Focal Length and Camera-to-Subject Distance Affect the Visual Dynamics of Your Photographs
In the movie Jaws, there’s a scene in which actor Roy Scheider, playing Martin Brody, the Chief of Police of the fictitious Cape Cod town of Amity, first spots the central character of the movie: a Great White (mechanical) shark, now on display at the Aadlen Brothers U-Pick Parts in California, and affectionately nicknamed “Junkyard Bruce.”
As the scene begins, Chief Brody is sitting on a beach chair, with a nervous, tentative look on his face. The camera is head-and-shoulders tight on him, with the camera positioned about arm’s length from his nose. Because the camera’s zoom lens is set to a wider angle you can see a great deal of background surrounding his face, including beach-goers and colorful umbrellas. After a few false alarms (memorably precluded by “Da-dum, Da-dum, Da-dum,”) the shark finally makes its debut.
And here’s where the coolest zoom effect simply eats up the screen. When Brody realizes this is the real deal, he suddenly leans forward in his chair, with eyes squinting straight into the lens—as the camera quickly pulls straight back and the lens zooms correspondingly tighter into his face. His head remains the same size on the screen while the background details seemingly collapse around him. It’s the kind of cinematic wizardry that pulls you straight out of your chair and into the action.
How this “zoom-in / truck-out” movement visually plays out is that the character’s head remains a constant size within the frame lines as the background scenery seemingly collapses while the camera pulls away and the lens’s angle of view narrows. The end result is an amazing three-second demonstration on how the focal length of your lens and the distance between your lens and your subject impacts the visual dynamics of a photograph, or in this case, a motion-picture sequence.
The moment you attach a lens to your camera, you establish a set of parameters that directly determine the visual dynamics of your photographs. The way you approach and frame a photograph using a wide-angle lens is quite different from the way you’d approach the same subject with a longer telephoto lens. When taking photographs containing multiple subjects at different distances from the lens, the subject closest to the lens will loom larger in the frame than the subjects positioned further from the lens, unless of course, the subject closest to the lens is notably smaller than the furthermost subjects.
In the four photographs illustrated above the “same” scene is captured at progressively closer distances while zooming back from the zoom’s longest telephoto position (200mm) to its widest focal length (28mm). During the transition from distant and telephoto to closer and wider, the size and position of the red corn bin remains relatively constant while the size of the white privy, which is a bit further from the camera’s position, recedes into the background as the camera gets closer.
In addition to changes in the spatial relationship between the various elements in each photograph, when shooting with wider-angle optics, the background also becomes increasingly expansive in the process. Although each of these photographs is strong on its individual merits, the visual dynamics of each of the photographs differ vastly. As for which one is better or dynamically stronger is purely subjective, but as these four images attest, anything worth photographing is worth examining from differing perspectives. And don’t be surprised if you stumble upon an angle/distance relationship that produces an image stronger than the picture you pre-visualized when you captured your first frame.