light bank. The deflector can be a piece of shower glass, a silver metal or mylar cone, a backpacker’s cup or any of many materials. Take a rod the same diameter as an umbrella post and affix your deflector to one end. Then using- the umbrella hole on your strobe or stand adapter, position the deflector in front of the flash tube and adjust until it works best. Or make the strobe itself become its own deflector by placing the strobe inside of the light bank and aiming it into the rear of the bank. See if you prefer a front screen with a slightly hotter center value or slightly dimmer. Or perhaps you find total evenness best of your subject.

As you continue to consider your light bank design, (and do design with paper and pencil before you start cutting up foamcore; in fact, get ideas from as many other photographers as you can before you wield your knife, take into account the weight of your light bank and how you intend to support this window of light and still retain the necessary amount of movement and articulation required by your subject matter. A 24x32” foamcore tight bank weighs about 3 lbs., not including the weight of the strobe(s). Also consider how you will ventilate your light bank to prevent over heating. Convection works well, but do the cooling ports you cut in your bank spilt unwanted light. Make sure your strobes, if they have modeling lamps, have internal cooling fans. Fans increase the life of both strobe tube and modeling lamp; use them.

Finally, with drawings, calculations, tools and material at hand, cut and tape. If you need a collapsible, light bank for travel reasons, duct tape the edges of the foamcore panels with the full width of tape. This will allow you to put the bank together on location with a second layer of tape and then remove it after the shoot without damaging the panels.

Light banks vs. umbrellas.

Both umbrellas and light banks diffuse a direct source of light such as a strobe into a broad directional light source. The modeling of form from such a source is well within the contrast range, of most films and quite beautiful. Umbrellas are lightweight, portable, relatively inexpensive -and very quick to assemble. For these reasons, umbrellas have been widely used as light diffusers for the last twenty years.

Disadvantages of umbrellas are the obstructed highlight that results, the umbrella post, and the characteristic “focused” quality of light. The obstructed highlight is, of course, a serious problem to product photography less a problem to portraiture and other illustrative work. The umbrella post forces the umbrella’s reflective surface, in many cases, to be too far removed from the subject, plus the post always seems to find its way into the photograph.  These first two disadvantages can be somewhat overcome by translucent umbrellas reversed, that is, the light from the strobe passing through the umbrella. But then light spill, flare and light efficiency become a problem.

The third disadvantage mentioned, the characteristic “focused” quality of umbrella light, can also be an advantage. Umbrellas are a portion of a sphere. Correctly positioned, light from a strobe will be reflected out of an umbrella in a focused column. Thus the light from an umbrella does not behave as natural window light, nor does it follow the inverse proportional law of light. If you need to get better light efficiency far from the light source, use umbrellas. If you want to mimic the falloff characterized by window light use a light bank. Light banks, too, have had their disadvantages. These “light-monsters” tended to be expensive, cumbersome, sometimes makeshift and be cause of their size and weight limited to studio applications.

Lighting and light banks.

The first and last law of lighting is “if it looks good, shoot it!” Don’t let other people’s ideas and formulas get in your way. These formulas ‘are good as guides and instruction, but should not be mistaken for an end in themselves. By the time you have copied the “Master’s” lighting technique, that “master” is that much farther down the road, leaving his throng of devotees far behind. Learn to see light with your own eyes and the “masters” are destroyed.

Teachers of lighting consider or should consider light banks an anathema (an accursed thing). The “cheater” light from light banks is too easy and teaches one little or nothing about why it is so beautiful. Better to start with hard light sources, spotlights and diffusion cards to learn lighting. Begin- fling students should hide their light banks far from instructor’s eyes, bringing them out only for their “own” work.

A light bank -dimensional pane of  light and cannot be “focused’ as can the beam of light from an umbrella. Thus the closer to your subject, the better.  Since this plane of illumination has no obstructions, it can be brought very close to the object. The most beautiful “wrap” or modeling of the light occurs if the lightbank’s front screen is at least as large as the subject. Situations and. circumstances do not always allow for this “best case”, let your eye be your guide.

The broad surface of a light bank makes it perfect for “single-source” lighting. Remember contrast or lack of it is the relation of tight axis to camera axis. Bring the harshest light down over or around the lens, and the lighting will be extremely flat, as with a ring-light. Move that source away from the lens and you create contrast. You need to show form, light and dark, shadow and highlight. But a hard light source creates hard contrast, which because of taste and emulsions, will require fill, if that fill is a second light source, then you have to watch for its shadows and highlights. And on and on, for every light you add.

Consider a single broad source. Such as a light bank. Place one edge of the broad source near the lens, while the remaining surface creates your modeling in the subject. The soft contrast you create is as beautiful to your eye as it is to your emulsion. You no longer need your “key and fill” formulas, and you no longer have the con fusion that results from multi-source lighting.

If your subject matter needs additional fill, fill with white or dull silver reflective cards or screens. Reflective surfaces work well with any light source because they usually add fill but not confusion.

And in conclusion.

“lf it looks good, shoot it.”

close this window