The "Character" of Light

This is the third in a series of posts about light.  The first was on June 4th and titled "To Flash or Not to Flash" and the second was on June 17 and titled "Light and Earthquakes".  If you are just learning about light in photography you should start with the June 4 post.

What does "character" mean when we talk about light in photography?  Lets start by defining a few terms - "hard light" and "soft light".

Hard light occurs when light beams are traveling in a very straight line.  The most universal example is direct sunlight on a clear, cloudless day.  On a day like this, look at your shadow.  It will be very sharply defined with clearly defined edges.  The areas outside the shadow will be very bright and the areas inside the shadow will appear abruptly dark.  This is the classic example of "hard" light.  On-camera flash can also create this type of hard light

Generally, hard light is created when the light source is small and intense and far from the object it shines on.  We generally do not think of the sun as small but it actually is a small point light source.  This type of light often creates scenes that are beyond the cameras ability to record intensities of light.  The result is either highlights with no detail, shadowed areas with no detail or both.

Here is an example of a water lily shot in direct sunlight:

Notice how distinct the shadowed areas below the flower pedals are.  Those areas and the water are black without detail.  To me, the flower was the most important part of the image so I exposed to capture detail in the flower and let the shadowed areas go to black without detail.

In hard lighting situations you will frequently need to make exposure decisions like this.  Understanding these situations and taking control of them will result in much better images in this type of light.

Soft light occurs when light is diffused and travels to the subject from many directions.  The classic example of this is an overcast day.  Sunlight passes through a layer of clouds that cause the light to spread out.  Instead of coming from one spot in the sky, it comes from the entire sky from all directions.  On a day like this look at your shadow.  If there is a shadow it will be faint and there will be a soft transition from bright area to dark area.

On days like this your camera can usually handle the full range of light intensities in a scene.  When using flash, you can create softer light by diffusing the light from the flash.  You can do this by bouncing the light off a ceiling or by passing the light through some type of diffusion device that spreads the light.  Many flash units come with a plastic diffuser and a wide variety of units are sold as options.

I hesitate to describe one type of light as "better" to work in than another.  Understanding the character of the light you are working in will help you make better images by making better exposure decisions.  I personally prefer softer light for my work in nature photography and for portrait photography.

This flower was shot in very soft light.  There are no shadows and the camera easily handled the full range of light intensities in the image.

One disadvantage to light that is this soft is that there are no shadows.  Shadows can be a great compositional tool and they can add depth to an image or highlight shape or form.

Again, I don't think there is a right or wrong light.  There is only understanding the light and learning to take advantage of its characteristics.

The third "character" of light that I want to discuss is color.  In general, the color of light from the sun is affected by the angle that the light strikes our atmosphere and by dust, moisture, or pollution in the atmosphere.  The color of light can also be affected by altitude. 

Expect light to have a shift toward red and yellow early in the morning and late in the evening, sunrise and sunset.  When the angle of light is low, the light passes through more atmosphere and some of the blue is filtered out.  That is how we get the great sunrise and sunset colors.

Expect light to have a shift toward blue on overcast days, in shadowed areas on a sunny day, and at higher altitude. 

In film days you purchased film that was rated for color temperature.  By matching film rating to the light you would create images that had correct color balance.  With today's digital cameras you have the option of changing the color balance for every image if you want to.  This can be a very powerful creative tool that replaces the bag of filters that many photographers used in the past.

I like to think of myself as an honest and truthful person but I frequently lie to my camera.  How to make great images by lying to your camera about color temperature will be the subject of a future post.

I hope this series of three posts helped lay a foundation of understanding about how light works.  In the weeks to come I will try to build on the three ideas with information on how to make light work for you in your photography.