Film-Tech Forum ARCHIVE: Wavy lines

This is topic Wavy lines in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Joe Redifer (Member # 3) on 08-03-1999, 05:13 PM:

I have a question:
What the hell are those horizontal wavy lines that sometimes come and go on a certain reel of some movies? I assume this is the labs fault, so why hasn't anything been done to correct this? I was told by one guy that it was caused by a guy at the lab wearing a striped shirt! Yeah, that must be it =P
It annoys me greatly and I'm sure annoys the audience as well. It must be stopped.

Posted by Gordon McLeod (Member # 33) on 08-03-1999, 05:21 PM:

One cause can be the film winding unevenly so that each layer is at a different hight and then being flattended out by wand in effect puting horizontal cinches

Posted by Christopher Seo (Member # 7) on 08-03-1999, 05:46 PM:

I think I've seen horizontal cinch marks... sort of like raindrops falling horizontally? But I don't think I've ever seen wavy lines.

Posted by Mike Blakesley (Member # 26) on 08-03-1999, 07:03 PM:

I think he's referring to a lab problem. It isn't scratches...it looks like a wavy pattern of darker/lighter that moves down the screen for brief moments. Looks almost like a cinema version of TV interference would.

I've noticed this happening more frequently lately...thought there was something wrong with the projector at first, but it happens only on certain movies and only at certain moments, so its gotta be the film.

Posted by Gordon McLeod (Member # 33) on 08-03-1999, 07:45 PM:

One thing I have found as also distracting is when you get the image of the heat pattern from the xenon lamp showing up in a bright scene

Posted by Gordon McLeod (Member # 33) on 08-03-1999, 07:46 PM:

One thing I have found as also distracting is when you get the image of the heat pattern from the xenon lamp showing up in a bright scene

Posted by Mark Ogden (Member # 43) on 08-03-1999, 08:20 PM:

I think I know what you're talking about, this turns up on "Runaway Bride" about the fourth reel or so, the scene where Julia Roberts and Joan Cusack are having a talk in the beauty parlor, it's just that one scene. I have no idea what this is, it can't be a printer problem because it's just that one sequence. Trouble in the original photography? Maybe a problem with the camera shutter? Hard to belive, but possible, I guess. Look carefully and you'll see a wavy light-dark-light waterfall effect throughout the scene (unless it's just us, but we've got two
prints and it's on both in the same scene). Anybody else see this?

Posted by Brad Miller (Member # 2) on 08-03-1999, 08:42 PM:

I know exactly what you're talking about. It drives me crazy. I've got a trailer where the 2nd half of the green band is like that. Talk about annoying! It was Star Trek 7...so that gives everyone an idea of how long this has been going on.

It looks like an old tv antenna with bad reception with rolling lower contrast lines. Typically it only lasts for several seconds, but it is highly distracting. It is definitely a lab problem as I've never seen it on two prints of the same movie in the same spot. The most recent one I've noticed it on was Thomas Crown Affair.

Posted by Joe Redifer (Member # 3) on 08-03-1999, 11:37 PM:

I noticed this one one of our prints of Runaway Bride as well, towards the end. I haven't checked out our other print. Does this happen on Fuji film stocks?

Posted by John Pytlak (Member # 331) on 08-04-1999, 09:27 AM:

Joe contacted me directly on this, and reading the other postings now gives me enough information to indicate that the horizontal wavy lines are probably "printer bars". In a contact printer, the negative and print film are brought into contact on a 64-tooth printer sprocket, and exposure occurs via a very narrow slit of light coming from the additive lamphouse. If the printer speed varies slightly, or there is slippage on the sprocket, the exposure time varies slightly as the film is transported past the slit of light, causing faint horizontal density bars. These printer bars are most apparent in scenes that were underexposed, since the printer aperture needs to close down for these light negatives, narrowing the slit of light even more. They will definitely be scene and printer dependent. If you can provide details (feature name, print number(s), reel number(s)), Kodak can get back to the lab and work with them to adjust the printer.

------------------
John Pytlak

Posted by Brad Miller (Member # 2) on 08-04-1999, 02:02 PM:

Thanks for the lab info, John! I don't think there's anyone here who has done any serious motion picture printing work, so the info is much appreciated.

I will start taking notes on this occurence. I have noticed it to be less frequent as of the last year or two, but it still pops up nonetheless. (Wish I could remember when it happened in that print of Runaway Bride I screened.) If anyone sees this, post the info here. Perhaps Mr. Pytlak can take such info to the labs and assist in taking care of this problem.

Posted by David Stambaugh (Member # 1102) on 04-16-2002, 10:11 AM:

This topic came up in the review thread for "Changing Lanes"; bumping it up. I notice this wavy, rolling line thing in maybe 1/3 of the movies I see. The print of "Changing Lanes" I saw definitely had it. Many others still do as well. Surprising that it doesn't get mentioned more often here. If I notice this in the future I'll try to remember to mention it in my "reviews". The first time I noticed it I thought it was a projection problem, but that clearly isn't the case.

Posted by John Pytlak (Member # 331) on 04-16-2002, 12:55 PM:

The "Changing Lanes" description of looking like a faint "roll bar" on a CRT display seems to fit the "printer bar" or "flutter bar" explanation. Was it most apparent in scenes that were underexposed (e.g., the scenes also tended to have low density "milky" or "smoky" blacks)?

"Flutter Bars" are described in the book "Motion Picture Film Processing" by Dominic Case, Focal Press Media Manuals, ISBN 0-240-51243-X, page 100.

------------------
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: http://www.kodak.com/go/motion

Posted by David Stambaugh (Member # 1102) on 04-16-2002, 01:07 PM:

Since I have nothing better to do today (I'm still a downsized unemployed loser, 6 months now...), I may go see "Changing Lanes" again, but at a different theater. I will pay particular attention to 1) Focus, and 2) Wavy Lines.

Hopefully Cinemark hasn't banned me for life yet. "No soup/movies for you!"

Posted by John Pytlak (Member # 331) on 04-16-2002, 01:21 PM:

Try to notice if the scenes most affected with the "rolling bars" also tend to be lower in contrast, with "smoky" blacks and more grain --- typical signs of underexposure. As I noted, underexposed negatives are much lower in density, making the printer reduce the light beam used for printing to a very narrow slit, so even the slightest speed variation in the printer shows up as a faint density variation "bar" across the image.

Posted by Brad Miller (Member # 2) on 04-16-2002, 03:20 PM:

I can answer that question for you John, no. The print I screened of Changing Lanes had a 5-10 second burst of the wavy "interference lines" once on every reel and it was on a variety of images.

Posted by John Pytlak (Member # 331) on 04-16-2002, 03:30 PM:

Any particular place in the reel? Start-Middle-Finish?

Did the bars "roll" up and down through the image, or did they hang in the same place (e.g., aligned with the perfs)? Were they neutral, or did they seem to have some coloration?

Posted by Brad Miller (Member # 2) on 04-16-2002, 03:40 PM:

Neutral, rolled, randomly throughout the reel (never in the same place).

Posted by Joe Redifer (Member # 3) on 04-16-2002, 03:56 PM:

I wish this effect could be videotaped. Well maybe it can but I've never tried. It's hard to tell if they are rolling up or down, they kind of fluctuate and could be perceived to be rolling either way it seems.

Posted by David Stambaugh (Member # 1102) on 04-16-2002, 04:00 PM:

I just saw the movie again, only at a different theater. No wavy lines this time, none at all.

Brad's characterization of these rolling bars is about right, although I think 5 secs. would be the longest I've ever seen them last. They fade in, reach a peak, then fade out. They have kind of a gray shading, and nothing in the image is being obscured. They roll rapidly from top to bottom of the image (at least that's what it looks like, might be an illusion). They really do look like something from a video display, not filmlike.

Posted by Brad Miller (Member # 2) on 04-16-2002, 04:02 PM:

At one point when I was in Colorado I found a green band with this phenomenon. My intention was to try and do a crappy "shoot the screen from the port window" 10 second video that could be downloaded as an example. Only problem, I don't have a video camera, couldn't find anyone with a video camera and I have no idea where I put that strip of film. (I highly doubt anyone would come running after me for duping the green band, but I didn't want to shoot off 10 seconds of a movie for copyright reasons.)

As to the rolling, no it's not rolling wildly, but there is definite rolling motion to it.

Not to intentionally keep slamming this one lab, but has anyone ever seen this phenomenon from a non-Deluxe Hollywood print? I haven't.

Posted by John Pytlak (Member # 331) on 04-16-2002, 09:55 PM:

We're letting the lab know about the concern, and will help them investigate the cause. Thanks.

Posted by Joseph Pandolfi (Member # 223) on 04-19-2002, 09:14 PM:

Thanks Joe & Brad for bringing this topic up. I noticed this a lot about a year ago, not to much now and mostly at a trailers green band. Once I was screening a print and this occured so bad on a outdoor scene that it looked like dusk for about a second before it hit a lab splice.

Posted by John Pytlak (Member # 331) on 04-22-2002, 08:16 AM:

Joseph said: "...it looked like dusk for about a second before it hit a lab splice."

Thanks for another clue to the cause. Does there seem to be a correlation with the lab splice? That is, does the banding tend to occur just before a lab splice?

Posted by Joe Redifer (Member # 3) on 04-22-2002, 10:10 AM:

It is not uncommon to see horrible color shifts before and after a lab splice due to the "rush rush rush" mentality of some labs that is destroying the quality of film. Of course those reels should be replaced right away. But the wavy lines are usually never around a lab splice and look totally different.

Posted by John Pytlak (Member # 331) on 04-22-2002, 11:14 AM:

Joe --- I was looking at the possibility that somehow the lab splice caused a slight disruption in the speed of the film as it went past the printer aperture.

The discoloration you mention is likely due to fogging from the darkroom "safelight" used to illuminate the splicer to aid the operator in making the lab splice --- sometimes it may take the operator a few seconds longer to make the splice, so some fogging occurs. It's usually colored blue or cyan. Severely fogged reels will be normally be replaced by the lab.

Posted by David Stambaugh (Member # 1102) on 04-22-2002, 11:17 AM:

So maybe we should be looking for correlation between the wavy line syndrome, and a lab splice, both on the same reel, even if they aren't near each other. ?

Posted by John Pytlak (Member # 331) on 04-22-2002, 11:28 AM:

David asked: "So maybe we should be looking for correlation between the wavy line syndrome, and a lab splice, both on the same reel, even if they aren't near each other. ?"

Yes. I was following up on Joseph Pandolfi's observation that the banding showed up just before a lab splice. Banding within a minute or so of the splice could be a good clue.

Posted by David Stambaugh (Member # 1102) on 05-05-2002, 06:47 PM:

The "Spiderman" print I just saw had the wavy line syndrome in both reel 4 and reel 5, roughly at the mid-point of each one. I didn't notice any lab splices. Aside from that the print was in perfect condition.

Posted by Darryl Spicer (Member # 711) on 05-05-2002, 07:43 PM:

I noticed this same effect on changing lanes also. During darker scenes. I did not notice them in the print of Spiderman that I screened.

Posted by Jacob Huber (Member # 1138) on 05-06-2002, 02:25 AM:

I didn't notice the wavy lines in Spiderman either. However, in 2 of our 3 prints, I've noticed what looks like a scratch, but it seems to be faded instead of black, green, yellow or white, kinda like this scratch-shaped part of the film was bleached out or something.

Posted by Joseph Pandolfi (Member # 223) on 05-07-2002, 01:19 PM:

John: It went to dusk was before it hit the lab splice. Another note I screened the open captioned print of Changing Lanes and almost the entire second half of reel 3 had that problem with the "wavy lines".

Posted by John Pytlak (Member # 331) on 05-07-2002, 01:27 PM:

When you get a print badly affected with the "wavy lines" or "rolling bars", report the print number and other details so the lab can investigate the cause. It sounds like the problem is random, and not often reported back to the lab.

------------------
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: http://www.kodak.com/go/motion

Posted by Jacob Huber (Member # 1138) on 05-08-2002, 02:00 AM:

Side note to my reply seated atop this page, both of the prints with the bleached-out scratch-like markings are from Deluxe Hollywood, whereas our good print is from Toronto.

Posted by Matt Close (Member # 996) on 05-08-2002, 05:07 AM:

My print of the 'Count of Monte Christo' has a vertical squiggly line up the left hand side on the last reel?????? It has a 'transparent effect' to it...... wierd..... Kinda looks like when you get a photo wet.

Posted by John Pytlak (Member # 331) on 05-08-2002, 07:13 AM:

Matt Close said: "My print of the 'Count of Monte Christo' has a vertical squiggly line up the left hand side on the last reel?????? It has a 'transparent effect' to it...... wierd..... Kinda looks like when you get a photo wet."

Blotches or vertical streaks along the far left hand side of the 35mm image are often related to soundtrack developer issues. If the thin viscous bead of potent caustic developer applied to the analog soundtrack during processing "bleeds" or splashes into the picture area, you will see it. Request a replacement reel.

------------------
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: http://www.kodak.com/go/motion

Posted by Sarah Werning (Member # 1251) on 05-08-2002, 08:34 PM:

Our print of Spider-man has the wavy-line, distorted color problem that seems to be what you're talking about. I had chalked it up to the color enhancement of our print. I've seen it a couple times before on color-enhanced prints. Our LOTR first four reels had that, plus dark splotches scattered throughout. Ick.

Sarah Werning
Chief of IMAX Projection
Regal IMAX Lincolnshire

Posted by Steve Kraus (Member # 476) on 05-08-2002, 10:59 PM:

Welcome aboard, Sarah!

Are you referring to the prints "specially enhanced" for showing in IMAX theatres? I believe those are just adjusted for the substandard screen illumination generally found in such situations. That's just a printing light (timing) setting and shouldn't cause any anomolies.

Posted by John Pytlak (Member # 331) on 05-09-2002, 07:10 AM:

Sarah said: "Our LOTR first four reels had that, plus dark splotches scattered throughout. Ick."

Again, a "wavy line" discoloration or density along the far left side of the 35mm image is likely soundtrack developer that has "bled" into the picture area. If you remove the projector aperture and project the analog soundtrack area on the screen, you'll see what I mean. "Dark splotches scattered throughout" are likely droplets of the soundtrack developer that splashed into the picture area. Request a replacement reel.

Steve is correct, these problems are not related to the lighter "enhanced" prints being made for IMAX theatres and drive-ins, which are simply printed at a lighter setting.

------------------
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: http://www.kodak.com/go/motion

Posted by Sarah Werning (Member # 1251) on 05-10-2002, 04:38 PM:

Ah, we are talking about different things then. Our wavy lines are hard to describe... For one thing, they do not stay in one place, they sort of move back and forth. They are not scratches or anything like that; rather, they look like the patterns you would get if you threw paint thinner on a freshly-painted wall and let it drip down. Uneven, lighter swashes of color that sort of move side to side and back on the screen. It tends to be several on screen at once and they are really annoying (to me, anyway). Most of the reel is affected; it doesn't necessarily affect other reels.

Now, I have only seen this on our reel three of Spider-man, and reels one to four of LOTR, but had talked with other people who had seen it on their prints. All of these prints were "color enhanced" (Technicolor's words, not mine) for 35mm presentations on IMAX screens, so that is why I had assumed it was inherent to these types of prints. It may be a common problem I've been fortunate to avoid in regular prints so far.

The soundtrack developer splashes sound like a good explanation for the LOTR splotches problem; or course I requested replacement reels immediately after I had screened LOTR the first time. The new reels looked much better.

Anyone else see this on 35mm prints, "enhanced" or otherwise?

Sarah Werning
Chief of IMAX Projection
Regal IMAX Lincolnshire

Posted by Gordon McLeod (Member # 33) on 05-10-2002, 05:18 PM:

Possibly a probelm when processing of uneven agitation of the processing solution or one of the washs

Posted by David Stambaugh (Member # 1102) on 05-10-2002, 05:52 PM:

Saw Spiderman with a group today (2nd time for me), in the same theater as before. This time since I knew the wavy lines were coming I paid a little more attention. In reel 4, the lines appeared at 13 mins into the reel; in reel 5, it was 10 mins in. And in both cases, the SDDS sound was affected. I'm not sure exactly what happens when the primary SDDS track drops out -- does it fall back to the secondary SDDS track, or to analog? Anyway both times when the wavy lines showed up, there was an audible click in the audio, a slight change in the sound character that lasted 4-5 seconds, then another click and a return to normal.

Just so we're sort of on the same page, these "wavy lines" are faint horizontal shadowy bars superimposed across the entire frame. They usually last for a few seconds, and they appear to be rolling downward (could be an optical illusion though).

Posted by John Pytlak (Member # 331) on 05-12-2002, 08:07 PM:

David said: "Anyway both times when the wavy lines showed up, there was an audible click in the audio, a slight change in the sound character that lasted 4-5 seconds, then another click and a return to normal.
Just so we're sort of on the same page, these "wavy lines" are faint horizontal shadowy bars superimposed across the entire frame. They usually last for a few seconds, and they appear to be rolling downward (could be an optical illusion though)."

The symptoms described could be caused by a slight "stutter" in the printer transport, or a bit of slippage in the gate. Sounds like it occurs randomly, so the lab would benefit if the print was returned with the details of the problem, so they could find and fix the cause.

------------------
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: http://www.kodak.com/go/motion

Posted by David Stambaugh (Member # 1102) on 06-07-2002, 10:13 PM:

At the risk of beating this wavy line issue to death, I finally got around to seeing "About A Boy" today, and it had by far the worst case of wavy line syndrome I've seen. Almost every reel had it, and sometimes the wavy lines kept up for a good 30 seconds or so. Overall the lab work on this print was pretty lousy: 1 reel was greenish, and the tail of another reel (right after the 1st reel change cue) had wacked out colors.

Posted by Manny Knowles (Member # 1171) on 06-08-2002, 03:30 AM:

SPIDERMAN has it here too.