I have shot (and played and have the surgery scars to prove it!) a lot of tennis in my life. You need at least a shutter speed of 1/250 sec to stop action, 1/000 sec is better. The backgrounds can get very distracting with all the spectators so try to keep the depth of field at a minimum. I shot these images of Steffi Graf, Gabriella Sabatini and Pam Shriver at the Bausch and Lomb Championships at Amelia Island a number of years ago, 1989 to be exact. I used a monopod mounted F2 w/ motor drive, 300mm f/4.5 AIS Nikkor @ f/5.6 (only 2/3 stop down) with High Speed Ektachrome, ASA 160 and manual "follow focus". Tennis is a very challenging sport to photograph, especially in the days before autofocus because the players are constantly in motion and move over a fairly large area. And when you are shooting at a large aperture to get separation from the spectators, who are always close, it only compounds the level of difficulty. Often you are dealing with only 2 feet of depth of field tops with a 300mm lens. You kind of get into a "Zen" mode where you block out everything else and just pay 100% of your attention to what is in the viewfinder. A fire could have broken out behind me and I would have been oblivious to it. It takes a lot of practice but anyone can learn to do it. I did not have my 300mm f/2.8 at the time or I would have used f/4. If you use a lens with a tripod socket, make sure you leave the friction loose so you can rotate the camera 90º quickly I believe I was using my 80-200mm f/4.5 non-AI Nikkor for the shot of Pam.