As described in Chapter 6, the skeleton is divided into axial and appendicular portions (see Figures 6.1 and 7.1). The axial skeleton is structured from 80 bones segregated intothree major regions: the skull, vertebral column, and thoraciccage (Figure 7.1) . This part of the skeleton (1) forms the lon-gitudinal axis of the body, (2) supports the head, neck, and Chapter 7 The Skeleton 199 7 Figure 7.1 The human skeleton.
Above: Some cameras have a switch to set it to auto or manual focus. Manual focus, meanwhile, disables autofocus and enables you to adjust it yourself. This is useful when the focusing system can't find focus for whatever reason, such as when it's too dark or when there's little contrast in the scene.
QuickGuide to Accurate EOS Autofocus 1 2 3This guide will provide tips on how to ensure that you and your EOS cameras and lenses can focus accurately and consistently. This is most important for lenses that have a very narrow plane of acceptable sharpness (depth-of-field).lthough the plane of focus and the cameraâs imaging plane have not changed their relationship with each other, both planes have changed in relation to your subject.If your lens is set to a small aperture it may provide enough depth-of-field that this backwards shift in focus may not be apparent.