Color Vision 8: Color Saturation

Digital sensors and various types of in-camera processors are not neutral observers--many "add" something to the color record in terms of "saturation," or the richness and vividness of how the color is rendered. The degrees of saturation can be termed as neutral, saturated, and highly-saturated.

Which would you pick as the best version of this closeup floral? The top image was processed to yield a richer saturation from the original image (below). While both could stand on their own, the emotional effect of the color and rendition is considerably different. Your choice is a matter of taste and intent, but it's one that you can make either when you expose or process the image later. 

So-called "neutral" recordings are supposed to record the color as seen by the human eye. This supposedly objective stance is of course a subjective one, as everyone sees color somewhat differently, and the digital record is an approximation of what we see, at best. "Neutral" color is used mainly for portraits--where an exaggerated skin tone is undesirable, and by commercial photographers who need a true color record of, say, a sweater for a fashion spread.

Saturated images boost color and generally add more intensity to the colors in the scene. (In essence, the colors are "juiced up".) The decision to make saturated images depends on the subject matter itself. For example, you might want to add saturation to nature scenes, florals or even graffiti on walls and other graphic images, but there is no hard and fast rule. This saturation can also amp up scene contrast, which can actually be an added benefit.

There are a number of ways to alter the saturation in exposure. One is to choose JPEG over Adobe RGB color space, something you do in the camera setup menu. The former generally renders color more richly than the latter, Adobe RGB being a format chosen by those who tend to do their saturation-adding and other controls in processing later.

Another is to go to the camera’s “picture styles” menu and choose a picture “mode”  like “vivid.” When you do so you might notice that certain colors are rendered more boldly than others. High-frequency colors--such as brightly-lit red, yellow and orange—tend to enrich more than others and look as if they've just received a bright coat of paint.

The choice becomes clearer when you have a more graphic, colorful image. The top photo was made with a "neutral" camera setting but does not display the true vividness of the scene. By boosting saturation in camera settings, or doing so later in processing, all the colors "pop," the sky becomes a brisker blue, and overall image benefits. Part of this comes from the fact that adding color saturation also adds contrast to the image, giving it more "snap" and clarity. 

To test your camera’s “default” saturation level, and the effect of adding algorithms from the saturation menu, pick a colorful subject--such as fall foliage--and shoot using all the options. The simple "Blue sky/green lawn/red umbrella" test is a time-honored way to make comparisons. Once exposed, play them back one after the other and you’ll see the effect, or better yet download them and check them out as large images on the screen.

Given that we have a choice of different color saturation levels, how do we put that information to use in the field? The simplest response would be to use a high saturation effect when you want to boost color--such as with graphic scenes--and a lower saturation effect when you want a more muted (some would say more naturalistic) record--such as a rural landscape. But you could also exploit the higher contrast of the more saturated effect on overcast days (to increase contrast in flat lighting), or the lower contrast of a more neutral effect on high contrast lighting days.

Of course, the saturation options become even greater when you process your images. In fact, many programs allow you to boost one color (family or range) only, or to bring up blues and green and mute reds, yellows, and so forth. That way you can have very subtle and unique ways to alter the image.

This photo was made on a foggy autumn day in New York's Central Park. The bottom photo is the original as recorded in the camera. The top photo received a boost by increasing saturation in the yellow color only, thus enhancing the scene without sacrifice its atmospheric mood.  

One last word about saturation: excessive saturation sticks out like a sore thumb. Garish colors, which may work for graffiti, look just that—overly done—in a nature scene. Juicing can be effective, but doing so with restraint is the best course.

Next: Color Balance