Cranks and Motors - Text 5
The Bell & Howell 2709, which was used extensively for studio work from the mid-1910s onward, also relied on a crank taking eight frames per revolution. An after-market electric motor was, however, introduced by the manufacturer in 1920. Yet, film historian Kevin Brownlow remarks that this motor saw infrequent use up until the advent of sound cinema later in the decade.[1] This can of course be partly explained by the convenience offered by the crank, which made the camera lighter and did not require the use of cumbersome batteries. But these advantages might not have been that significant for studio work, where staff and equipment were rarely in short supply.
Rather, Brownlow surmises that the manifest preference of silent-era camera operators for the use of cranks over motors was primarily attributable to creative factors. The most important of these factors might have been that the crank permitted them to constantly adapt – even in the midst of a take – the frame rate at which they were shooting. This could be done to compensate for low levels of lighting (a lower frame rate meant a longer exposure time), or to make the cinematography serve the action. Camera operators could, for instance, decide to turn the crank more slowly so as to create a sped-up effect amplifying a comedic or suspenseful moment. This habit of constantly playing on the difference between a highly variable shooting frame rate and a (mostly) fixed projection frame rate would become marginal only with the advent of sound, which required both the shooting and projection speeds to be standardized at 24 frames per second so that synchronism and the pitch of the dialogues, sound effects and musical score making up the soundtrack would not be affected.
But how can one explain the growing use of electric motors in the final years of silent cinema if the crank had such creative advantages? The answer seems to lie in the enthusiasm of the era’s filmmakers and cinematographers for visual effects. Upon the introduction of its electric motor in 1920, Bell & Howell argued that
Modern methods of picture making and presentation demand the utmost in artistic effects and frequent dissolves, fade-outs and visionary effects are very much in vogue at the present time, the manipulation of these being usually attended to by the assistant camera-man necessitating two or three to each camera. In this connection the value of the Cinemotor will readily be appreciated as it allows the camera-man ample freedom for working the auxiliary apparatus and relieves him entirely of the duty of actually turning the camera.[2]