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Author Topic: Three blade shutters Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 04-11-2007 08:23 PM                    I've seen three blade shutters mentioned here before, but I've never personally seen a projector that uses them. Can anyone reveal what projectors use them? Do they come standard, or are they modifications? And what is the point of them? Thanks.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 04-11-2007 08:47 PM                        Three blade shutters increase the number of light interruptions (at 24fps) from 48 to 72, greatly reducing the perception of shutter flicker, at a cost of light efficiency. Most often used in studio situations, or smaller screening rooms, where light efficiency is not the issue it can be on a large screen. Also used for presentation of silent films, which would have intolerable shutter flicker with a two blade shutter at the slower frame rates.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-12-2007 01:12 PM                     3 wing shutters are a standard for 16mm projectors since they have the two speed motor - for both sound and silent speed films. ... and also a standard for 8mm if the machine is silent only due to the 16fps speed.  |  IP: Logged Robert Throop Master Film Handler Posts: 412 From: Vernon, NY USA Registered: Jun 99 posted 04-12-2007 01:36 PM                     quote: Monte L Fullmer 3 wing shutters are a standard for 16mm projectors since they have the two speed motor - for both sound and silent speed films. I think the Kodak Pageant had a centrifugally operated shutter that had 3 blades at silent speed and 2 blades at sound speed. Bob  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 04-13-2007 02:20 PM                     Yes, it was called the "Super 40" shutter. One other 16mm projector had a similar shutter, but can't think of which one.  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 04-13-2007 02:30 PM                     Graflex made one, and Bolex made one which could be manually changed from three to two blades while running.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-13-2007 04:00 PM                     ..and your good ol' Bell and Howell's, esp the older 'suitcase' units, had a single blade counterweighted unit-like what the Christie P35 units have, but it swung around twice and on the third swing, the pulldown from the shuttle mechanism would engage.. My Viewlex 16 unit has the good ol 3 wing fixed shutter assembly - and no silent speed option. I think that Ampros used a barrel shutter arrangement, but was set up as with a larger master blade with the smaller blade opposite of the master.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-13-2007 07:15 PM                     And Kinoton beats em all...its a 3-wing below 20fps and 2-wing above...done so by their clever intermittent and shutter system in their "E" series projectors. They cheat it by spinning the shutter faster below 20fps such that the same 2-wing shutter will flash the picture 3-times before pull-down. They are not constrained by a mechanical relationship between the shutter and intermittent. 3-wing can even be configured for up to 25fps if desired for screening room applications. Just remember, when you put a real 3-wing shutter in any projector, you will loose 1/2 the light...thems the math.  |  IP: Logged Bruce McGee Phenomenal Film Handler Posts: 1776 From: Asheville, NC USA... Nowhere in Particular. Registered: Aug 1999 posted 04-14-2007 12:14 AM                     Sorry, posted deleted.  |  IP: Logged Phillip Grace Expert Film Handler Posts: 164 From: ACMI. Melbourne. Australia. Registered: Mar 2004 posted 04-14-2007 02:18 AM                     The Siemens 2000 16mm projector had a 2 or 3 blade shutter which was changed manually from outside the projector with the machine stopped. I recall the shutter openings being quite wide even on the 3 blade setting - probably due to the claw pulldown.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 04-14-2007 03:57 AM                     Kinoton E beats the hell out of projectors! FP30's with EXTREME amount of light and these projectors never get hot. Largest lamp we use is 3K  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 04-14-2007 09:01 AM                        quote: Steve Guttag Just remember, when you put a real 3-wing shutter in any projector, you will loose 1/2 the light...thems the math. Good point: I've seen many a silent film presented in a venue which has put the three-blade shutter in but not upgraded the lamp output accordingly, thereby causing a very murky picture. In answer to Mark's question, most projector mechanisms nowadays are supplied with two-blade shutters as standard, with three-blade ones available to order as a separate part.  |  IP: Logged William Phillips Expert Film Handler Posts: 117 From: Cardigan, Wales, UK Registered: Feb 2002 posted 04-14-2007 09:16 AM                        The difference a 3 blade makes is amazing. 1 of my screens has a 3 blade with a 2k lamp. The picture jumps off the screen. Having good lens on the front is a must as well. That screen has ISCO red.  |  IP: Logged

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