Yesterday I wrote about shooting sports, and mentioned about shooting with big (e.g. 1/2.8) aperture often gave more dramatic results than shooting with smaller (e.g. 1/5.6 ) aperture. The reason behind it is because bigger aperture decreases the depth of field, making only part of the picture clear so that the focused subject stands out. I am here to illustrate the effect using the following pictures.
In the first picture, the focus is on the player who is trying to score a goal. Other players in the picture are blurred:
Now the attention is clearly on the soccer ball. Will it go in?!
The drama reaches the conclusion when the ball enters the goal. So the focus is still on the ball, plus the goalie, but blurred people on the background certainly enhances the drama.
How to tell the camera quickly where to focus when everything is moving so fast is no trivial matter, and it's also where the fun is:-)