It is challenging to take a decent picture of a swan. Their bodies are white the water is dark, beyond the range of most films or discs to capture. A camera makes a guess at averaging the exposure. However, if one understands the principals and has a spot meter, it is possible to nail the f stop and speed.
This swan was across a pond, by a bank, feeding under over-hanging willow branches. In and out of filtered light, on the move, slowly. A 500mm mirror lens on a 35 should reach out to the graceful bird. This lens is difficult to hand-hold, belongs on a tripod, but I needed flexible movement, inches, up and down, side to side.
I learned an infantry snoozing technique in enemy territory. Sit on your butt, rifle secure on your lap, knees up, head down, locked with arms; when awaking, no jerking up, sudden movement, alerting a sniper.
A camera and its mirror lens resting on a human tripod were able to follow the swan. First, spot-meter readings are taken. Exposure set to just retain detail in the white and hopefully not lose too much in the dark, critical.
The lens followed the curving creature, click, click, click, auto winding then. 24 exposures, one superb shot, one wet ass.