Film-Tech Forum ARCHIVE: What to do about motorboating prints?

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Posted by John Hawkinson (Member # 1135) on 03-09-2002, 11:24 PM:

This weekend, we're running all 3 Indiana Jones movies. As you might expect, prints are not in the best condition. But for the most part they're better than can be expected. One annoying problem is that some reels of Raiders of the Lost Ark (Technicolor's only print, bleh) and Indiana Jones and the Last Crusade exhibit motorboating on the right channel.

I assume this is due to some sort of failure over time, though the precise failure I don't know what. There are also ocassional visual registration problems, where the corner of the frame becomes visibule in the aperture for seconds at a time.

I'm pretty sure that our sound heads are in alignment; buzz track was run recently, though I'll run it again soon to verify, but other prints have been just fine, and the visual registration issues seem to be a sure confirmation of a print problem.

So what's the fix? One thought was to try to move the photocell
by hand until it sounds "OK". This seems a dangerous plan since the problem goes and comes and it seems conceivable that alginment sufficient to play it would fail to play properly registered soundtracks. I'm loathe to try this.

The solution I'm going with is to patch the left premplifier output off our CP65 into the CP65 Mag/Aux center channel, and run the affected portions of the film that way (with the booth monitors listening to the right preamp output to go back to regular Dolby A when the affected portions of the print clear).

Is there a better solution? Any good advice for this sort of thing?

Oh yeah -- if you book Last Crusade and have any option, don't get it from TES if you can get it from ETS.

--jhawk

Posted by Brad Miller (Member # 2) on 03-09-2002, 11:27 PM:

All of the Indiana Jones movies are Paramount titles and can only be had through ETS. No studio distributes through both depots.

Your prints have shrunk, that is why you are hearing the motorboating. You didn't say what kind of projector/sound head you had.

Posted by John Hawkinson (Member # 1135) on 03-09-2002, 11:31 PM:

Sorry. They're Century R3s. I'm curious how this actually matters in terms of solutions though...

Technicolor does indeed have prints Last Crusade and one print of Radiers of the Lost Ark, but not (afaik) Temple of Doom.

--jhawk

Posted by Scott Norwood (Member # 30) on 03-09-2002, 11:36 PM:

There's definitely more than one print of Raiders. Actually, the Avon Cinema in Providence, RI is running it this weekend. Maybe they have the new print that was struck a year or so ago (which I think had an SR track instead of the original Dolby A track).

Does the motorboating happen on both projectors? How does it sound when you run it in mono?

Posted by Brad Miller (Member # 2) on 03-09-2002, 11:37 PM:

I don't recommend you doing this as normal practice, but since you have R3s there *is* a way you can cheat your way through this. You should check with your tech first to make sure he won't come attack you later though.

Hopefully the lateral guide arm that rests on the top of the sound drum has a round knob. Some of them have a square knob. If you have a round knob, take a piece of masking tape and cut out a tiny arrow out of masking tape and apply it to the edge pointing straight up. If you have a square knob, take a marker and put a dot on one of the 4 sides and make a note of which direction it is pointing (example: pointing at 1:00). Below I have a picture of this done with white Artist's tape for clarity.

Now run your print and assuming the tech didn't tighten it down too tightly, slowly rotate it until your motorboating is gone. Don't turn it more than 1/2 rotation. If it doesn't clear up within 1/2 turn, you are going the wrong way. Then just make damned sure you put it back. Also beware you may not be able to get it exactly back to *perfect*, but if your tech doesn't mind running through another A-chain to help you get through these special shows, that should be enough of a rig to solve your problems. Also note that you will probably not have perfect Dolby NR decoding and matrix steering, but with a shrunken print you've got to do whatever you can. No test film can possibly align it.

Posted by John Hawkinson (Member # 1135) on 03-09-2002, 11:43 PM:

I believe the new print of Raiders is not handled through TES.

Thanks for the recommendation, Brad. Indeed, round knobs here.
I suppose adjusting the lateral roller is a lot easier than messing with the photocell position. We can certainly redo the A-chain after this, though I am a bit concerned with how the non-shrunken portions of the print will play...

--jhawk

Posted by Brad Miller (Member # 2) on 03-09-2002, 11:47 PM:

This is an old trick I came up with when we used to run repertory movies at Northpark. It allowed us to run the normal daytime shows with the arrow pointing at 12:00 and the repertory shows at whatever setting we found balanced out best for the shrunken repertory prints. In your case, you may find that reel 1 has to play at 2:00, reel 2 may play at 12:00, reel 3 may play at 12:30 and so forth. You will have to do a pre-screening to find out.

Beware this is certainly a "rig" and is not the correct way to do it, but since the odds of you being able to have a tech perform an A-chain based upon a shrunken print between each show is out of the question, this one will get you through. Just remember whenever this is all over to get your tech back in there to align it back precisely.

Posted by Steve Kraus (Member # 476) on 03-10-2002, 12:05 AM:

If you have time for a test run you could take detailed notes on the best guide position (as marked per Brad's suggestion) in different parts of each reel and keep it corrected throughout the show.

O.T.: Hmm...70mm guides? Get thy JJ rebuilt for by-pass!

Posted by Brad Miller (Member # 2) on 03-10-2002, 12:14 AM:

Why is that Steve? Personally I dislike the JJs that route the film outside of the soundhead.

Posted by Steve Kraus (Member # 476) on 03-10-2002, 12:37 AM:

I presume that they changed it and created a retrofit because the close clearances led to scratched film if something were a bit out of adjustment. Perhaps this became more likely with the advent of platter operation? Maybe Steve G. could shed more light on why it was redesigned but it's probably safe to say it was for cause.

Posted by Brad Miller (Member # 2) on 03-10-2002, 12:43 AM:

You may be right. Still, even though it is just a tad bit more hassle to thread 70mm film inside the optical soundhead, I have always preferred it over running it out and around. I also think it is a bit more foolproof in the threading should the unmentionable happen (some uncaring/untrained newbie running 70mm that is).

will know. He knows everything.

Posted by John Walsh (Member # 168) on 03-10-2002, 08:07 AM:

I had those forks cut back on our JJ's because the film curved back so far it was scratching. In one case it was so bad, I removed the entire exciter lamp assembly.

That JJ bypass soultion probably works OK, but I don't like it because it's kinda an ulgy fix!

Posted by Steve Kraus (Member # 476) on 03-10-2002, 10:08 AM:

My personal JJ didn't have a legitimate R-something 70mm SH to go under it so in converting an R3 by-pass was the way to go although that aspect wasn't finished until after I had sold the machine. Mark machined the JJ casting for by-pass as per the Strong blueprint but another fellow turned rollers out of brass stock rather than buy the actual kit.

John remarked:
>That JJ bypass soultion probably works OK, but I don't like it
>because it's kinda an ulgy fix!

The rollers outside the SH look just like those on the R8 interlock setup so I'm used to that. What is truly ugly is that black JJ Strong was showing. Does anyone know if that is the standard on new production? (Is there any new production?)

Brad admitted:
> will know. He knows everything.

Wow...we agree on something!

Posted by Steve Guttag (Member # 268) on 03-10-2002, 04:27 PM:

The reason? As far as I can tell, economics. The R-3 now works for both JJ and SA operation. No need for two soundheads to be available.

The noted film damage did indeed occur on the soundhead (excessive film curl would have the picture area rub the middle of the film). However, I have never found a situation where this couldn't be adjusted out.

I am with Brad on this one, I MUCH prefer running the 70mm film through the soundhead rather than around it. Unlike on other 70mm machines (like Norelco or Cinemeccanica) the 70mm film path on the JJ (or even the Simplex PR-3570), the last sprocket moving the film out of the system is in the projector head itself. Each roller in the film path adds some amount of friction. Depending on one's platter placement and strength of the take up, this can cause the film to sag, bounce or even stall on it's way back to the platter.

One thing I'm happy to say is that Kelmar supports the R-50 soundhead (and R-20 for you standard drive lovers) so your 70mm film path can properly be routed though the optical soundhead on onto your take-up device (preferably a reel, of course ). You have to order the "JJ" version of the reverse scan reader but it works quite nicely.

Steve

------------------
"Old projectionists never die, they just changeover!"

Posted by Bill Enos (Member # 440) on 03-10-2002, 04:28 PM:

We ran Raiders 2 weeks ago at midnite. The print came from Paramount Classics and was a nearly perfect recent print. Whatever you can get from Paramount or WB Classics will undoubtedly be better than what will be had from regular diatributors.

Posted by John Hawkinson (Member # 1135) on 03-10-2002, 04:37 PM:

Oops, sorry Scott, got a bit distracted and missed your questions.

In regards to being the "only print," I may have misinterpreted what Technicolor said to me and it may be that all their prints are booked this weekend, rather than this being the only one.

The motorboating does happen on both projectors, though not perfectly consistently, and it also happens on our pair of Bauer U4s.

It does not sound appreciably better in mono, no.

--jhawk

Posted by Brad Miller (Member # 2) on 03-10-2002, 04:58 PM:

John, did you book that print through Swank or some other college-type distributor?

Posted by John Hawkinson (Member # 1135) on 03-10-2002, 04:59 PM:

Yes, all 3 prints were booked through Swank.

--jhawk

Posted by Jerry Chase (Member # 660) on 03-10-2002, 05:25 PM:

jhawk, I think Brad is right about the shrinkage, but for the record there is a slim possibility that there could be print damage in or at the edge of the soundtrack area from a misthreaded sprocket. If damage is every other reel or not on all reels, I'd check the soundtrack out for tiny pinpricks or scratches.

Print edges can get shaved, too. A worn Norelco band once split about a millimeter of the outboard side of "Love Story" on me. It wore through, hit a splice, and by the time I was through with the changeover in the other booth I had a pile of about 90 feet of 1 mm film by the takeup reel. It took me a few seconds to even figure out what it was and where it was coming from. Since it was the final part of the run, during the last showings I had to press against the edge of the film to keep things more or less aligned during that section. After that experience I demanded new bands.

Posted by Steve Kraus (Member # 476) on 03-10-2002, 07:47 PM:

Steve Guttag opined:
>The reason? As far as I can tell, economics. The R-3 now works for
>both JJ and SA operation. No need for two soundheads to be available.

Hmm...interesting. I thought there was a difference in magazine or arm mounting plus how are the by-pass rollers attached? Or do you mean that only new R-3's can be used under a JJ?

Posted by Scott Norwood (Member # 30) on 03-10-2002, 09:14 PM:

So, wait, on new-model JJs the 70mm film path does not pass through the soundhead at all? I guess that this kind of makes sense, but I'm having a hard time visualizing it. When did they change the design?

Posted by Steve Guttag (Member # 268) on 03-10-2002, 10:11 PM:

The change happened under ORC's watch. In the Mid '80s the R-50 was still current. In 1987 was the first JJ I installed with the R3 under the JJ.

Scott, the current JJ is a hideous thing...there is a slot cut out of the front and two additional roller are added to allow the film to be guided out to the slot. On the soundhead (optical) this ugly roller contraption is mounted so the film comes out the front and goes around the optical soundhead to meet up with the cue detector.

Steve, since the magazines were discontinued before the switch I'll rule that as a reason out. I'm pretty sure the JJ is a bolt up to the MR3 soundhead. I recall using our mule R3 soundhead to run one in for intermittent rebuilds.

I just think someone had the bright idea (no doubt after one of the biggies complained about a "bunch-up" after a break in the sound head) hey we only need to make one soundhead and the 35/70 on is but a fraction of the total sales. On the Simplex the 35/70 soundhead is identical except for the two bypass rollers whose holes are present on all units.

Steve

Posted by John Hawkinson (Member # 1135) on 03-10-2002, 11:57 PM:

OK, we're done with that run. Looks like its not going to break even $

Anyhow, Brad's lateral roller adjustment worked well for Raiders. I hadn't personally listened to the lossage on Last Crusade, and it seems to just be dirt or some other damage on the soundtrack. Adjusting the lateral roller doesn't help it, nor is it confined to a single optical channel, nor is it sufficiently regular in pitch to be motorboating. I would say it was clearly dirt, though that was not obvious from inspection, nor was the rest of the print visually dirty (surprisingly enough).

Ah, well. We'll see how much post-mortem I am inclined to do on this the coming week.

--jhawk

Posted by Aaron Sisemore (Member # 145) on 03-11-2002, 01:12 AM:

>>Yes, all 3 prints were booked through Swank.<<

TES handles Swank's library, explaining why TES handled your prints. Otherwise (thru Paramount) they would have been handled by ETS.

-Aaron

Posted by John Hawkinson (Member # 1135) on 03-11-2002, 01:26 AM:

No, that's not true. Swank goes through both TES and ETS, depending.

--jhawk

Posted by Leo Enticknap (Member # 534) on 03-11-2002, 03:32 AM:

If the print's width has shrunk so much that it's pushed the soundtrack out of alignment relative to the pickup, I would have thought that the length must also have shrunk so much that vertical stability and perforation damage would be causing problems...

Posted by Brad Miller (Member # 2) on 03-11-2002, 03:57 AM:

Many projectors can play shrunken film quite nicely, Centurys for example.

Posted by Leo Enticknap (Member # 534) on 03-11-2002, 04:04 AM:

True. I've never used a Century; in my experience FP-20s are the kindest to shrunk and brittle triacetate, possibly because the pitch of the sprockets is so thin. I've even run a 1928 diacetate (butyrate) print on one, without any problem at all. The soundtrack was fine too, but it was variable density, which I guess would be less susceptible to lateral shift than variable area.

But there are some projectors which would eat the perforations on severely shrunken film for breakfast - Gaumont-Kalee 38s, for example.

Posted by Joe Beres (Member # 678) on 03-11-2002, 08:36 AM:

Swank has no 35mm library actually. They do not own a single 35mm print. If you call Swank tobook a 35mm print through Swank, then they call the studio that owns the print. If the studio approves the rental, then the studio has either the depot or vault and has the printy shipped to you. So, who handles the print has nothing to do with Swank, it depends on where the particluar studio's prints are kept. It's a really problematic process that has caused us unbelieveable problems with booking and receiving films booked through them.

They do hald a large collection of 16mm prints however. If you book 16mm from them, it is shipped directly from their facility.

Posted by John Hawkinson (Member # 1135) on 03-11-2002, 10:22 AM:

Perhaps some clarification is in order.

Generally, Swank prints go through the studios and thus TES or ETS as appropriate. However, Swank does in fact own a handful of 35mm prints. Apparently this happens when someone pays them enough cash to have a new print of something struck. Those prints are handled by TES, and are different from the regular TES prints of a given film.

It seems that there was a recent print of Raiders that was such a Swank-owned print, though supposedly it is now trashed. I assume this is a different print than the one that I hear was struck recently for theatrical/arthouse use, and presumably different from the print Avon is running that Scott referenced.

--jhawk

Posted by Joe Beres (Member # 678) on 03-11-2002, 10:35 AM:

Our rep at Swank has told me that they do not hold any 35mm prints, so that is news to me, but it certainly wouldn't be the first bit of misinformation that they have provided. Perhaps they do not actually own the prints, but the studios provide a print to their respective depot/vault that is only for Swank's non-theatrical use.

Posted by Tao Yue (Member # 836) on 03-11-2002, 03:04 PM:

Joe Beres said:

quote:

Perhaps they do not actually own the prints, but the studios provide a print to their respective depot/vault that is only for Swank's non-theatrical use.

I believe that is the case, as some prints arrive labelled "Swank/title of film" with a one-digit print number (as opposed to being labeled just with the title and a multi-digit print number).

Posted by John Pytlak (Member # 331) on 03-12-2002, 02:18 PM:

Depending on the age and storage conditions of the print, "aging shrinkage" on acetate color print film can approach 0.40% lengthwise and 0.50% widthwise shrinkage. With the polyester (ESTAR) film base used on today's Kodak VISION Color Print Film, the potential aging shrinkage is only 0.04%:

http://www.kodak.com/country/US/en/motion/support/h1/baseP.shtml

------------------
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 John Hawkinson (Member # 1135) on 03-12-2002, 04:46 PM:

So, tell us John, what's the difference between 2383 and 2393 (premier)? It wasn't obvious to me leafing around...

--jhawk

Posted by Frank Angel (Member # 248) on 03-16-2002, 07:27 AM:

John H. is right -- Swank does own some 35mm prints; the print we got of WEST SIDE STORY last month was nearly mint, and a great surprise for us as MGM sent us one of their "best" prints last year and it was pretty battered up. Swank had this new print struck because some execs at Turner payed for it for reasons unknown. Otherwise, as John said, execpt for these very few odd titles, Swank doesn't own 35mm prints; they get them from the studios for their non-theatrical clients who happen to have 35mm setups.