What color is the light—white, red, blue…?
The color of light in your photographs provides significant clues to your viewers about the shot. You were there. You experienced the moment as you pushed the shutter button. The viewer only has the details and information within the frame. So, know that color can go a long way to affect the mood of your images. Sometimes you can change the color of light in your shot for creative effect. Other times, you have to capture the light as you see it.
Cool Light/Warm Light
A basic way to describe color is to say that it is either cool or warm. Cool colors include green, blue, and purple. While cool light can be perceived as calming, it can also be perceived as cold or depressing. Likewise, green can suggest a pastoral setting, but it can also suggest immense wealth.
Warm colors live on the other side of the color wheel. They are red, orange, and yellow. Warm light is perceived as being comforting. Warm skin tones are seen as a sign of health. However, intense red can be seen as the color of anger and also passion.
When we speak of light as being either cool or warm, usually we are describing a slight tint to the light and not saying that the light is strongly blue or orange. As shown in Figures 1.9 and 1.10, the same scene can have two completely different looks based on the time of day that it was shot. In Figure 1.9, the photo has a cool tint because it was shot with the sun just below the horizon. Figure 1.10 was shot a few minutes after the sun rose above the horizon. In the following chapter, we will talk in detail about how the time of day influences the color of light.
Figure 1.9. Shooting just before sunrise (during the blue hour) creates a cool tint to the image because the sunlight is reflecting off of the upper atmosphere.
Figure 1.10. A few minutes later, when the sun crests above the horizon, the light takes on a golden glow—which is why photographers call this time the golden hour.
Color Temperature of Light Sources
Color temperature refers to how blue or yellow a light source appears. The surprising thing is that low color temperatures describe yellowish light, and high color temperatures describe bluish light (Figure 1.11). Yet, we talk about yellow as being a warm color and blue as being a cool color. This is one of those photo-opposites—just like it’s surprising when you first learn that an f-stop with a small number is actually a large aperture opening. Scientists and lighting designers have very precise reasons for why this is so. I just accept it as stated. My mnemonic is that somewhere in my youth I learned that the blue part of a flame is hotter than the yellow part. So, light with a high color temperature is bluer than light with a low color temperature.
Figure 1.11. Color temperature describes how yellow or blue a light source appears. The unit of measurement for color temperature is “Kelvin” (not “degrees Kelvin,” as you may hear some say).
In a practical sense, you know that candlelight has a very warm (yellowish) color. What you might not know is that the color of open shade is very blue. Our eyes and brain work together to turn the brightest part of a scene to white. This is why, when you look at a white shirt or a piece of white paper under an old-school incandescent bulb, they look white rather than yellow-orange. Then, when you walk outside into the open shade on the north side of your house, the paper and shirt still look white. In this sense, our eyes and brain are much smarter than our digital cameras.
White balance is the camera setting that overcomes the color cast of a particular light source. As we will discuss in detail in Chapter 2, matching the camera’s white balance to the light source will mean that whites are captured as white rather than as lightly amber or slightly blue.
Any range of colors can be described as a gamut. There is a gamut of colors that you can see, a gamut of colors that your camera can record, a gamut that your monitor can display, and a gamut that your printer can print. To paint a simpler picture, I like to think of each of these gamuts as a box of crayons. As you’ll see below, the box of crayons gets smaller as you move through the image-making process. This is one of the reasons why a photograph of a richly colored sunset did not look as beautiful as the actual sunset.
Without getting too technical, I want you to understand the limitations imposed by our gear. So, in Figure 1.12, I’ve made a graph that compares the range of human vision to three key pieces of gear used to create the images in this book. The yellow line shows the range of colors that my camera can record. The white line shows the colors that my monitor can display. The orange line shows the gamut of CMYK commercial printing used to print books and magazines.
Figure 1.12. This gamut graph shows how human vision (the entire box) compares to the range of colors that can be captured by my Canon 5D Mark III camera (yellow), displayed on my Apple iMac monitor (white), and then printed in this book through CMYK printing (orange).
Now, take a look at the flowers in Figure 1.13. When I made this photograph, I was impressed by the super-saturated magenta of the petals. Take my word for it, the gamut of CMYK printing used to print this book falls far short of the vibrancy that I experienced in the garden. They screamed “PINK!”
Figure 1.13. The super-saturated magenta of these landscape roses is beyond the gamut of the CMYK inks used to print books, magazines, and catalogs. So, the color and texture of the petals is less vibrant than they actually were when I shot the photo.
Taking a look at Figure 1.14—a gamut graph of the photo in Figure 1.13—will help us understand what is going on. The green dots show the range of colors in my original capture (the original shot). You’ll note that there is a large group of green dots outside the CMYK gamut (the orange box), which explains why I think that the colors look dull here. It is also interesting to note that there are many dots that fall outside the gamut of my monitor (the white box). So, while my camera was able to capture a wide range of color, I could not see many of the rich pinks on my monitor, nor are they reproduced in this book. This is why the photograph printed here is much less colorful than the flowers themselves—their gamut was beyond the range of colors that can be reproduced on a typical printing press.
Figure 1.14. This gamut graph shows the range of colors in the photo as green dots. The big cluster outside the orange box represents the colors outside the CMYK gamut. The green dots outside the white box are colors captured by my camera that cannot be displayed on my monitor.
So, if you’ve ever shot a photo of a sunset or a flower that lacks the beauty that you actually experienced, it is likely that the scene contained colors that just could not be captured or printed. Don’t despair. Obviously, beautiful photographs are created and printed every day. As photographers, though, we need to be aware of the limitations of our gear and the opportunities to use lighting as a way to overcome these limitations. Also, know that the technology of image-processing software gets better every year. I’ve no doubt that someday I will be able to print the full range of colors that I saw in those roses.