I think that one of the most important things a photographer can do as he/she is looking at a subject or at images is ask a simple question, “What is this photograph about?” When you know the answer to that question on photo design, then you can decide what you need to do to make the photo clearly about what it is supposed to be about.
I see this all the time in student’s work from my classes (including at the BetterPhoto.com online photography school, where everyone submits photos for critique in each lesson). Photographic composition can get confused because the photographer is taking a picture of a subject rather than looking to see what the photograph is really about. If you photograph a subject, you simply surround the subject with your viewfinder. The problem comes if the light, color, focus, etc., does not support that photo.
You see, the viewer looks at your image not as you do (with your history of actually taking the photo and being with the subject), but as a unique entity that they can understand only from what is in the photograph. If your subject is a stream, but the light is highlighting a rock at the bottom right corner, the composition is conflicted. The viewer thinks you mean the stream, but that rock is getting a spotlight on it, so obviously it is very important (just like in the theater, a spotlight emphasizes what we should look at), so the viewer looks at that. Yet the rock doesn’t seem all that important to the stream other than another rock, so the viewer is confused.
This happens all the time. You think your subject is the bird you have focused on, but there is a bright red shape in the background (from a stop sign, perhaps). The bird has its drab winter colors, so guess what attracts the viewer’s eye - the red shape. Or maybe there is a cut-off, odd shape that is very sharp in a corner (you know it is a tree branch, but the viewer cannot tell) - that again becomes a distraction because the sharpness implies that it is important to what the photograph is about.
Another problem that can come when you are not considering what a photo is about is too much stuff in a photograph. This comes when the photographer says the photograph is about this … and this … and this - but they are all unrelated things.
So you end up with a kid holding a rabbit in one part of the frame and her brother digging in the sandbox in another part of the frame. The photo becomes confusing. What is the photo about? “Well, it is about my daughter and her rabbit plus her brother playing.” Visually, it looks like they were pasted together. There is no visual connection. If the photo were to be about both things, the answer to the question would be, “It is about my daughter and her rabbit showing how this is all part of our family activities.” Notice it is not about A plus B, but about A integrated with B, which requires a different mindset for the photograph and will more likely result in a photo that looks like everything in it belongs together.
If you start asking yourself regularly, “What is this photo about?”, it will become an automatic thing that you don’t have to think about. Ask it while you compose the shot, when you review the image in the LCD and when you look at the photo back at the computer.
Editor's thoughts: Rob Sheppard teaches a number of digital photography online courses at BetterPhoto, including Composition Boot Camp and Impact in Your Photographs: The Wow Factor. In addition, the BetterPhoto online photography school offers a number of classes in photo design