Film-Tech Forum ARCHIVE: Stange white lines in top picture ??

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Posted by Henrik Sanden (Member # 1222) on 11-03-2002, 03:16 PM:

A few weeks ago we got a copy of Tripple X. Just after each cut in the movie, a white line appears in the top of the frame. Why ?

Posted by Tim Reed (Member # 137) on 11-03-2002, 03:30 PM:

Sounds like splice marks in the negative. If this is a scope picture and the film is only slightly out of frame, or if there's a bit too much of the frame showing on the screen, you'll see the negative splice marks.

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Better Projection Pays!

Posted by Dave Williams (Member # 299) on 11-03-2002, 03:32 PM:

I have seen this most frequently with FOX features. What studio is XXX from? I have seen it from all, but most FOX pictures have this problem. It makes it kind of impossible to get the entire true frame on screen.

Dave

Posted by Jon Bartow (Member # 241) on 11-03-2002, 04:20 PM:

Tim!
Northampton, PA?
Please e-mail me and tell me what has been happening with you.
Jonathan Bartow

Posted by Scott Norwood (Member # 30) on 11-03-2002, 04:27 PM:

Sometimes this is visible in some reels and not in others. Apparently this is a result of bi-directional printing, where the picture will be shifted slightly "up" or "down" depending on which reel was printed in which direction. For some reason, "Enigma" was really bad in this respect and needed to be re-framed at every reel change. And, no, the negative splices shouldn't be visible on screen if the aperture plates are cut to spec.

Posted by Randy Stankey (Member # 64) on 11-03-2002, 04:55 PM:

When polyester film was popularized the method of splicing had to change. You can't use cement to splice poly. Editors and lab operators had to switch to ultrasonic splicers. (A fancy form of using heat to fuse the two pieces of film together.) Those splice lines, be they chemical/cement splices or ultrasonic/heat splices do show up in the final print when the negatives are duplicated.

When that happened, the width of the splice line got just a hair-bit wider. In order to compensate for that, SMPTE declared that aperture plates be made just a hair-bit smaller (in the vertical dimension) to cover the white mark left by the wider splices.

This is not a problem with FLAT prints because only SCOPE prints will use the whole frame. FLAT prints only use (approximately) HALF the area of each frame. Fat frame lines don't matter.

What is likely to be happening to you is one of two things:
(Or both)

Your aperture plates are still filed to the old standard and the fat frame lines are showing through when you come to a scene/camera change.
You are framing your picture just a hair-bit too high or low. Try adjusting your framing knob just an wee bit up or down and see if you can't make it go away.

True, some films may have bad, out of place or non-standard frame lines which will exacerbate the problem. In which case you probably just have to live with it and be secure in the knowledge that 90% of the people out there don't have the "mental bandwidth" to recognize it.

If it's just one or two prints every once in a while, don't worry about it. There's not a lot you can do. IF you have this problem a lot, especially if it happens on more than one projector in your complex, call your tech and have him make you new aperture plates to the new SMPTE standard.

One final thought: Might you have a gremlin in your theatre that likes to file aperture plates?

Posted by Gordon McLeod (Member # 33) on 11-03-2002, 05:19 PM:

Ultrasonic splices are narrower than cement splices

Posted by Tim Reed (Member # 137) on 11-03-2002, 06:21 PM:

quote:
Editors and lab operators had to switch to ultrasonic splicers.

Isn't polyester used only in release prints?

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Better Projection Pays!

Posted by Steve Kraus (Member # 476) on 11-03-2002, 07:46 PM:

Negative splice lines may sometimes become visible but only on Scope release prints made from anamorphic negatives. They are there on 1.85, 1.66, and 1.37 prints as well but the projectable area comes nowhere near them, unlike on Scope. And Scope prints made via the Super 35 process won't have them because the negative is cut and spliced before the optical blowup is done and of course the extraction area is also nowhere near the splice, although you may see occasional lines if changes were made after the blowup and cut into the anamorphic IP. Otherwise each frameline is clean whether its at a scene change or not.

Posted by Demetris Thoupis (Member # 833) on 11-04-2002, 08:50 AM:

Why does everyone keep thinking technical when there might be a simpler answer. What if the picture was a bit out of frame?

That would explain why the white line appears. If the picture's top frame was just underneath the apperture plate then that white line would appear. It depends on the cinema.
Demetris Thoupis

Posted by Steve Kraus (Member # 476) on 11-04-2002, 09:44 AM:

Framing is clearly a part of the answer...with properly filed aperture plates one does not see the white lines from negative splices unless one is slightly out of frame. But if by your comment you are suggesting he's simply out of frame and it has nothing to do with negative splices please refer back to the original question because he specifically says he is seeing the lines ONLY after each cut in the film. Also, the normal frame lines on contact printed material are black but are often white on Super 35 blowups because the blowup is usually done from cut camera negative (the "EK") to IP. The tiny unexposed area between anamorphic frames on the IP will be clear after processing...then contact printing to dupe negative it will be black...then contact printing to release print it will be white. So going extremely out of frame on a Super 35 Scope release you'd see a white line while on true anamorphic you'd see black (just as you would on any other format but you'd have to go a long long way out of frame to see it projected) but with momentary white flashes at the scene changes and these are just barely out of the projectable area.

Posted by Aaron Sisemore (Member # 145) on 11-04-2002, 11:00 AM:

>>Isn't polyester used only in release prints?<<

I have handled unmarried Estar work prints and Estar dailies, and am pretty sure that all other production stocks (except for the camera negative itself, which has to be 'breakable' in case of a potentially expensive and disastrous film jam inside of a camera) are now Estar based.

Dave W.: XXX is from Sony.

-Aaron

Posted by Tim Reed (Member # 137) on 11-04-2002, 11:47 AM:

Aaron, I'm sorry, that's what I meant... that negative stock wasn't polyester. Randy said everyone had switched to ultrasonic splicing, but they wouldn't have to, in order to cut the negative.

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Better Projection Pays!

Posted by John Pytlak (Member # 331) on 11-04-2002, 03:16 PM:

Camera original negatives are almost always on triacetate base. Negative cutters use cement splices, typically made on a classic Bell and Howell foot-operated splicer, or a heated tabletop splicer like a Maier-Hancock:
here ACVL Conforming/Splicing Tips

Duplicate negatives used for release printing use either triacetate base or polyester base. With modern high speed printing, polyester base is usually preferred by the labs. Splices between scenes are RARE in a duplicate negative:
here Kodak VISION Color Intermediate Film
here Kodak Intermediate Film Catalog

SMPTE Recommended Practice RP111 specifies the dimensions of splices, and notes the need for less overlap (dimension A) when splicing anamorphic negatives. However, some labs/negative cutters prefer the greater reliability of a slightly wider splice, which can result in visible splice lines at scene changes.

Splice lines can be completely eliminated by using A/B roll printing and "checkerboard" splicing with "zero cuts" when printing the spliced negative:
here ACVL Invisible Splice Technique

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: here

Posted by William Leland III (Member # 1400) on 11-04-2002, 03:49 PM:

This might be what you are talking about or a different problem but certain prints we showed had "White Lines" on the top of the screen, but it happened everytime a scene changed. all we did was frame it up alittle. problem sloved. it was an annoying problem and only certain prints did this.

Posted by John Pytlak (Member # 331) on 11-04-2002, 04:06 PM:

The pulldown for each frame is 4 x 0.1870 = 0.748 inches. Standard SMPTE 195 specifies the height of the "scope" projected image area to be 0.690 inches, leaving only 0.748 - 0.690 = 0.058 inches for the splice overlap not to show.

SMPTE RP111 specifies the splice overlap (Dimension A) to be 0.049 inches for laboratory splices, but recommends "To minimize projection of splices, the width of the laboratory splice should be no greater than 0.040 in (1.02mm)". Annex A4 of RP111 says "CinemaScope splices can be made with an overlap of as little as 0.030 in (0.76mm)".

As I noted, there are well-established negative cutting techniques that can be used to have "invisible" splices.

Posted by Leo Enticknap (Member # 534) on 11-05-2002, 04:46 AM:

Why the film industry can't do something about the issue of camera jams necessitating the use of acetate really bugs me. Deacetylation is a well-known problem and even if you store an element in ideal, FIAF-recommended temperature and humidity conditions, it's going to decompose eventually. In some cases 50 years will be enough for it to shrink so far that it can no longer be contact printed. So even now, we're creating original elements with a built-in limited life. The studios are spending hundreds of millions of dollars producing an original film element which cannot be preserved in perpetuity (not in the best quality possible, anyhow).

Surely there is a technical solution that would enable polyester to be used in cameras? For example, how about fitting cutters to the bottom of each magazine which would be triggered by a sudden increase in pressure?

Posted by John Pytlak (Member # 331) on 11-05-2002, 07:26 AM:

Kodak does supply some color negative and reversal camera films with ESTAR base. For example, EASTMAN EXR 100T Color Negative Film SO-256, KODAK VISION 500T Color Negative Film SO-579, EASTMAN EKTACHROME Film 2239, etc. Uses include 65mm IMAX cameras used in space, and high speed instrumentation cameras. I agree that cameras could be engineered to deal with the strength of polyester film, and ultrasonic splicing could be optimized for use in conforming negative originals, but triacetate base still seems to be preferred for today's production system.

Of course, protection IPs and DNs can be made on KODAK VISION Color Intermediate Film (ESTAR Base) 2242, and separation positives on KODAK Panchromatic Separation Film (ESTAR Base) 2238:
here 2242
here 2238

Posted by Tim Reed (Member # 137) on 11-05-2002, 12:33 PM:

What's always bugged me is that not many seemed very concerned about film jams in the projectors.

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Better Projection Pays!

Posted by John Pytlak (Member # 331) on 11-05-2002, 12:49 PM:

Unlike some other film manufacturers, Kodak has consistently recommended tension-sensing failsafes between the platter and projector when using polyester film. IMHO, the best designs allow some slack using a movable "trolley", allowing the projector to coast to a stop if an abnormal tension buildup shuts things down.

Posted by Tim Reed (Member # 137) on 11-05-2002, 02:32 PM:

I know you do, John. I have, too. I meant as related to using polyester base film to begin with.

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Better Projection Pays!

Posted by Leo Enticknap (Member # 534) on 11-06-2002, 03:23 PM:

There is a certain irony here. Polyester is, as far as is known, the best possible base for long-term preservation because it is inorganic and there are no known decomposition issues. But the one thing it is not used for are camera original elements!

One particular feature of acetate is that, like paper, it will tear if subjected to abnormal stress, thus discharging the pressure. Its main weakness is that it decomposes over many years. In a 'normal' projection film path environment - i.e. platter and projector - that pressure can and does cause serious damage. But what is the most common usage of polyester stock? You guessed it, release prints. Acetate would be fine for release prints, because 99.9% of them have a lifetime measured in weeks, not years.

Posted by Steve Kraus (Member # 476) on 11-06-2002, 08:47 PM:

What is the long term longevity of polyester? Do we know for sure or only accelerated life tests? Is it like Sydney Stratton's miracle polymer in The Man in the White Suit?

Posted by David Stambaugh (Member # 1102) on 11-06-2002, 08:59 PM:

This is very anecdotal to be sure, and not directly related to film. But anyway, Williams Electronics started factory-applying Mylar (polyester) playfield protectors on some of their games in the late 80's. A year ago I bought an NOS crated playfield that was manufactured in 1989 and stored for 12 years in a warehouse with no environmental controls. After 12 years in storage, the Mylar was in perfect condition, had not yellowed or otherwise deteriorated in any way. All the rubber rings were of course completely rotted.

Mylar playfield protectors are also very difficult to remove. The stuff is incredibly strong (no news there).

Posted by John Pytlak (Member # 331) on 11-06-2002, 10:08 PM:

Polyester film has been used since the mid 1950's, in a variety of storage conditions around the world. Unlike nitrate and triacetate, I have not seen any ESTAR base degradation ever reported, but perhaps Leo or other archivists here on Film-Tech could relate their experiences or any reports of degradation.

All IMAX prints have been on ESTAR base print film since the early 1970's.

AFAIK, most airline prints (e.g., In-Flight, Transcom) were made on polyester base film.

Here is a link to information about "vinegar syndrome" with triacetate base that has been stored improperly:
here

Here is general information about film base:
here
------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: here

Posted by Demetris Thoupis (Member # 833) on 11-07-2002, 02:10 PM:

I bet my job on that white lines only showed when u played a scope film. Prove me wrong!

Demetris Thoupis

Posted by Steve Kraus (Member # 476) on 11-07-2002, 11:38 PM:

Regarding molecular sieves, they really only serve to absorb decomposition products from film stored in sealed containers, right? It would seem that if one keeps film well ventilated then it's just as well or better than a roll in an enclosed container with a molecular sieve.

Has anyone come up with anything more proactive for materials where the base is starting to go, such as rewashing with something that will neutralize the acid?

Posted by John Pytlak (Member # 331) on 11-08-2002, 07:58 AM:

Yes, the Molecular Sieves adsorb acid vapors and moisture, and the film and Molecular Sieves need to be in a sealed container. Molecular Sieves are so effective in adsorbing moisture that you can actually measure a weight gain within a short time of being exposed to the open air! Weight gain can be used as a measure of when the Molecular Sieves are saturated and need to be replaced.

Fully vented containers also can be used reduce build-up of damaging acid vapors. Of course, then you need to condition the entire storage area to the recommended (SMPTE RP131) low relative humidity of 20 to 30 percent for optimum long-term storage.
here Molecular Sieves

Posted by Leo Enticknap (Member # 534) on 11-08-2002, 10:17 AM:

First off, I've never heard of any evidence to suggest that there are base decomposition issues with polyester. Steve's point is a valuable one - just because we don't know of any issues does not mean for sure that there aren't any. After all, nitrate decomposition wasn't discovered until the 30s, and there was no systematic research on VS until the 70s. But we do know that there are definitely serious issues with all of the alternatives, hence polyester is now the archival storage base of choice.

As for molecular sieves vs. vented cans, there are pros and cons with both. The sieves need to be inspected and replaced regularly, but as the can is sealed, there is no danger of offgases contaminating any other element in a vault. As John points out, vented cans (e.g. Dancan or Stil) are only any good if temperature, humidity and air circulation are up to the job of removing the fumes. If not, then offgases from a badly decomposing element can accelerate the process in one which started out in a much better state.

Posted by Owen Shave (Member # 1156) on 11-08-2002, 01:27 PM:

if its worth anything, I noticed the same thing with a copy of xXx.
The white lines were quite tight top and bottom and although their was plenty of room really, sloppy projecting could have resulted in their being visible on screen. Of course they did not see the light of day in our booths. (we have no windows).

Owen