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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » SMPTE vs. the real world

   
Author Topic: SMPTE vs. the real world
Brad Miller
Administrator

Posts: 17673
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 06-05-1999 04:07 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
So the standard SMPTE PA-35 (RP-40) test film is supposed to be the standard "reference" test film. Ok, fine.

That being said, can anyone explain why EVERY film is then printed "out of frame" when compared to the PA-35 loop??? The only film I've ever found to match is the analog THX Broadway trailer. But again, if you adjust your framing for perfect SMPTE specs and perfect "blue box" on the THX, the rest of your presentation will be low of center in the frame.

Anyone else notice this? Any theories?

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 06-05-1999 04:33 PM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
I have noticed this. I went around and adjusted all of my framing to be perfect, and then I locked the knobs down so that they would never move. (Threading out of frame at my place is a big no-no). Then my senior tech comes in one day and for some odd reason we were running RP-40 and he says "That's too high, it needs to come down." So for fun I unlocked the framing knob and moved it down. Of course when the movie came on, it was seriously too low! The THX Broadway matches RP-40 standards and so dos the Mann Theatres Policy trailer (in scope, anyway). Just adjust framing with a good green band (make a loop) -- but remember, all green bands are NOT created equal, so make sure you have a good one!

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Brian Paymer
Film Handler

Posts: 31

Registered: Jun 99


 - posted 06-20-1999 01:03 AM      Profile for Brian Paymer     Send New Private Message       Edit/Delete Post 
I have noticed this myself. I don't have THX trailers but I just figured I had a bad batch of SMPTE test loop.

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Brad Miller
Administrator

Posts: 17673
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 07-11-1999 03:08 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Here's another idea. How about printing several feet of the SMPTE PA35 test film on the head of every feature film? That way we can see just how unstable current polyestar stocks and film printing is!

I can run a loop of PA35 film on my Century JJ and the picture is as steady as a slide, but when I put some actual film (Deluxe labs in California is the worst) the picture bobs and weaves. This is magnified even more on a Christie projector, where there is bobbing and weaving on the PA35 alone.

Interestingly though, I can take an older film dating back to the 70s and 80s and they play ROCK SOLID!

Where's the quality control nowadays? Anyone else notice this? You can identify the Deluxe CA prints by the slashes through the title on the tail leader. Technicolor labs print the title in big block letters. Deluxe in Canada actually prints "made in Canada" on their tails.

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Christopher Seo
Jedi Master Film Handler

Posts: 530
From: Los Angeles, CA
Registered: Jun 99


 - posted 07-11-1999 05:31 PM      Profile for Christopher Seo   Email Christopher Seo   Send New Private Message       Edit/Delete Post 
I take it the test film is also polyester. But how can a lab's processing contribute to a print that runs unsteadily? How much of it is the fault of the manufacturer of the stock? Unfortunately I have never seen a steady picture on the brand new Simplexes we use. Shaking on the THX trailers is especially noticeable, but what that suggests I don't know...

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Brad Miller
Administrator

Posts: 17673
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 07-11-1999 05:46 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Check it out for yourself. Locate a Deluxe CA print and compare it with a Technicolor print. You will see the difference.

Just make sure you compare flat vs. flat or scope vs. scope. Flat movies will always shake worse due to the larger blowup required to fill the screen.

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Gordon McLeod
Film God

Posts: 9450
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 07-16-1999 06:07 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
Printing speed and slippage between the neg and print will create an unsteady print
The faster the printing speed the greater the jitter

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Christopher Seo
Jedi Master Film Handler

Posts: 530
From: Los Angeles, CA
Registered: Jun 99


 - posted 07-17-1999 07:06 AM      Profile for Christopher Seo   Email Christopher Seo   Send New Private Message       Edit/Delete Post 
Ah, I see. So what happens is that Kodak gives the polyester base its characteristic unsteadiness, Deluxe creates unsteadiness in the alignment of the printed images themselves, and the result is a pretty bad image.

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Gordon McLeod
Film God

Posts: 9450
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 07-17-1999 11:25 AM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
The estar base in itself isn't unsteady it is the fact that most trap assemblies can't hold it steady. This hasn't been a problem din studio's and on most european projectors like ernaman and kinotone as there gate/traps have either velvet or delrin rails or bands
Being thinner it is also more prone to heat flutter than triacetate also the emulsion doesn't stick as well to it
The bottom line is estar is here to stay so why can't northamerican projector manufacturers designing around it. They are on the end of the chain not the other way around. E7's Motiographs and Century C's seam to have no problems with it, so I think it is probably the economics of making cheaper projectors in NorthAmerica that is at fault

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Brad Miller
Administrator

Posts: 17673
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 07-17-1999 04:31 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
The biggest problem with Estar base films is the curl. That's pretty much it.

Take a foot long strip of film. Lay it down on a flat surface emulsion down. See what happens? Only the edges of the film come into contact with the surface and the picture is arched upward. This is a "base curl". All prints before the switch to polyestar stock had an emulsion curl to them. I spoke to a gentleman at Deluxe a few years back about this and in the simplest words, this is caused during the drying process of manufacture. He said it COULD be done the other way and he didn't know the reasons as to why polyestar film was done in that fashion. He seemed knowledgeable, but not interested in changing.

Also, let's say you have a film with a base curl. Winding it onto a reel emulsion in (so the base side is outward) will exaggerate this and make the film run harder and be less pliable, because the more curl there is to the film, the stiffer it will be. If the same film is wound onto a reel emulsion out, it will actually flatten out the film, making it run smoother. This is why I always rant on people who run soundtrack down on platters. Before the introduction of Estar films this could be done, as triacetate stock was pretty forgiving. But, the soundtrack should always be wound up with polyestar films to prevent this from curling more. As for changeover theaters, I modify my takeup belts with an "S" so both reels spin counter-clockwise/emulsion out.

I have ran tests with running polyestar films backwards (to simulate an emulsion curl) and even a Christie projector runs them nicely.

Thus, Gordon is right, it isn't the Estar stock which is at fault. It is the labs for processing it with a base curl.

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Brian Paymer
Film Handler

Posts: 31

Registered: Jun 99


 - posted 07-18-1999 03:33 PM      Profile for Brian Paymer     Send New Private Message       Edit/Delete Post 
I tried running a trailer backwards. It wasn't night and day, but it definitely was steadier backwards and upside down. The projector ran quieter too.

It figures Kodak would recommend to wind prints in a manner which will facilitate problems. Their advice on using PTRs isn't worth a dime, why should this be any different? I'm going to take a print and wind it soundtrack down to see how quickly the base tightens up.

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