As photographers this is important to understand.  The subject we record with our camera, be it a person, a manmade object, or some element of the natural environment, is not the actual "subject matter" that the photographic process will record; it records the light or radiant energy which is directed through the lens onto the piece of photo-sensitive film.  As a photographer, we must learn to see light.  We must learn to respond to light.  We must learn to feel light.

This may seem simple enough, but perhaps it is more sophisticated, if not more complex than we might first think.  The minds of the most brilliant physicists in the world cannot completely comprehend all of the qualities and attributes of this electromagnetic radiation known as light.  Photographic books and articles seldom address our relationship with light in a truly useful way as it applies to photography.

Factual, scientific information about light is indeed important information, but not directly applicable to the medium of photography.  To become successful in writing with light we need to think differently.  Edward Weston had a simplistic, though insightful idea that might apply here:

"One must learn to look through one's eyes, not just with them."

The physiological process of looking is distinctly different than seeing photographically.  To see photographically, we must be aware of what the final image will look like - how shapes and spaces are altered when recorded in the rectangle or square often used in photography, and how the final image appears when presented in a two-dimensional medium.  We must also be attuned to the light.  Those working in color photography need to be sensitive not only to light and its different qualities, but to the physical and emotional qualities of various colors as well.  Those working in black and white photography may need to develop an even keener awareness of different qualities of light - sometimes elusive and evasive qualities of light.  A shade of gray can seem dull and lifeless, or it can transcend to an almost metallic quality in the photographic image.  Practice is needed to develop an ability to see light as photographic materials will render it.  There are many methods for developing this ability.  Trial and error is probably the most common.

One tool I find helpful, is Ansel Adam's Zone System of exposure and development.  Though most widely known for its use with black and white materials, understanding its concepts of what a light meter and film can do are applicable to color as well.  The idea of beginning to look at a scene in terms of reflectance of the various values, in terms of qualities of light and how they will translate in the final image is important in terms of learning to see light.

If we can accept that the medium of photography is one in which communication can take place, and if we can accept that photographers are writers with light, or communicators with light to expand this idea slightly, then it should be obvious that we need some tools available to us, tools with which we are at least competent, if not masterful.  If we think of photography as a language, then perhaps we need to look at the technical craft involved in the production of photographs as being analogous to the grammar or vocabulary of this language.

There are some involved in education in the medium of photography who contend technique and craft are irrelevant and have little to do with the content of a photograph.  To a certain extent this true.  However, in communicating with words we need to know how to structure our sentences, how to use the proper grammar and syntax to communicate effectively with the reader or listener of our statements.  We might have a great story contained within our mind, but if we do not have the ability to communicate those words effectively so that they are understood by other people that story remains for us alone.  Similarly, as photographers, we may make images primarily for ourselves, motivated from within our souls, hearts or minds, but I've never met a photographer who, given the occasion, wouldn't love to show his images to others.

It is imperative for a photographer to have a good grasp of the technical craft involved in this process in order to be free to effectively communicate with light.  This technique applies not only to focus, camera position, lens selection, and exposure, but also to developing a sensitivity to light.  Looking at a scene and realizing that the ultimate subject is light, we need to observe both how the light is revealing and how the light is obscuring.  Is it directional light?  Would it be different or more satisfying in soft light?