As a guy who is known for his work with flash and strobes, many think that I’m not interested in shooting natural light. This could not be farther from the truth. I’m a keen observer of daylight, its many colors and shapes, and the way it changes rhythmically throughout each day.
Daylight often provides the ambient light in my shots. Since I can typically do little about ambient light — other than make it appear brighter or dimmer by my choice of shutter speed — it is important to have a sense of how daylight changes throughout the day so that I can choose my shooting time accordingly.
The following is excerpted from Chapter 3: Using the Light Around You of my upcoming book Light and Lighting (to be published in the fall by Peachpit Press, details here).
The Daily Cycle of Sunlight
As a photographer, have you ever considered how sunlight changes through the day? I’m sure you know that the direction and intensity of sunlight change. Can you also describe how the color, contrast, and hardness of sunlight change? For instance, how is early morning sunlight different than sunlight at high noon? Or what is sunlight like a half hour after the sun drops below the horizon?
As shown in Figure 1 below, the nature of sunlight changes rhythmically throughout each day—from the cool pre-dawn twilight, through the golden glow just after sunrise, to the neutral white light at noon. Then the cycle reverses itself in the afternoon as the sun continues across the sky to the western horizon and be-yond. Day after day, sunlight follows this rhythmic pattern—which gives you the opportunity to schedule shoots for a particular quality of light.
Thirty to sixty minutes after sunrise, as the sun continues to climb, its rays pass through a thinner and thinner layer of atmosphere (Figure 2). The color of sunlight shifts from warm to neutral as the intensity of the sun peaks at noon. As the intensity of the sunlight increases, so does the contrast of its shadows.
For many photographers, the extreme contrast of midday sun can problematic. Actually, I don’t think it is the light that is problematic; I think it is the skills of the photographers that create the midday challenges. There are many ways to modify direct sunlight so that you can create great shots throughout the middle of the day—the key is to reduce the contrast of the sunlight, either by diffusing the sun directly or by bouncing light into the shadows.
Intensity—high to extremely high
When the sun is above, but still near the horizon, its rays pass through a thick slice of the atmosphere (Figure 3). As the rays bounce off of dust, water vapor, and other particulates, the light scatters—taking on a very warm cast. The beautiful colors and relatively low contrast of sunlight during the golden hour makes this a great time to photograph. Golden Hour is the favorite light of many landscape photographers. Like the rush hour on an urban freeway, the golden hour is seldom exactly 60 minutes long. To blend in fill flash during golden hour, remember to color your flash with a CTO or Half-CTO gel.
Color—warm to very warm
Blue Hour / Twilight
You may have never thought of making photographs when the sun is below the horizon, but with a sturdy tripod, a high ISO, and/or long exposures, you can create captivating images during twilight. In case you are wondering; the difference between night and twilight is that at night you cannot distinguish the horizon from a dark sky and during twilight you can.
During twilight, even though we cannot see the sun directly, the sun’s rays bounce off the upper atmosphere and cascade down (Figure 4)—taking on a very blue color. So photographers often call twilight the blue hour. To blend flash with blue hour, color the light with a CTB or half-CTB gel.
Intensity—low to very low
In Part 2 (here): we will take a look at the color and quality of the sunlight during each phase.