The merger of this tree with Dave's head is so obvious, you probably think no one could avoid seeing it before snapping the shutter. Remember: we see things in three dimensions, so it's easier than you might guess to focus our eyes on the principal subject only and not see that background at all. Avoiding mergers is our sixth guideline for better composition.

You can be sure the camera always sees mergers, so look for plain backgrounds before you pose your subject. In this case the correction was simple because the two settings were only a few feet apart.