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Author
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Topic: Cinemeccanica Victoria 5 change run/shutter speed
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Tony Smith
Film Handler
Posts: 42
From: worcester,worcestershire, england ,UK
Registered: Sep 2012
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posted 02-14-2015 11:54 AM
Hi My colleauge wishs to run some film 35 mm shot at 20 frames per second, on a Cinemeccanica Victoria 5 with 3 phase motor, not sure if it's 4 or 8 pole. Its run via a Mitsubushi invertor, single phase in 3 phase out (50hz) type A024. Anybody any knowledge on this topic that could please help. The way I though we could do it is to run the motor slower, by around 17%. If this is possible, whats the best way to do this, to reduce the 50hz by 17% to 41.5 Hz or reduce the 3 phase voltage, or none of these.
Tony Smith
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Leo Enticknap
Film God
![](http://www.film-tech.com/ubbmembers/534a.jpg)
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 02-17-2015 11:09 AM
Hmm ... hadn't thought of using a smaller pulley on the motor shaft, but if you can get hold of one, fitting it would be very easy, and as John points out, the belt tensioner should be able to take up the extra.
As for shutters, correct me if I'm wrong, but I believe that there were at least two models of two-blade shutter made for the Vic 5 (perhaps one of them by an aftermarket supplier - not sure). The standard one was pretty easy to time and had larger blades than the "small blade" one, which was intended for situations where your lamp was essentially underpowered and you needed to squeeze every last lumen out of it. Timing the "small blade" one was absolutely critical and very difficult to prevent ghosting, but I'm guessing that it probably would be a little more flicker tolerant of sub-24 frame rates.
If you're showing full-gate silent prints using a Vic 5 installation regularly, then permanently installed three-blade shutters, lamps big enough to give you 16ft-l on a white light even with three-blade shutters installed and motors that can be adjusted between 16-25fps (25 to run the odd shot for PAL TV production, 35mm prints of which crop up in European arthouse cinemas from time to time) at the twist of a knob is an investment worth making.
You will also, of course, need lenses and plates for the full-gate silent ratio, though a workaround for that is to use the 'scope prime lens without the anamorph, which will also do for the silent and Movietone ratios (perfectly, if your masking can move at the top and/or bottom, and good enough for most people if your masking is sides only). The height of the frame in all three ratios (silent, Movietone and 2.39 'scope) is very close to identical. At the one place I worked which used Vic 5s for silent shows, we had the anamorphs on a bracket which swung out of the way to enable the 'scope primes to be used for silent and Movietone.
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