While professional cameras tend to have a ring, dial, or switch for everything, less expensive cameras may have assignable rings and dials you can customize to fit your shooting style. If you’ve got two assignable controls, we suggest assigning focus to the most easily adjustable control, and assigning iris to the secondary control. These are the two most frequently changed settings while shooting a scene. If you’ve got just one dial or ring, we suggest assigning focus to it. As exposure should be able to be set using your menu system before you begin shooting a given scene, and is less likely to need adjustment.