Focusing is an important part of shooting a good photo alongside with composition and lighting. Focusing on static objects is relatively easy either by manually focusing or by using the camera auto focus feature. Focusing is much harder when the objects are constantly moving.
There are many techniques used by photographers in order to take in focus sharp photos of moving objects. Here are a few of them:

· Infinite focus: When the objects are far enough from the camera focus can be set either manually or automatically to infinite. As long as the moving objects stay within the infinite focus range the photo will be sharp and clear. Although this is applicable in some scenarios it is not useful in many others such as shooting sport events or air shows.

· Manually correcting the focus: Using this method the digital camera is put into manual focus mode. Focus corrections are done manually by moving a focus ring n the lens or pressing focus in and out buttons. When the objects move and change their distance from the camera the photographer manually corrects the focus as needed. This is good in some scenarios where the objects are moving relatively slow and their movement is predictable. Manually correcting the focus for objects that move very fast or move unpredictably is not practical.

· Single focus mode: When using this method the digital camera is put into single focus mode. The camera will automatically focus on the object when the shutter button is pressed. This method can be combined with the manual focus method. The photographer manually focuses on the object and the camera is executing the final focus fixes when the shutter is pressed and the photo is taken. This method is limited to either slow moving objects or high end fast focusing cameras. Focusing is a mechanical process and takes time. If the camera takes too long to focus by the time it is focused on a fast moving object the object will move and the photo will not be in focus anymore.

· Continuous auto focus: In this method the camera is put into continuous focus mode. Once the shutter button is pressed and as long as it is held half way down the camera continuously focuses on the objects in the photo. In this method the camera continuously corrects the focus as the objects distance from the camera changes. This method is very useful. Even if the object is moving fast the camera can track its movement and continuously correct the focus. By holding the shutter button half way down and continuously moving the camera to follow the moving object the camera will continuously keep the object in focus. When you are ready to shoot the photo simply press the shutter button all the way down. One drawback of this method is high power consumption as the camera continuously corrects the focus it uses the power hungry motors in the lens in order to move the optical components.
Taking good photos of moving objects is not easy. It requires practice and experience. In addition to making sure that the objects are in focus you have to continuously consider the composition, the changing lighting conditions, shutter speed to freeze or capture movement, the changing zoom and more. Go and practice shooting a lot of moving objects photos. By shooting a lot of photos in different situations you will grow the instincts that will make all these processes and considerations an unconscious automatic process.