MOS vs. Sound Camera

MOS stands for Missing Optical Sound, but has many other presumed meanings such as "mit out sprechen" or "mit out sound". Basically it means that the film will have no associated synchronous audio track. A MOS camera is one that cannot be used for shooting synchronous sound, they are not intended to be used with recorded sound and thus operate much louder. Since MOS cameras are not made for recording sound they are usally not as bulky as sound cameras, which have sound deadening materials used in their construction. That does not mean that a MOS camera is inferior to a sound camera, but they are used for different purposes, such as shooting at high FPS rates, shooting in reverse, or single frames.