The Five Values of Light :: Digital Photo Secrets

The Five Values of Light

by David Peterson 2 comments

Before you became a photographer, there was exactly one sort of light. It was either on, or it was off. Sure, there were varying degrees of brightness - there was dim light and there was bright light, but it was all pretty much the same thing.

Then, when you learned how to use a camera, you discovered something new. There's not just one kind of light. Light has color and direction. It can be hard or soft. It's no longer just about how bright it is - now light has quality. And what's more, that quality can make or break your photographs.

So unless you are a brand new photographer, and your camera is still pretty shiny and exciting and you haven't really figured out everything it can do yet, you probably already know some of these things about light. You know that incandescent light can have a warm orange or yellow cast to it, and the light in the shade can be more bluish. You know that side light is soft and dimensional, and that overhead light tends to be hard and unflattering. That's lighting 101, and it's all critically important information for any photographer. But now I want you to think even more about light, and how you might be able to break down the light in any given scene into its individual components.

Why is this important?

The problem with photography—and with any other art form that exists only on flat surfaces—is that it can be challenging to convey to your viewer that an image is supposed to represent a three dimensional scene. At face value, it seems like the human brain should be able to make that interpretation pretty easily—after all, we know that a photo of a tree is a photo of a tree, and a photo of a barn is a photo of a barn. But in practice, it just isn't that simple. We need visual cues to tell us that that barn isn't just a two dimensional block of red color that looks like a barn.

There are a lot of ways you can do this—you can use leading lines, you can place objects in the near foreground, you can play with depth of field—but one other thing you can do is pay attention to the light.

Good light has five values. Wait, what? You were probably just getting used to the idea that good light comes from the side, or is soft in intensity. Now I'm telling you that you have to pay attention to its values, too? Well, it’s not a requirement but you may find it really helpful to understand what it is about certain types of light that can help add that feeling of depth and dimension to an image that might otherwise look flat and two-dimensional. Those five values are responsible for creating the illusion that that two-dimensional object actually has texture, color, size, shape and surface.

Specular highlights

This term is generally used to refer to that very bright spot of light that appears on a shiny object. When illuminated, a glass sphere, for example, will have a very bright highlight on its surface, which is essentially just a reflection of the light source. This spot is important because it gives the viewer information about where the light source is, and how reflective or shiny (or dull) the sphere’s surface is. This is the first visual cue that you have for imagining that a two-dimensional object exists in three dimensions.

Specular highlights are more obvious on reflective objects like metal or glass, where they typically represent as bright white. But that doesn’t mean that they don’t exist on other objects—specular highlights on dull surfaces tend to be just lighter shades of whatever the color of that object is.


    2.1: apparent light size -- blood orange(s) by Flickr user JonathanCohen

    Diffused highlights

    You probably don’t think of the lit part of an object as the “highlights,” because we generally think of highlights as the brightest parts of a scene. But technically speaking, the rest of the object—that is, the part that doesn’t fall into shadow—is also a highlight. This part of the object scatters the light that falls on it, or “diffuses” it, which is why we call it a “diffused highlight.”

    Diffused highlights reveal an object’s true color and texture. This is the value below specular highlights, which are the brightest points of a scene and will typically mask detail. Let’s say you have a photograph of a person—some of the person’s skin is going to be in shadow, and some of it may be hidden by those specular highlights. The skin color that appears true in the image (that is, close in value to the person’s actual skin color) is the diffused highlight. Diffused highlights also reveal an object’s natural texture, so you’ll be able to see the details of clothing, wrinkles or other areas of fine detail.

    The shadow area

    This is one of the most important values for creating that sense of dimension in a photograph. The shaded side is what makes round objects look round. It is generally opposite the light source, or in a position where no light is able to reach it. It is darker than the diffused highlights are, and it can tend to overemphasize texture, that is, make things look more textured than they actually are—which can be a problem if your subject has blemishes or other skin problems. The really interesting thing about this value of light is that it contains the complimentary color of whatever the main color of the object is. For example, a yellow ball will have a shaded side with a purple tint in it.

    The transfer area

    This is not technically one of those five values, but it’s an important consideration because it’s the area between the diffused highlights and the shadows. If your subject is lit with a hard light, there will be a pretty abrupt change between the diffused highlights and the shadows, and very little of this transfer area. If your subject is lit with a soft light, you’ll get a more gradual transition between the two areas.

    • Nikon D7000
    • 100
    • f/13.0
    • 0.004 sec (1/250)
    • 120 mm

    132/365 - (Incr)edible! by Flickr user djwtwo

    Reflected light

    You may know this value as the light that you bounce into a scene to fill the shadows. This type of light is separate from the primary light source and can be used not only to fill in dark areas but also to add definition and shape to your subject.


    Retail Therapy: A Tribute to JKonig by Flickr user BrittneyBush

    Shadows

    This is different from the “shadow area” because it refers to the shadow cast by an object, rather than the shaded part of that object. Generally speaking, an object needs some sort of shadow, because that shadow helps to establish the object’s place within its surroundings. It can also tell your viewer something about the texture of those surroundings. For example, if you place an object on a cobblestone street, the shadow that object casts is going to be defined by the shapes of the stones. This is important for giving an image some context, and to ground a subject in its environment.

    Conclusion

    I want you to go back and take a look at some of your most successful images, and ask yourself if you can see those five tonal values in them. I think you’ll find that your answer will be yes, because having those five qualities in the light can really go a long way towards making an image more compelling. Now go back and look at some of your less successful images and ask yourself the same question. Are any of those values missing?

    Now take this knowledge out into the field. If you’re shooting a subject you can take your time with, think about whether or not you can spot those five values of light in the scene you’re about to photograph. If not, do some playing. Bounce light into the scene with a reflector. Change your position so that the specular highlight and the shadow side have more prominence. Make sure that the object is casting a shadow and that there is a smooth and gradual transition between the diffused highlights and the shadow side. Get the hang of doing this consciously, so that it will start to happen on a subconscious level, every time you look at a scene.

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    Comments

    1. Anna Grobler says:

      I read this twice it was so interesting.I'm definitely going to use this information.
      Thankyou

    2. Telma says:

      Thank you so much for your time, writing these awesome lessons! I appreciate it a lot! They are so informative and helpful!

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