Yes, the shutter belt still has a twist in it. The trick is simply to make the belt as loose as possible without the belt being able to jump. I've got machines here that haven't had their belts changed in 3 years and they are still trucking along fine. Granted the insides of the projectors are nasty because there wasn't belt dressing (or even Joe's combination belt dressing/FilmGuard trick) 3 years ago, but they're chugging along fine and dandy still.

(Mark and Steve, I expect a full show between you two in front of the Christie booth this week. Steve, which booth shall we have our platter vs. changeover argument at?)

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Still, a front shutter with no rear shutter would make an interesting experiment and could be easily tried on a Super or E7 or even a Century with a bit of shaft extension. Perhaps one with water cooling...

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At the very least. Shutters mounted in front of the lens disappeared from use in the 1920s when increasing projection speeds resulted in a move from three-blade to two-blade shutters, and with it a rise in lamp intensity. Two blade designs were found to be much safer because (i) the consequences of sticking your fingers in the wrong place were not as severe, and (ii) it kept the film stock cooler - a big deal, given that the film stock in use at the time was nitrate.

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The very first 35mm moving picture projectors were either combined camera/printer/projector devices such as the Lumière Cinématographe (which, when used as projectors, could not survive the heat of an intense light source and so were unsuitable for use in large auditoria) or mechanisms designed to bolt onto the front of a magic lantern (i.e. a slide projector). Placing a rotating shutter behind the gate was difficult in these setups because both the shutter itself and the mechanical linkages driving it would have fouled parts of the existing lantern.

This arrangement persisted long after there was any technical need for it, and external shutters didn't totally go out of use until around the conversion to sound, although the rethinking of projector design in the decade following WWI was what really kick-started the process. Auditoria got bigger, so the throw from projector to screen increased and the light sources used got more powerful (and thus they generated more heat). The film in use being nitrate, cooling became more of an issue and the introduction of two-blade shutters to maximise light efficiency soon followed, together with an increase in shooting and projection speeds.

Suggested reading: Raymond Fielding (ed.), 'A Technological History of Motion Pictures and Television' (Berkeley, California UP, 1957).

Contact your booth supplier for pricing regarding the motor hinge kit.

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