Photo Study of the Roger Federer Forehand

The position of the ball tells us that Roger struck it just a tiny fraction of a second before this photo was taken. If you project backward to where the point of contact must have been, you can see how much topspin Roger must have put on the ball by noting how much his racquet has risen in that tiny bit of time. You can also get a sense of the rotational energy in Roger's swing by comparing the angle of his shoulders to that of his hips.

Roger is offering a valuable tip here with his eyes, too. The best way to make sure you see the ball well is to look at the point of contact for a split second after you've hit the ball.