It's the light Stupid!!!!

Nathan McCreery

“It is light that reveals a matter; the form and shape of an object. It is light that allows us to "peek" into the soul of our subject and to expose its essence.” Nathan McCreery 2004 from an address to the Imaging Professionals of the Southwest meeting in Albuquerque, New Mexico

There are five things that you need to know about light. I believe that if you know, and understand, these five things you can effectively photograph anything and make it look as good as it can look. These five things are; quantity, quality, direction, spread and color.

Quantity

Quantity; almost every one understands that sometimes there is a lot of light and other times there is less light. The quantity of light available to expose sensitized material, whether it is a silver halide emulsion or a charged coupled device (sensor in a digital camera) is measured by a light meter of some kind. An exposure meter simply measures the amount of light available to a scene and translates that amount of light to a series of numbers that tells you how to set your camera to get a “correct” exposure. You have to measure the amount of light incident to the scene to know how to set your camera’s exposure controls. I won’t spend a lot of time on this subject since most people can look at one situation and realize that there is either a lot of light available or not a lot of light available. The ability to understand that is, or should be, pretty intuitive.

Quality

Quality; here’s where a lot of people really have trouble understanding and seeing, and some never do grasp what we’re talking about. There are two qualities of light; spectral and diffuse.

Spectral light is characterized as being harsh with shadows that have sharply delineated edges. Spectral light sources are small in size, relative to the object being photographed. As such direct sunlight will be very specular in its quality. The smaller the light source is, the more specular its light will be.

Specular light is one of the most difficult light sources to work with because it is so harsh in its nature. As a general rule, the more specular the light source is, the more difficult it is to work with. Because of that characteristic I usually suggest that beginning photographers avoid using it whenever possible. It is interesting note that some of Ansel Adams most well known and iconic landscapes were created using a spectral light source so it isn’t that the light source can’t be used to create stunning photographs. It’s just that it can be difficult to use, and it requires visual sophistication and technical skill to make it work for you and not against you.

Diffuse light has the characteristic of emanating from a larger light source. The larger the light source, the more diffuse the light quality will be. Diffuse light has the characteristic of having soft edged shadows and of being a gentler light source, and also being relatively easy to work with and being very forgiving. Objects that are illuminated with a diffuse light source will have more open shadows.




Another factor in using Diffuse light is that it has lower overall image and local contrast than spectral light. In fact where spectral light can have a contrast range, or scene brightness range, that is almost un-manageable, a scene that is illuminated by diffuse light may be so low in contrast that the scene, as presented, is boring and in need of a boost in contrast.

There are two times each day when you are guaranteed the very soft luminescent light that photographers covet so much. One is just before sunrise while the illumination from the sun is reflecting back into the scene off the western sky. At this time of the day the moisture from the previous evening is still on vegetation and the light will be very soft and diffused. The other is after the sun has cleared the western horizon. Again, the quality of light will be very soft and luminescent with many of the same characteristics as pre-sunrise. One other benefit to photographing after the sun is down is that, many times, the color of the light will be noticeably warmer than at sunrise. I try to use both times of the day to make photographs when I am working.

The unpredictable factor that can create amazing light possibilities is cloud cover. When there is strong cloud cover, the clouds themselves become the light source rather than the sun. Essentially they become a giant diffuser or, in some cases, a reflector depending on their orientation to the sun and the scene. To summarize, diffuse light will occur outdoors when the sun is hidden by the curvature of the earth, both before sunrise and after sunset, when there is significant cloud cover, and when the direct light of the sun is blocked by a physical structure such as a hill, mountain or building. The bottom line here is that the photographer needs to be ready to deal with these qualities of light and know what to do when they present themselves. When you are out, even when you aren’t making photographs watch the light and learn to see what it is revealing to you.

Direction

One of the most important things to watch, and be aware of, is the direction of light. Watch the effect its direction is having on the thing you are interested in portraying. What is happening to the highlights and the shadows?

It is the direction of light that will give an object the illusion of being round in a photograph. Remember that a photograph is only two dimensional but we need to create the impression that our photograph has depth and dimension. If we don’t the photograph may appear flat and uninteresting.

The only tool we have at our disposal to do that is light direction. When the light source is at an angle to the scene or object we are portraying one side of the object will reflect more light back to the camera than the other side. It is this difference in quantities of light reflecting off the object to the viewer that will create the feeling of roundness and give depth and dimension to the scene. You also will find that not understanding what the direction of light does to scene can be deadly in the production of a finished photograph.

Usually, when the light is directly overhead, it is not very conducive to making great photographs. There can be a tendency to be so “taken” with an object or subject or scene that we respond emotionally to it. The camera only sees the scene analytically. It is incapable of an emotional response but the emotional response is what we want. Because of this we must learn to see things the way our camera sees them. .

Spread

Spread; when I speak about “Spread” I am talking about how many stops difference there are between the most brilliant highlight in the image and the deepest dark tone where you will want separation of tones. Usually, in your photographs you will want the highlights to carry detail, or tonal separation, and the dark areas to also carry detail, or a separation of tones. The times when you will want to have highlights with no detail or large areas of dark tonality without detail are relatively small. We almost always want the highlights and the dark tones to carry detail. Of course there are exceptions to this “guideline” but they are definitely the minority.

It is important for you to know your media and its exposure characteristics. You need to know which part of the image you meter is reading to give you exposure information. You need to know how many stops of light your media is capable of recording before you begin to have either highlights that are blown out, with no detail, or shadow areas that are blocked up with no detail. My understanding is that a digital camera set to record an image as a J-Peg file is only capable of recording about a 4 or five stop range of tones. If we set the camera to record the image in RAW it will increase that range some but there will still be many situations in which the range of tones in the scene will far outstrip the camera’s ability to record them.

When this type of situation arises, and it will, the photographer is faced with at least two possibilities. Record the image with the knowledge that you are going to lose either highlight detail, with the highlights completely “blown out”, or shadow areas that are so dark that they carry no detail. Neither option is desirable. The other possibility, or option, is to remember the spot and come back to it when conditions are such that the spread is within your camera or media’s limitations.

It is very important that the photographer pay close attention to spread, or scene brightness range, to get a digital file or negative that will closely mirror what the photographer had in mind when they made the original exposure. Don’t rely on the camera to save the day for you. You need to manage the creation of the original exposure so that it gives you the information you will need to create the photograph you see in your head.

Color

In the days before digital it was mandatory that a professional who photographed in color have an understanding of how the color of light would affect a photographic image.
For instance, the color of light emitted by a fluorescent light is markedly different that the color of light the proceeds from an incandescent light bulb. If you weren’t aware of the difference there would be a big, very unpleasant surprise when the film came back from the color lab. The same holds true for film that was exposed by an electronic flash, film that was exposed outdoors under sunlight and film exposed using a regular light bulb. Each light source had a different color temperature or color and each had different filtration requirements to get a pleasing, if not accurate, color balance in the finished work.

Of course, every digital photographer today understands that the white balance of the camera must be set on the correct calibration so that the file as it comes out of the camera is as accurate as possible. It is necessary that you make sure that the color settings on your camera match the color of light that is being emitted by the light source you are working with.

In Conclusion

If your desire is to create truly eloquent works of photographic art the road probably won’t be easy. There is a daunting learning curve. While it is true that modern photographic equipment has made the task easier than ever, it is also true that you’ll never be able to consistently produce work that is greater than your knowledge level. My strong suggestion to you is that you begin with all haste to become as knowledgeable about light as soon as you can. Only through understanding light, and a few other things, can you begin to create the masterpiece that is hiding within you. It’s the light we photograph, not the object.

This essay is owned exclusively by Nathan McCreery. It may not be reproduced by any means, in part or as a whole, without his express consent. It may be used in areas of scholarly research with the correct and appropriate citations. Copyright 2010, Nathan McCreery, Clovis, New Mexico.