Your eyes and your camera don’t see the same thing. Your eyes zero in on the main subject and ignore everything else, while the camera sees everything in the frame equally. Even the best photographers can miss a distracting element in the background if they’re concentrating on a compelling subject (a face, flower, bicycle, doorway or patch of light).
To see what your camera is going to see, it’s helpful to scan the entire image in your viewfinder before pressing the shutter. Take it in stages, first look at the subject, then at the background, and finally check the edges of the picture to make sure no objects are cutting in on the picture.
Look for bright spots, strong colors, lines or shapes that are competing with the subject for attention. Pay special attention to any areas of the background that may be tangent to the subject. Things that are small but have strong contrast or are very bright may take up only a small portion of the frame but still compete strongly for attention.
Once you’ve found any distracting elements, move around the subject or change the angle or perspective from which you’re shooting the subject and see if you can separate them. Sometimes, taking just a step to the left or right can separate a pole or other vertical object from the subject. Lowering your viewpoint might allow you to shoot past a table and hide a cluttered shelf or a group of objects in the background behind the table in the foreground. Move closer to the subject to leave the objects out of the frame, or farther away to include only a shadow or plain wall. Other times, changing your angle just a few degrees can open up an area of clean, negative space behind a subject.
Depth of field can also help hide details that are distracting, but only after you’ve consciously composed the image and placed strong shapes and bright spots in the right areas of the image.
Do this exercise to learn to see and manage the whole frame:
Choose a subject, then take two photographs of that subject, one after the other. Take the first photograph quickly, without changing your viewpoint and while concentrating only on the subject. For the second photograph, slow down and look in your viewfinder, scanning from corner-to-corner of the image looking for things in the background that might be a distraction—bright spots, strong lines or shapes that are tangent to the subject, things touching the edges, etc. Then, move your viewpoint slightly to eliminate or change the position of the strongest distraction in the frame and take a second picture.
Look at the two pictures side-by-side on a big screen, to see how much a minor shift in perspective can make a difference. In post-production, you might darken bright spots, or crop out distractions, but by doing so you may also crop out negative space or lose balance and symmetry in the composition. Software doesn’t easily fix an unsightly pole that appears to be growing out of a person’s head. Solve problems like that in your camera before you press the shutter, for clear, distraction-free images.