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Topic: Apeture plates

Jack Theakston
Master Film Handler

Posts: 411
From: New York, USA
Registered: Sep 2007

posted 07-11-2008 09:50 PM

I agree, if you are running below the threshold of 24 fps, a 3-blade shutter is almost mandatory. And yes, in the day, silent films were tinted AND black and white, which did absorb a lot of light. But keep in mind, screens were also much smaller back then, too.

Steve, I don't have the SMPE papers in front of me right now, but I do have my 1922, first edition of James R. Cameron's Motion Picture Projection, an invaluable resource to those interested in theater operation of the era. He streamlines SMPE's standards for all things motion picture in these two pages:
http://www.thephotoplayer.com/standards1.jpg
http://www.thephotoplayer.com/standards2.jpg

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Andy Frodsham
Expert Film Handler

Posts: 238
From: Stoke on Trent, Staffs, UK
Registered: Nov 2006

posted 07-12-2008 01:38 AM

Sorry Eric! On the basis of your last posting it sounds like I've been trying to teach my grandmother to suck eggs!

That's the last time I try to be a smart ass!

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Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002

posted 07-12-2008 03:52 AM

There were several 16mm projectors where the shutter could be adjusted between 2 and 3 blade. The Bolex S221 did itwith a simple lever, labeled '2' and '3', which could be changed while the machine was running, some models of Graflex had a shutter which could be changed by manually sliding 2 of the blades together and locking them together with a small sliding catch, and there was a machine which made the change automatically when the speed was changed. Was anything similar ever done on 35mm machines during the transitional period from silent to sound?

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Jon Miller
Jedi Master Film Handler

Posts: 973
From: San Diego, CA, USA
Registered: Sep 1999

posted 07-12-2008 02:43 PM

The Super-40 shutter used in many Kodak AV-126/256 and 250-series 16mm projectors would automatically switch between two to three blades when projection speed was changed. The centrifugal mechanism sometimes would get balky with age, though, causing more flicker if the movable blades stuck in mid-position.

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Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000

posted 07-13-2008 05:50 PM

On the speed issue, herewith some VERY rough and ready pointers:

Hollywood was running relatively fast by the early '20s. From what I can gather the big picture palaces with large auditoria and long throws called for as much light as it was possible to get, hence a move from 3- to 2-blade shutters and an increase in projection speeds. 24fps was the norm by the middle of the decade, a point which is made by several people in the published papers in the SMPTE Journal and elsewhere over the standardisation of the projection and shooting speed during the conversion to sound. Pretty much anything from Billy Bitzer's mega-slow shooting to well into the 20s could have been used before the end of WWI.

Europe - From the late teens until sound, 18-22fps is typical, except Germany, which kept shooting at 16fps right up until sound.

Agreed totally with earlier posters that archives should do the research (as far as is possible) and specify a projection speed - or if the ideal or intended speed is in dispute, at the very least provide the projectionist with a note in the can detailing the best known information.

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