To attach a camera to a tripod you have to have a connection, and that connection is made via a plate on the camera and a ball head on the tripod. The ball head must allow the camera to rotate and adopt various angles, but it must also support the weight of the camera in a secure and stable fashion. If the camera slowly sinks while the photo or set of photos are being taken, the advantage of the tripod is lost.
There’s a ball head that you can’t buy at a store that you should consider if you have a big SLR or shoot with big lenses. The Really Right Stuff ball head earns the name they gave the company. Really Right Stuff makes really great ball heads. The big knob tightens or loosens the ball, allowing it to swivel or holding it secure. The clamp on top grasps a Swiss Arca type plate with a quick and simple lever. The quality of the build is evident in the smoothness of operation and the ease with which they are performed.
I used my tripod today taking photos at a Pow Wow indoors, with relatively low light and subjects in motion…no flash allowed. My 5D s-r won’t go to really high ISO without noise, and I was shooting with a 70-200 mm f 2.8 lens. The RRS ball head was effectively acting as a gimball head much of the day since I had to track the dancers with the camera on servo mode for focus. It worked like a dream.
I own other heads, but this will be the head I use. Worth an extra pound to have this sort of instrument at one’s disposal. A slight turn of the big knob and the camera is totally secure, even when using a heavy telephoto lens on a big camera and grip. This head is rated to manage a 600 mm lens or even larger, whereas the 40 mm RRS head is rated for small to medium large lenses. I also like that it has 2 slots to allow you to drop the camera into a vertical orientation. That makes it so much quicker than a ball head with only one such slot. Being able to quickly get in position and quickly secure the camera means you won’t miss the shot when the dancer looks right at you.
You can’t get it at a store. You must go to www.reallyrightstuff.com and order it directly from the manufacturer. Mine arrived in 3 days by ground (California to Washington State). You won’t be sorry.

The Dancer looked right at me and thanks to the quick secure lock on the RRS head I got the shot off in time.

You can’t resist taking a few photos from behind since that is where the most decorative feathers are located.