Film-Tech Forum ARCHIVE: Ramping up projector speed to get more Sessions in...

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Posted by Stephen Brown (Member # 292) on 11-29-2003, 05:24 AM:

All,

I saw a movie in one of the local theatres tonight and I am 99% sure that they had ramped up the projector speed to make the session run faster. Now I'm not talking a small amount, it seemed almost ludicrous at times to hear the Audio. The movie was Elf, and if you've seen it you will know that the voices are already at a high pitch, but the speed up this theare did was absolutely ludicrous.

My questions are...

-Is this a widespread practice?
-If it is, Whats an acceptable amount?
-Do you think its ethical? I mean I felt ripped off having to see the movie this way. With Cinemas already battling the DVD/Video Game battle, is this another blight on the already crappy presentations that we see these days?

This may be in the wrong forum, if it is I apologise. I'm just trying to see if this is another nail in the coffin of Film/cinema.

Regards
Steve Brown

Posted by Peter Mork (Member # 1336) on 11-29-2003, 11:11 AM:

Is it widespread? I doubt it - most equipment installed in theatres today would not give you the option to raise or lower the speed. But they can sometimes go off-speed of their own accord. If you noticed this, I'd mention it.

If it was done on purpose, I wouldn't call it ethical. But take a look at this: www.cinemaweb.com/silentfilm/bookshelf/3_ettow3.htm
It's an essay from the old silent days, when such practices were considered normal. I especially like the part which discusses cutting footage out of a print to make it fit the program length. Those were the days.

Posted by John Walsh (Member # 168) on 11-29-2003, 03:54 PM:

I would agree with Peter; most equipment wouldn't allow the speed to be changed. The only 'common' exception I can think of is a older 35/70mm projector with the option to increase the frame rate to 30fps.

I have never noticed this done on purpose, but if someone did, I'd say it was certainly unethical. I have seen where a few people chopped out a large section of the ending credits to save time. One instance was during "Superman."

Posted by Mike Olpin (Member # 1115) on 11-29-2003, 04:11 PM:

Good idea, John! Im going to go hack off every other frame of the matrix credits now.

j/k [Big Grin]

I wonder what that would sound like?

Posted by Jeff Stricker (Member # 224) on 11-30-2003, 06:50 AM:

We used to vary the speed of motors in professional tape decks by powering them from a variable frequency audio oscillator. The oscillator fed an audio power amplifier (with appropriate power output to run the capstan motor) and the audio amplifier output fed the motor. Run the oscillator at frequencies >60Hz and the motor runs faster, set the oscillator frequency <60 Hz and the motor runs slower. This could be done with a MP projector, but the amplifier would probably need to be in the 300 W class.

Posted by Frank Angel (Member # 248) on 11-30-2003, 08:23 AM:

quote:
Good idea, John! Im going to go hack off every other frame of the matrix credits now.

Mike, why stop at the THE MATRIX credits? Talk about a film that needs to have "padding" removed! Those old projectionists really had the right idea....grab that splicer and fit that sucker into your schedule! heh heh. And believe me, they would have no trouble chopping out huge sections of THE MATRIX which are not only irrelevent, but freakin unintelligble. As Mr. Richardson said. I can't remember the time when I have seen a production on the screen that would not be benefited by eliminating footage. Padding operates tremendously to the damage of the show.... How right he was. Come to think of it, there are LOTS of films that could benefit from Mr. Richardson's approach to film projection.

You know how when you're sitting in the theatre and the picture goes out of focus or is misframed, the audience yells, "Projectionist....Projectionist!"? (as if there is anyone up there -- better they should yell, "Automation....Automation.") Well many, MANY times I sit and watch a film and want to scream, "Editor....Editor!" for the same reason. Coincidently, I just watched MATRIX RELOADED with some friends and throughout the film wondered if they actually forgot to hire an editor, to say nothing of a script writer who wasn't on crack. Some of those kung-fo type fight sequences seemed to go on and on for half the film.

As much as today the studios execs would have brain hemorages if theatres edited their films, still you have to admire the old dudes' dedication to making the show look the best. The guy is talking about hours and hours of prep to clean the film, do their editing thing so they don't have to speed it up. Real showmanship, albeit a little twisted when it comes to hacking up the feature.

Posted by Steve Guttag (Member # 268) on 11-30-2003, 10:21 AM:

Boy are some of you naive. Even back in the 70s and 80s, I knew of a theatre just outside of Baltimore that, with ordinary Century projectors, used slightly larger motor pullies to speed up the shows. Nobody EVER called them on it.

As to modern projectors...Any that use a motor controller has the "flexibliity" to alter the proper projected speed. Even with the good old Simplex and Century projectors one can alter the pullies (motor pulley is the easiest) to increase the speed, if they were so inclined...however...on a Simplex a simple change from the 18-tooth pulley to a 19-tooth would result in a 5.5% increase or just over 25fps.

Now, of course, with a changeover theatre...the projectionist/manager can just "play editor" on the last show to leave early...while I've never done it...I do know of others that have. Every industry has its low-life.

Steve

Posted by Charles Everett (Member # 889) on 11-30-2003, 12:34 PM:

The General Cinema Blue Star in Watchung NJ was a 4-plex that speeded everything up. I walked out of Set It Off when I realized 10 minutes in that it was speeded up. (Hint: First scene after the opening title, a party's going on, "Flash Light" by Parliament is on the soundtrack.)

Thankfully this theater was closed in 1998, torn down and replaced by a Kohl's apparel store. Shed no tears.

Posted by Leo Enticknap (Member # 534) on 12-01-2003, 02:51 AM:

At one arthouse/rep venue I worked at which shall remain nameless, we showed Seven Samurai one night. The shows always began at 7.30pm, and the evening usually concluded with a pint in the pub before we all got our respective trains home.

All pubs and bars in England stop serving alcohol at 11pm (it's the law). Seven Samurai runs 195 minutes, so it doesn't take a genius to work out that we'd be cutting it a bit fine that night. I was resigned to abstention for that evening and laced up reels 1 and 2 ready to go. Then my boss came in and asked if I'd turned the speed up. 'There shouldn't be any need to', I replied, '...we haven't been showing any silents recently.' 'I don't mean that', replied the boss. 'This fookin' Japanese pile of poncy chickenshit's going to keep us here past closing time if we don't do something about it.' He then proceeded to turn the inverters on both machines up to 30fps!

I protested a little bit, pointing out that this was one of London's leading arthouse venues (allegedly), that a lot of the customers were very knowledgable film buffs and that we'd surely get complaints. The boss replied that he'd been showing Seven Samurai at 30fps for years and no-one had noticed! 'The Japanese talk in high-pitched voices and run around all the time anyway,' he explained. 'No-one will know the difference.'

He was right - they didn't! We had one complaint only, which was that the subtitles did not stay on the screen long enough for the customer to read them!

Posted by David Favel (Member # 1125) on 12-01-2003, 02:25 PM:

A cinema I visited last year had a Kineton I think with a fps control on the side. They ran allways at the upper limit. Any faster & the dialogue wasn't in sync.
One extra session per day.

Posted by John Pytlak (Member # 331) on 12-01-2003, 02:59 PM:

David Favel wrote:

quote:
Any faster & the dialogue wasn't in sync.

How would frame rate affect sync?

Posted by John McConnel (Member # 2000) on 12-01-2003, 07:36 PM:

One of my small-town theatres had a back-up generator which was run once a month. One night after drinking a little too much beer, I raised the generator's frequency from 60 hz. to 62.5 hz. to see how much it would affect the running time. It shortened it about 5 minutes. The air conditioning seemed to work better, too. Think how much a large circuit could reduce its payroll and utilities if it did this!

Distributors might need to send frame-rate checkers with their customer checkers to see that projection speed is in order.

The venerable Fox in Detroit installed a variable-frequency drive (VFD) to enable them to vary the frame rate. Their intent wasn't to reduce the payroll or utilities, however, but to easily accommodate the proper frame rate (16 - 24 -30) of whatever they were showing, most of which are classics. The VFD also provided a gentle start-up.

Posted by Daryl C. W. O'Shea (Member # 1303) on 12-01-2003, 09:22 PM:

quote:
How would frame rate affect sync?

Very slowly. [Smile]

If you were to thread your sound head 20 frames ahead, having sound 1/24 second (~50ft) before the picture, you'd only have 1/48 second (~25ft) by the time you hit 48fps. Of course you'd never notice a change in sync since you'd be, rightly so, complaining about the picture speed and high pitch.

Posted by John McConnel (Member # 2000) on 12-01-2003, 11:13 PM:

quote:
-----------------------------------------------------------------
How would frame rate affect sync?
-----------------------------------------------------------------

I'm afraid I can't see how frame rate could affect sync at all.

Posted by Ken Lackner (Member # 1002) on 12-01-2003, 11:23 PM:

How would speeding up the frame rate affect digital sound? Would it become higher pitched the way optical would, or would the digital drop out if it wasn't being read at the proper speed?

Posted by Dave Macaulay (Member # 813) on 12-02-2003, 12:04 AM:

The sound at the projector should be a bit early to compensate for the distance from the screen to the audience, because the speed of light is rather faster than the speed of sound. If I'm 50 feet from the screen, the sound has leave the speakers a bit "early" to arrive at my ears when the light from the accompanying picture gets to my eyes. We can safely approximate that the light arrives instantaneously.
The speed of sound is about 1000 ft/sec, so this is about 1/20 second for a 50 foot distance... the sound should be 1.2 frames advanced at 24fps. Speeding up the projector - which won't change the 1.2 frame sound advance - will reduce the time represented by that 1.2 frames. The sound will be that much earlier at my seat than it sould be.
This will probably be imperceptible for any speed-up that I wouldn't notice otherwise. But speeding up the projector will be affecting the sound sync.

Posted by Warren Smyth (Member # 1838) on 12-02-2003, 12:39 AM:

In the days of Western Electric universal bases, the power to the motors was controlled to maintain consistant voltage to ensure correct sound speed of 24fps. This was accomplished by a control unit for each motor which had a generator on the motor shaft. This provided feed back voltage by which the control unit was able to monitor and control output voltage to the motor, to mainain consistancy. The line voltage could vary, but these wonders of electronics for their day, would ensure that Jeanette Mcdonald and Nelson Eddie were right on key.

Now these units had a switch where by the projectionist could switch from REG (regular) to VAR (variable). You've guessed it, by swiching to variable, control of the speed of the motor could be incremented by a potentiometer mounted at the top of the unit.

I cannot say it was a wide spread practice, but I know that five minutes or so was carved off sessions at times so that patrons could catch their buses after the performance at night. These were the days when shorts were run on the first half and one auditorium would hold one or two thousand patrons.

Incidentally these control units produced facinating results when a vacuum tube failed. The motor would race and the projectionist would dive across the room to switch into variable control to bring the speed back. The teeth on the large sprocket of the Ernemann provided a strobescope for speed. When the teeth appeared to move in reverse slowly the machine was at about 24fps. If one of the other set of tubes in the unit failed, the motor would run slow. I have often marvelled at the sophistication these control units at such an early period.I think they date back to the late twenties - at the start of sound

Posted by Leo Enticknap (Member # 534) on 12-02-2003, 01:34 AM:

Ken: I raised this very question (how does digital sound deal with slight variations in film transport speed) on another thread without any reply, and raised it with Darren over a beer on Saturday. The answer is that Dolby digital will tolerate a +/- 2fps variation in speed, and will reproduce the track by 'stretching' or 'squeezing' the duration of playback in the digital to analogue conversion, without affecting the pitch at all. If the speed goes above 26 or below 22, digital sound dies and drops to SR. In that case you would, of course, hear a change in pitch and I'd have thought you would hear the change very clearly, given that it would be the equivalent of a 12% speed change. I don't know what the margin of error is for DTS or SDDS, but I imagine it would be something similar.

Posted by Stephen Wilkinson (Member # 1463) on 12-02-2003, 07:14 AM:

From my reading, DTS can only increase to 25 f/s before reverting back to SR. It has something to do with the timecode being 30 f/s. As mentioned SRD can speed up to 26 f/s, anymore than this and it will drop out, reverting back to SR.
From my tests when SRD runs at 26 f/s the pitch does increase, and of course the gaps between words are shorter but only because of the speed up, which you would get in analogue, not due to a higher data rate.
SRD can still "WOW" like a tape machine. If you have a sound drum on a projector that has a bit of drag on it the SRD will "WOW" just as in analogue. (not as much, but will)
Most NEW projectors have speed controllers, especially Kinotons, 24 f/s, 25 f/s and 30 f/s settings. Most that I have come across in servicing are set to 25 f/s! Generally due to the crazy session requirements put on exhibitors (independent ones) by the film distributors here in Australia! (but that's another story for a different forum thread)
So if you've got a 3 phase motor on your projector it will probably have a speed controller.
stephen

Posted by John Pytlak (Member # 331) on 12-02-2003, 07:56 AM:

Dave Macaulay wrote:

quote:
This will probably be imperceptible for any speed-up that I wouldn't notice otherwise. But speeding up the projector will be affecting the sound sync.

Thanks. But the implication was that the sound sync was off enough to be noticeable if they ran "at the upper limit" for speed. A fraction of a frame sync difference is not significant.