Watching children play is a delight. Watching them having fun, pure fun, is God given delight.
One day, I brought my daughter to the playground. She liked to play with the swing. While she was having a whale of a time, I quickly took a snap!
Quick response, with constant tracking on the eyes are the key elements of "nailing"this shot. No other tricks required.
For the static effect, and isolation with the background, I used the E-3 with 50mm F2.0 Macro lens, and chose wide aperture F3.2 and fast shutter speed 1/400s. Even in broad daylight, I had to bump up the ISO sensitivity to 400. Fill flash was used to stop the motion.
Further post-processing in monochrome emphasized the expression of satisfaction and joy.