A method detects the beginning of combustion in an internal combustion engine having several cylinders, form a rotation speed signal determined for a shaft of the engine. In one implementation, a video to be protected is temporally desynchronized and spatially desynchronized. During a frame cycle, data held in a first portion of the pixel array in the imager is clocked out of the imager using an imager clock signal, and data held in a second portion of the pixel array is bypassed. The traverse, comprising a truss connected by the traverse hinge to a frame which is by the slings connected to the load, is suspended on the second hoist cable passing via the traverse roller to the hook mechanism.