Depth cues are perhaps the most impactful visual elements in photography because environmental objects provide viewers with additional context and clear meaning. Newspaper producers know that the viewer’s eye is first drawn to the large images, then to the caption, headline and finally the story. If the only thing the viewer sees is the image, then it needs to convey most of the story’s meaning. Visual depth cues are one of the most basic strategies photographers employ to improve how photographed are interpreted by viewers.
How eyes and the brain interpret visual data
Visual interpretation happens simultaneously on two different levels. Human eyes see color, form, depth and movement before the brain begins the slower cognitive processes of vision. These four major visual cues are basic compositional theories every photographer needs to know to consistently create memorable images. Since photography communicates messages, knowing how to maximize the natural workings of the human eye increases the legibility of content. In other words, it’s easier for viewers to figure out what’s happening in your images.
There are eight visual depth cues: space, size, lighting intensity, textural gradients, interposition, perspective, time and color.
Environmental objects provide sense of space
Filling the frame with the downtown Minneapolis skyline is a tempting compositional choice. After all, the scene opening the article is a picturesque view of the skyline with a lovely pond in the foreground. However, not including any foreground elements from Loring Park is not the most effective way to make the skyscrapers really stand out. The eye doesn’t see immediate points of interest because there’s nothing to guide the eye. Additionally, from this location the skyline is too far away to make a visual impact.
Using the branch and benches in the foreground puts the park space into its environmental context. The shade, another visual depth cue, produces an additional layer. The benches and man produce yet another layer that frames the top two-thirds of the photograph. Tree branches on the top left provide another small frame for the skyline. Instead of downtown looking absolutely tiny, including these elements provides the eye a comparison that helps interpret distance. All of these elements create interest and utilize depth cues.
Size is everything (sorry fellas)
Knowing the actual size of an object makes it easier for the visual cortex to interpret size and determine distance. A good example of this are images of small objects that are photographed with coins so that it is easy to compare size. Although we don’t know the exact height of the man in the image above, it is clear that he is essentially at the same distance as the large painting. The placement communicates to the viewer that the middle painting is larger than life. If the man wasn’t included, viewers are less likely to realize its scope, or infer why the little girl was captured by it.
Varied lighting intensities create 3-D effect
Light intensities that vary also act as depth cues. Photographing the dog sleeping in a sun beam from the side and using a smaller f-stop emphasizes the shadows. Although this image isn’t as deep as the skyline from a park, the contrast created by the sunlight and exposure gives the portrait a three-dimensional look and feel.
Changes in lighting intensity are just about everywhere, especially in outdoor shooting locations. Always lookout for lighting conditions and take advantage of those opportunities.
Textural gradients fade into the distance
Difference in the sizes of the same of object-type create the illusion of depth. The trees in the foreground area are larger and easier for the eye to discern detail. When the eye travels toward to the top of the image, they become smaller and then eventually become a indiscernible blob of dark green coloring.
The road is also an example of the form type of visual cue. The line it creates leads the eye from the bottom to the top. Additionally, the color of green in the foreground is much lighter than the green in the background. These two elements are additional visual depth cues that accentuate the textural gradient. This is a good example of how depth cues work in conjunction.
Magazine designers love interposition
Graphic designers commonly use interposition when designing magazine covers to create depth cues. Models are placed in front of a headline or title in order to create a three-dimensional illusion. Downtown Minneapolis interposed with winding oak branches in the foreground creates a frame, emphasizes the distance of downtown from Hiawatha Park and provides the same effect.
Visual depth cues for another time
There are eight visual depth cues in total but perspective, color, and time are all topics for another occasion. They warrant individual articles that do these topics justice for the reader. Gestaltists can wait. However, we have already had some fun using forced perspective.
Masting depth cues will advance your photography immensely. We recommend going out on specific photo shoots to practice each one. We’d also love to see the results. Feel free to post them in the comments!