Part 1 in this series, explained the importance of “depth of field” in conveying a sense of three dimensions in a photograph. The next three tips are useful when taking pictures with great depth of field – like landscapes. In these images, using shallow depth of field is not an option, because of the necessity to have as much of the scene in focus as possible.
So how does our eye/brain interpret distance in scenes with extreme depth of field?
The technique suggested in this tip is based on the visual phenomena called “convergence of lines”. Lines that our eye/brain recognize as being parallel in reality, but visually merge at a vanishing point within a picture, provide us with the critical cue that distance is present, and that the scene does not exist on a single flat plane.
Pictured above is the classic “train tracks disappearing into the horizon” image. We don’t need to be engineers to understand that, in order for a train track to work, the distance between the rails MUST remain constant. Any time lines appear to defy the laws of physics by converging, as in the picture above, our eye/brain interprets this clue as distance in the picture. As a result, the picture above not only exhibits the 2D elements of height and width (defined by the borders of the picture), but also the missing third dimensional aspect of depth as provided by the converging lines of the train track.
Similar to the train tracks, the convergence of the sides of the highway (above) is perceived as depth and conveys a sense of great distance to Mt. Saint Helens in the background. For the viewer, it’s impossible to resist the sense of the third dimension and to be brought visually into the picture.
The convergence of lines in the picture above is subtler, but remains a very powerful cue for our eye/brain to perceive depth in the picture. The width of each step decreases as the eye travels up the stairway. Since this “can’t” be the reality, we interpret each smaller width as being farther away. In total, the stairway’s converging lines ad the element of three dimensions to the picture.
As you may have noticed, using converging lines as a photographic tool to instill a 3rd dimension also provides an added bonus. Our eyes will naturally follow converging lines into the scene. It’s irresistible. Managing converging lines will add the 3rd dimension and draw your viewer into the picture. How about that? A twofer.
In Part 3 of this series another of nature's visual cues, atmospheric perspective, will be discussed to understand its role in lending a sense of depth in photography.