I made several hundred photographs of this dancer and her colleagues during a performance of Brazilian carnival dance in Recife’s historic opera house. Dance is about poise, energy and movement, and this is the image that I felt most effectively defined this performance for me. It is rich in blur, yet clearly defines the flow of the movement itself. We can see the dancer’s expression through the blur – her eyes are closed, her face a mask of confidence and pride. She holds a doll in one hand -- it throbs with blur. Meanwhile, her other hand is held high, her arm thrust a gesture of accomplishment.

While we were visiting Tunisia, the country celebrated New Era Day, a commemoration of President Ben Ali’s coup of November 7, 1987. Ali is still in power twenty-one years later. Here his blurred image waves from dozens of flags, carried by school children singing a national song in concert on the steps of Tunis’ Theatre Municipal. I made this image by ambient light at night, using a full second to express the joyful emotions of the singing children.

Camera in hand, I was waiting for the light to change so I could cross the street in pursuit of a potential picture. Suddenly another picture opportunity exploded right in front of me. A phone rang, a woman answered, her phone in one hand, her coffee and a paper bag in the other. Her incongruous western-style boots were planted, toes-in, on one of Manhattan’s busiest avenues, and she was obviously concerned about what she was hearing. I lifted my camera and made this image, not yet realizing the full meaning of what I had been able to include in the frame. Later, when I was able to carefully inspect this image for the first time, I noticed that my frame also included a blurry bike and car. The blur implies dangerous speed, and her expression seems full of concern. Yet she stands in the street itself, well away from the safety of the curb, oblivious to such threats only a few feet away.

Kerala is a state on the tropical Malabar Coast of southwestern India. It is 1,300 miles from Delhi, where we began our trip through India, and represents an entirely different culture. This crow lifts off from a houseboat that carried us through Kerala's backwaters for three days. It was perched on the boat’s ornate bow, and lifted off as I pressed the shutter button. The fairly fast 1/250th of a second shutter speed was not enough to stop its movement. Instead I caught the blurred bird just as it was leaving the frame, giving the image enough tension to make it throb with energy.

The blue shutters are tack sharp. The speeding motorbike appears to be stopped in its tracks, but is not clearly defined. Even though I use a shutter speed of 1/400th of second here, which is very fast, it is not fast enough to completely freeze the machine and its riders all of their detail. And it is that little touch of blur here that gives the image its vitality – the machine seems to quiver in place – the profile of its driver vibrates with energy, in striking contrast to the crisply defined detail in the shutters behind him. Many photographers would scrap such an image because they wanted to “stop” the bike with clarity. I would urge them to reconsider their decision, and look at its blur as an expression of vibration and motion. And that is what motorbikes are all about.

We spent more than an hour photographing in the classrooms of this school for children with special needs. Some of them, such as this child, became so excited at the presence of my camera that she began to clap and sing with great exuberance. How best to capture this exuberance? The classrooms were dark with few windows, leaving me with but three options. I could increase the ISO and risk muddy images. I could use a flash, as other photographers with me were doing, and clearly stop the action, but in doing so, I would risk making a harshly illuminated, snapshot-like image. Or I could stay at ISO 100, and shoot the scene at a very slow shutter speed – in this case 1/5th of a second. I opted for the latter, and it worked perfectly for my purpose. Her hands are seen in both an open and closed position, simulating a clapping action. Her mouth moves as well – you can almost hear her voice. Most of all, we sense her spirit, enthusiasm, and above all, her joy. I shot her again and again, and each time I would make a picture, her happiness intensified.