Yes, I know, I just did a composition post. But the last one got me to thinking, and this one is more than simply composition. Bear with me.
The compositional guideline in photography that everyone learns quickly is the Rule of Thirds. Simply put, and illustrated above, you break the frame into thirds, a tic-tac-toe board, and then place your key elements on the lines, or for preference, on the intersection of the lines. Horizons should not be in the middle, but offset to one of the two horizontal thirds lines. Instead of placing your subject smack in the middle of the frame, you get a more pleasing composition by utilizing this rule.
Except, it’s not really a rule, and most decent photographers know this (and explain it too.) There are plenty of times when you shouldn’t use it, and lots of good compositions that would be worse if it was used. While I cropped the image above to meet the rule exactly, the ratio that I actually use for prints is mildly different. And it’s not really clear how much variation you can have before the “pleasing effect” fades too much.
So, let’s get something out of the way first. What I personally recommend is to consider placing your subject off-center. A subject placed in the middle is thrown in the viewers face: “Here it is!” While placing it off-center says, “Here is a scene with a strong subject.” It allows you to show setting, establish mood and time of day, and gives the viewer awareness of the background, foreground, or surrounding areas that can make a story or idea complete. Place your horizon to emphasize the element most interesting, be it sky or foreground. So, break the rule as you see fit. Try it out, but use your judgment on where to place your subject(s).
Now, the bigger question: Why does this even work? The answer is, no one knows. There are a couple of concepts that seem to relate, the foremost being something called the Golden Mean or Golden Ratio, a simple mathematical relation used in art and design. The Rule of Thirds isn’t a match for this, but hews fairly closely. The Golden Mean has supposedly been used since ancient times in architecture, art, and various odd areas – I say supposedly because the cases that people have made for great works of art following this closely, for instance, usually turn out to be fudging the numbers by a significant margin.
And then there’s the Fibonacci Sequence, another mathematical ratio that, when applied two-dimensionally, also strikes fairly close to the Golden Mean and the Rule of Thirds, but seems to appear in nature surprisingly often. The most common illustration of this is the nautilus shell shape that appears as you increase a curve, um, Fibonaccially (whatever,) but it is also supposed to show in the placement of leaves around the circumference of a stem, allowing them the maximum amount of sunlight without blocking leaves directly underneath. Very cool, really, but in reality, this varies widely based on the type of plant, size of leaves, and environmental factors. The argument seems to be that nature has demonstrated a mathematical formula, indicating some connection between nature and math, but it appears more to be a case of bearing a passing resemblance than supporting a natural law. A lot of people like mathematics because of its precision, but mathematics is really an abstract, and doesn’t apply well to the natural world. In order to use it, you have to choose arbitrary definitions. Two oranges are always twice the weight of one orange, right? No, that’s ludicrous.
The thing is, none of the concepts does anything to explain why we find such measurements pleasing to the eye (or, in some cases, ear or touch.) The various mathematical formulas were created to match (more or less) this very common tendency for humans to respond to certain layouts, but it’s clear we’re not concerned with the exact numbers. There is something fundamental at work deep in our minds. I originally toyed with the idea that our two eyes were the culprit, having something to do with visual range, overlap, and our desire to assess surroundings. A subject right smack in front of you gains all of your attention, but can be threatening, while one offset allows you room to see something else, to escape, and so on. Sounded good, but it failed to explain vertical compositions, and would likely have led to a dislike of them entirely if it were true. Pop psychology is rarely useful ;-)
Seen here, a composition that I find very strong doesn’t align terribly well – the sun reflection falls on one of the lines, but well away from the intersection. Many other shots that I find well-composed, including most of the examples in my composition series (use the Categories link in the sidebar to see more,) meander away from these proportions noticeably. Either it is far from exact, or my judgment sucks – your call on that one ;-)
Would knowing why we tend to prefer a certain layout answer anything about us? It’s hard to say – while most of the traits we have now have some bearing to our evolution and survival, a few things are simply artifacts of our development. I doubt it’s the answer to life, the universe, and everything, but I can’t get over my curiosity about it.
The rule of thirds is only a sub-rule of a larger principle – the ratio of odd to even (which relates also to phi & the FS). In almost every field of visual design, the most pleasing arrangements have an odd number of elements – or the illusion of an odd number. The rule of thirds is an elementary way to achieve this effect, but, as you noted, some pleasing compositions bearing no obvious relation to this rule.
However, if you look closely at your beach photograph, you will see that it has an area of sand to water in an odd to even ratio. Each horizontal section roughly obeys “thirds”. If you were to subdivide it further, you would find it has thirds nested into thirds into thirds.
That all being said, I still have no idea why odd numbers or incommensurate ratios are so pleasing. That question was being asked well before Pythagorus & his buddies took it up & still is today!