John Suler's Photographic Psychology: Image and Psyche
Cropping is probably the fastest and easiest way to dramatically alter the composition of a photograph. The more difficult issue - and one that you could spend quite a bit of time considering - is how exactly to crop it.
You could start by addressing what some people believe are the three most important rules about composition: simplify, simplify, simplify. If there are things along the edges of the shot that don’t contribute to either the visual aspects of the composition, or to the subject matter, then crop them out. If something detracts from the shot, like an unsightly utility pole, then definitely eliminate it.
Highly skilled photographers who have developed a keen eye for composition often frame a precise shot as they take it, thereby capturing an image that contains all the essential elements of the scene and nothing more. Such fortuitous photos will require no fix.
For the rest of us, we might have to crop. Even if you have a keen eye, it might be a wise practice to frame the shot a bit wider than you might think is necessary, just in case there’s something on the periphery of the main subject that could enhance the image, even though you didn’t realize it at the time. The human mind tends to zoom in on what it thinks is important and overlooks what “seems” extraneous. For example, you might go in for a close-up portrait and not realize that trees along the sides of the shot could have framed the subject nicely, or that the people in the background add an element of interpersonal interest. If it turns out that the wider shot was unnecessary, that there isn’t anything on the periphery of the image that enhances it, you can always crop later in your image editing program.
Framing a shot as you take it is really a type of cropping. After all, there’s a 360 degree environment all around you. By taking the shot, you’re slicing that panoramic reality down to a particular scene within it. In your image editing program, you’re refining that crop even more. In both the camera and your program, you’re asking the same basic question: What do I want to isolate and emphasize in this scene?
In some cases you might radically crop the image (in the camera or your program) until it enters the realm of “dépaysement” or abstraction. For example, you crop so tightly into a fork on a plate that you extract it from the context. It takes on a life and meaning of its own, perhaps independent of ideas about food and eating. Or your super-tight crop reduces it completely to an abstract pattern of lines and textures that only vaguely indicates “fork.”
Other types of crops, although less dramatic, can nevertheless improve an image significantly. You might crop to enhance the balance, proportions, and geometry of elements in the shot. Let’s reduce that sky a bit so that it’s about twice the size of the landscape. Or you might crop to place a subject in a rule of thirds position. Or to place that person’s eye at a captivating dead center. In traditional portraits, rather then letting a subject float uncomfortably in the middle of the image, use a crop to attach the person to the frame.
In some cases cropping can radically transform the meaning of a shot. One person in a couple can be eliminated to make it appear that the subject is alone. Removing a smoke stack can make a forest seem perfectly pristine and untouched by human hands. Cropping out shorts can create the illusion that a bare-chested man is naked. In these cases, cropping entails a process of reducing, purifying, or simplifying. For artistic purposes, such alterations of the image may be perfectly acceptable. In the case of photojournalism or other images that should be presenting a factual reality, the crop could be an objectionable act of deception.
In photography the term “aspect ratio” refers to the relative size of the width and height of the image frame. In many SLR cameras the ratio is 2x3. To print in 5x7, 8x10 or other standard sizes, you’ll have to crop the original shot. It’s good to keep these standard aspect ratios in mind when you take the shot as well as when you start to crop it in your image editing program. Some crops work well for some types of photos, but not others. For example, a portrait might work well in 8x10 landscape orientation but an actual landscape shot will look a bit chopped off on the sides.
When preparing images for computer displays, we don’t need to worry about the traditional aspect ratios of prints and the metal, plastic, or wood frames that hold them. You can crop to any width-to-height proportion that you like.
Here it helps to understand how that proportion affects the perception of the image. Very tall frames emphasize and even exaggerate the height of the subject. They create upward movement. On the other hand, very wide frames generate lateral movement and a sense of panoramic vista. The extra long frame of a panoramically stitched image encourages the eye to pan and scan laterally, just as the eye would normally behave when viewing an expansive scene, such as a landscape. An aspect ratio that echoes the proportions of some object within the image might not be consciously perceived by the viewer, but subliminally it can produce a pleasing feeling of balance and predictability.
Although they lack a sense of vertical or lateral direction, which might pose a problem for some compositions, square crops convey a feeling of solidity, groundedness, and certainty - while crops that are slightly off square betray those sensations and make us feel a bit lopsided and uneasy. Composition strategies for a square frame might struggle to escape its rigid geometry. For example, its strict shape tends to direct the eye to the center of the image, which may not suit the intended composition. Most subjects also have a distinct direction of width or height, which we often try to align with the corresponding edge of a rectangular frame, but a square frame offers no distinct direction for echoing the dimension of the subject. On the other hand, square frames work well for radiating patterns, circles, other perfectly symmetrical objects, and patterns or textures which have no obvious direction.
If classical theory is correct, then the Golden Ratio of 2 to 3 will be aesthetically satisfying to almost everyone, perhaps due to the fact that the human eye, which works via binocular vision, tends to experience the world in the horizontal proportions of the "landscape" oriented 2x3 frame. Perhaps this is why it's a common aspect ratio for cameras. In the vertical orientation, the 2x3 frame may work fine for such subjects as trees, buildings, and standing people, but it may seem uncomfortably tall for closer portraits, as if we're turning our heads sideways to see the subject. A crop may be needed. The 2x3 frame feels much more natural in the landscape orientation, and in that sense does not affect the composition in any remarkable way. There is a tendency to place objects on a horizontal line in this type of frame, with objects lower in the image, which creates a feeling of stability. Placing a subject higher tends to create the sensation of it floating or that we're looking down on it. Some photographers believe that the slightly "fatter" 3:4 aspect ratio, as you might see in some point-and-shoot digicams, feels even more unobtrusive than the 2x3 frame, and therefore has even less impact on composition.
Filling the frame, or not, is an essential question when both taking and cropping the shot. If elements of the surroundings adds interest to or helps explain the subject, or if they improve the composition, then don't eliminate them. Stacks of metal surrounding a welder will drive home the nature of his work, as well as provide leading lines that point to him. Space around subjects gives them more "room to breath," while cropping the subject tighter to the frame takes us in for an up close and personal encounter. In some cases a tight crop will indeed feel tight, restrictive, perhaps even claustrophic, which may or may not serve the composition. Cropping to attach a subject to the frame might help secure and ground it, but cropping that puts edges of the subject close to but not touching the frame might be distracting.
Some practical considerations. Remember that the more you crop into an image, the more resolution you will need to keep the image sharp. This is where high megapixel cameras come in handy. You’ll be able to crop more while still preserving the clarity. And always remember to save the original. Later on you might change your mind about having eliminated that foreground of street litter, or having cropped Uncle Joe out of the family portrait because he was picking his nose.
If you liked this article in Photographic Psychology, you might also like these:
The Big Picture of Composition
The Rule of Thirds