This was one of the first assignments I received in the photojournalism program at the Rochester Institute of Technology. My professor William Snyder was constantly quoting Robert Capa's famous saying, "If your pictures aren't good enough, you're not close enough." He gave us this assignment in an attempt to make us "get closer."
We were asked to hold our arm stretched out in front of us and focus on our fingertips. We then had to tape down the camera's focal ring in that exact position, making anything farther than an "arm's length" away out of focus and forcing us to get close to our subject.