Cinematography-Theory-And-Practice

Crane/Jib ArmA crane is any camera support where the arm can rotate freely as wellas boom up and down. For nearly all cranes, there is a pivot point,and behind this point are counterweights. This is different from adolly, where the boom arm is fixed and operated by hydraulics. Ajib arm generally means a smaller crane arm that is mounted on adolly or sticks. Most jib arms do not have a seat for the operator andcamera assistant; the camera is operated from the floor or perhaps ona small ladder or an apple box.The counterweights extending behind the pivot point have twoimportant consequences. First, it is important to take this backswinginto account when planning or setting up a crane move. If thereisn’t sufficient room, at best your moves will be limited and at worstsomething will be broken. The second is a safety issue, and it is onethat cannot be emphasized enough. Any crane can be dangerous.When you are on a crane, the key grip or crane grip is in charge.Nobody gets on or off the crane without permission of the cranegrip. The reason for this is that your weight and the camera weightare precisely counterbalanced by the weights on the back end. Ifyou were to suddenly get off the crane without warning, the cameraend would go flying up in the air and very likely cause damage orinjury. With anyone getting on or off, or with any changes in equipment,the crane grip and the back-end grip communicate loudly andclearly so that every step is coordinated.Two other safety issues when working on a crane: Wear your safetybelt. Always and be extremely careful around any electrical wires.After helicopters and camera cars, cranes around high-voltage wiresare the leading cause of serious injury and death in the motion pictureindustry. Take it seriously. The best bet is to tell your crane gripwhat you want and then just let him be in charge.Crane OperationCrane operation should always be a three-person job; anything lessis absolutely not safe. (This does not apply to jib arms, which don’thave seats for the operator and AC.) The key grip usually guides themove; another grip pushes and pulls the chassis, and a third grip is atthe rear of the crane with weights.This grip helps the key swing the arm and serves as a damper to cushionthe end of the move, so that the inertia of the crane doesn’t let itovershoot the mark. A good crane crew executing complex moves isa joy to watch. They make it look easy, but it calls for power, coordination,careful choreography, and nearly ballet-like precision.The ArcAnother issue with cranes is that, because they pivot on a centralpoint, any crane arm (or any dolly arm) moves in an arc, not alonga straight vertical line. In most cases this is not a problem. It onlybecomes an issue with very tight shots with limited depth of focus.Very few rigs allow you to compensate for the arc. The camera supportslides back and forth on rails.Chassis Left/Right or In/OutThe chassis is a dolly or specially built platform that supports thecrane. Most small and medium-size jib arms or cranes mount eitheron a dolly or a braced rolling platform similar to a dolly. The chassismay roll on a smooth floor or may be mounted on dolly track formore repeatable movements.Figure 11.24. A fully tricked out carrig with camera mounted on a hostesstray on the driver’s side for runningshots.camera movement221